27

我正在创建一个应用程序，其中我需要画廊中的所有图像到我的应用程序中，其中有一个 girdview。我希望所有文件夹中的所有图像都出现在 gridview 中。

String[] proj = { MediaStore.Images.Media.DATA, MediaStore.Images.Media._ID };
actualimagecursor = managedQuery(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, proj,
                      null, null, MediaStore.Images.Media.DEFAULT_SORT_ORDER);

actual_image_column_index = actualimagecursor.getColumnIndexOrThrow(MediaStore.Images.Media._ID);
actualimagecursor.moveToPosition(position);
String i = actualimagecursor.getString(actual_image_column_index);

我已将此代码添加到我的代码中，但我只获得了 sd 卡图像，没有获得其他文件夹图像。如何从图库中获取所有图像？

提前致谢。

4

7 回答 7

42

在Glide的帮助下工作的解决方案。额外的部分是 Glide 将自动播放 Gif。

在此处输入图像描述

import java.util.ArrayList;

import android.app.Activity;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.provider.MediaStore.MediaColumns;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;
import android.widget.Toast;

import com.bumptech.glide.Glide;

/**
 * The Class GallarySample.
 */
public class GallarySample extends Activity {

    /** The images. */
    private ArrayList<String> images;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.gallery_activity);

        GridView gallery = (GridView) findViewById(R.id.galleryGridView);

        gallery.setAdapter(new ImageAdapter(this));

        gallery.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> arg0, View arg1,
                    int position, long arg3) {
                if (null != images && !images.isEmpty())
                    Toast.makeText(
                            getApplicationContext(),
                            "position " + position + " " + images.get(position),
                            300).show();
                ;

            }
        });

    }

    /**
     * The Class ImageAdapter.
     */
    private class ImageAdapter extends BaseAdapter {

        /** The context. */
        private Activity context;

        /**
         * Instantiates a new image adapter.
         *
         * @param localContext
         *            the local context
         */
        public ImageAdapter(Activity localContext) {
            context = localContext;
            images = getAllShownImagesPath(context);
        }

        public int getCount() {
            return images.size();
        }

        public Object getItem(int position) {
            return position;
        }

        public long getItemId(int position) {
            return position;
        }

        public View getView(final int position, View convertView,
                ViewGroup parent) {
            ImageView picturesView;
            if (convertView == null) {
                picturesView = new ImageView(context);
                picturesView.setScaleType(ImageView.ScaleType.FIT_CENTER);
                picturesView
                        .setLayoutParams(new GridView.LayoutParams(270, 270));

            } else {
                picturesView = (ImageView) convertView;
            }

            Glide.with(context).load(images.get(position))
                    .placeholder(R.drawable.ic_launcher).centerCrop()
                    .into(picturesView);

            return picturesView;
        }

        /**
         * Getting All Images Path.
         *
         * @param activity
         *            the activity
         * @return ArrayList with images Path
         */
        private ArrayList<String> getAllShownImagesPath(Activity activity) {
            Uri uri;
            Cursor cursor;
            int column_index_data, column_index_folder_name;
            ArrayList<String> listOfAllImages = new ArrayList<String>();
            String absolutePathOfImage = null;
            uri = android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI;

            String[] projection = { MediaColumns.DATA,
                    MediaStore.Images.Media.BUCKET_DISPLAY_NAME };

            cursor = activity.getContentResolver().query(uri, projection, null,
                    null, null);

            column_index_data = cursor.getColumnIndexOrThrow(MediaColumns.DATA);
            column_index_folder_name = cursor
                    .getColumnIndexOrThrow(MediaStore.Images.Media.BUCKET_DISPLAY_NAME);
            while (cursor.moveToNext()) {
                absolutePathOfImage = cursor.getString(column_index_data);

                listOfAllImages.add(absolutePathOfImage);
            }
            return listOfAllImages;
        }
    }
}

gridView 的布局文件

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <GridView
        android:id="@+id/galleryGridView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:columnWidth="280dp"
        android:gravity="center"
        android:horizontalSpacing="2dp"
        android:numColumns="2"
        android:padding="2dp"
        android:stretchMode="columnWidth"
        android:verticalSpacing="2dp" >
    </GridView>

</RelativeLayout>

Kotlin使用和更新 2019 LoderManager：

** 2) 使用 LoderManager 加载异步加载图像。**

LoaderManager.LoaderCallbacks<Cursor>在您的活动或片段类中实现

覆盖 LoaderCallbacks 这个：

private val IMAGE_LOADER_ID = 1
private val listOfAllImages = ArrayList<String>()



override fun onCreateLoader(p0: Int, p1: Bundle?): Loader<Cursor> {

    val uri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI
    val projection = arrayOf(MediaColumns.DATA, MediaStore.Images.Media.BUCKET_DISPLAY_NAME)
    val selection: String? = null     //Selection criteria
    val selectionArgs = arrayOf<String>()  //Selection criteria
    val sortOrder: String? = null

    return CursorLoader(
            activity!!.applicationContext,
            uri,
            projection,
            selection,
            selectionArgs,
            sortOrder)
}

override fun onLoadFinished(loader: Loader<Cursor>, cursor: Cursor?) {

    cursor?.let {
        val columnIndexData = it.getColumnIndexOrThrow(MediaColumns.DATA);

        while (it.moveToNext()) {

            listOfAllImages.add(it.getString(columnIndexData));
        }
    }
}


override fun onLoaderReset(loader: Loader<Cursor>) {
}

最后在 onCreate 方法初始化加载器上：

 loaderManager.initLoader(IMAGE_LOADER_ID,
                null,
                this)

3) 使用Kotlin Coroutine&ViewModel

实现'androidx.core:core-ktx:1.0.2'

实施 'org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.0-M2'

实施“org.jetbrains.kotlinx:kotlinx-coroutines-android:1.3.0-M2”

Coroutine使用上下文创建视图模型

  /**
   * Use Coroutines To Load Images
   */
   class ImageViewModel : ViewModel(), CoroutineScope {

    private val job = Job()
    override val coroutineContext: CoroutineContext
        get() = job + Dispatchers.Main

    private var imagesLiveData: MutableLiveData<List<String>> = MutableLiveData()
    fun getImageList(): MutableLiveData<List<String>> {
        return imagesLiveData
    }

    /**
     * Getting All Images Path.
     *
     * Required Storage Permission
     *
     * @return ArrayList with images Path
     */
    internal fun loadImagesfromSDCard(): ArrayList<String> {
        val uri: Uri = android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI
        val cursor: Cursor?
        val column_index_data: Int
        val column_index_folder_name: Int
        val listOfAllImages = ArrayList<String>()
        var absolutePathOfImage: String? = null

        val projection = arrayOf(MediaStore.MediaColumns.DATA, MediaStore.Images.Media.BUCKET_DISPLAY_NAME)

        cursor = AppController.globalContentResolvere!!.query(uri, projection, null, null, null)

        column_index_data = cursor!!.getColumnIndexOrThrow(MediaStore.MediaColumns.DATA)
        column_index_folder_name = cursor!!
            .getColumnIndexOrThrow(MediaStore.Images.Media.BUCKET_DISPLAY_NAME)
        while (cursor!!.moveToNext()) {
            absolutePathOfImage = cursor!!.getString(column_index_data)
            listOfAllImages.add(absolutePathOfImage)
        }
        return listOfAllImages
    }

    fun getAllImages() {
        launch(Dispatchers.Main) {
            imagesLiveData.value = withContext(Dispatchers.IO) {
                loadImagesfromSDCard()
            }
        }
    }
}

然后使用viewModel

 val imageViewModel = ViewModelProviders.of(this).get(ImageViewModel::class.java)

    imageViewModel.getImageList().observe(this, Observer<List<String>> { listOfImage ->
        imageWidgetStatus.text = """ Found ${listOfImage.size} Images"""


    // load images
    imageViewModel.getAllImages()
于 2016-04-23T19:31:23.813 回答
6

您正在使用MediaStore.Images.Media.EXTERNAL_CONTENT_URI的只是外部存储。对于内部有MediaStore.Images.Media.INTERNAL_CONTENT_URI. 您可以使用MergeCursor组合两个查询结果。

于 2013-09-03T11:02:20.053 回答
4 
 public static ArrayList<String> fetchGalleryImages(Activity context) {
        ArrayList<String> galleryImageUrls;
        final String[] columns = {MediaStore.Images.Media.DATA, MediaStore.Images.Media._ID};//get all columns of type images
        final String orderBy = MediaStore.Images.Media.DATE_TAKEN;//order data by date

        Cursor imagecursor = context.managedQuery(
                MediaStore.Images.Media.EXTERNAL_CONTENT_URI, columns, null,
                null, orderBy + " DESC");//get all data in Cursor by sorting in DESC order

        galleryImageUrls = new ArrayList<String>();

        for (int i = 0; i < imagecursor.getCount(); i++) {
            imagecursor.moveToPosition(i);
            int dataColumnIndex = imagecursor.getColumnIndex(MediaStore.Images.Media.DATA);//get column index
            galleryImageUrls.add(imagecursor.getString(dataColumnIndex));//get Image from column index

        }
        Log.e("fatch in","images");
        return galleryImageUrls;
    }
于 2018-06-29T07:05:10.050 回答
4 
Intent intent = new Intent();
intent.setType("image/*");
intent.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(Intent.createChooser(intent, "Select Picture"), SELECT_PICTURE);
于 2015-10-17T08:53:07.417 回答
2

您无法仅通过一个查询获得结果，请尝试实例化两个不同的游标。由于您已经添加了EXTERNAL_CONTENT_URI，这里是另一个：

 actualimagecursor2 = managedQuery(MediaStore.Images.Media.INTERNAL_CONTENT_URI, proj,
                      null, null, MediaStore.Images.Media.DEFAULT_SORT_ORDER);
于 2013-09-03T11:07:58.533 回答
2

从此处下载源代码（以编程方式从 android 中的图库中获取所有图像）

activity_main.xml

<RelativeLayout android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#ffffff"
xmlns:android="http://schemas.android.com/apk/res/android">


<GridView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/gv_folder"
    android:numColumns="2"
    android:layout_marginLeft="10dp"
    android:layout_marginRight="10dp"></GridView>


</RelativeLayout>

MainActivity.java

package galleryimages.galleryimages;

import android.Manifest;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.database.Cursor;
import android.net.Uri;
import android.provider.MediaStore;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.GridView;
import android.widget.Toast;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {
public static ArrayList<Model_images> al_images = new ArrayList<>();
boolean boolean_folder;
Adapter_PhotosFolder obj_adapter;
GridView gv_folder;
private static final int REQUEST_PERMISSIONS = 100;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    gv_folder = (GridView)findViewById(R.id.gv_folder);

    gv_folder.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
            Intent intent = new Intent(getApplicationContext(), PhotosActivity.class);
            intent.putExtra("value",i);
            startActivity(intent);
        }
    });


    if ((ContextCompat.checkSelfPermission(getApplicationContext(),
            Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) && (ContextCompat.checkSelfPermission(getApplicationContext(),
            Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED)) {
        if ((ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this,
                Manifest.permission.WRITE_EXTERNAL_STORAGE)) && (ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this,
                Manifest.permission.READ_EXTERNAL_STORAGE))) {

        } else {
            ActivityCompat.requestPermissions(MainActivity.this,
                    new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE, Manifest.permission.READ_EXTERNAL_STORAGE},
                    REQUEST_PERMISSIONS);
        }
    }else {
        Log.e("Else","Else");
        fn_imagespath();
    }



}

public ArrayList<Model_images> fn_imagespath() {
    al_images.clear();

    int int_position = 0;
    Uri uri;
    Cursor cursor;
    int column_index_data, column_index_folder_name;

    String absolutePathOfImage = null;
    uri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;

    String[] projection = {MediaStore.MediaColumns.DATA, MediaStore.Images.Media.BUCKET_DISPLAY_NAME};

    final String orderBy = MediaStore.Images.Media.DATE_TAKEN;
    cursor = getApplicationContext().getContentResolver().query(uri, projection, null, null, orderBy + " DESC");

    column_index_data = cursor.getColumnIndexOrThrow(MediaStore.MediaColumns.DATA);
    column_index_folder_name = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.BUCKET_DISPLAY_NAME);
    while (cursor.moveToNext()) {
        absolutePathOfImage = cursor.getString(column_index_data);
        Log.e("Column", absolutePathOfImage);
        Log.e("Folder", cursor.getString(column_index_folder_name));

        for (int i = 0; i < al_images.size(); i++) {
            if (al_images.get(i).getStr_folder().equals(cursor.getString(column_index_folder_name))) {
                boolean_folder = true;
                int_position = i;
                break;
            } else {
                boolean_folder = false;
            }
        }


        if (boolean_folder) {

            ArrayList<String> al_path = new ArrayList<>();
            al_path.addAll(al_images.get(int_position).getAl_imagepath());
            al_path.add(absolutePathOfImage);
            al_images.get(int_position).setAl_imagepath(al_path);

        } else {
            ArrayList<String> al_path = new ArrayList<>();
            al_path.add(absolutePathOfImage);
            Model_images obj_model = new Model_images();
            obj_model.setStr_folder(cursor.getString(column_index_folder_name));
            obj_model.setAl_imagepath(al_path);

            al_images.add(obj_model);


        }


    }


    for (int i = 0; i < al_images.size(); i++) {
        Log.e("FOLDER", al_images.get(i).getStr_folder());
        for (int j = 0; j < al_images.get(i).getAl_imagepath().size(); j++) {
            Log.e("FILE", al_images.get(i).getAl_imagepath().get(j));
        }
    }
    obj_adapter = new Adapter_PhotosFolder(getApplicationContext(),al_images);
    gv_folder.setAdapter(obj_adapter);
    return al_images;
}

@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);

    switch (requestCode) {
        case REQUEST_PERMISSIONS: {
            for (int i = 0; i < grantResults.length; i++) {
                if (grantResults.length > 0 && grantResults[i] == PackageManager.PERMISSION_GRANTED) {
                    fn_imagespath();
                } else {
                    Toast.makeText(MainActivity.this, "The app was not allowed to read or write to your storage. Hence, it cannot function properly. Please consider granting it this permission", Toast.LENGTH_LONG).show();
                }
            }
        }
    }
}

}

adapter_photosfolder.xml

   <?xml version="1.0" encoding="utf-8"?>
    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">


    <LinearLayout
        android:layout_width="match_parent"
        android:orientation="vertical"
        android:layout_marginTop="10dp"
        android:layout_marginLeft="10dp"
        android:background="@drawable/drawable_photofolder"
        android:layout_marginRight="10dp"
        android:layout_marginBottom="10dp"
        android:layout_height="match_parent">
    <ImageView
        android:layout_width="150dp"
        android:layout_gravity="center"
        android:layout_height="150dp"
        android:id="@+id/iv_image"/>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/tv_folder"
        android:textStyle="bold"
        android:textColor="#000000"
        android:layout_marginLeft="10dp"
        android:textSize="15dp"/>

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/tv_folder2"
            android:textColor="#dfdfdf"
            android:layout_marginBottom="10dp"
            android:layout_marginLeft="10dp"
            android:textSize="15dp"/>
    </LinearLayout>

    <RelativeLayout
        android:layout_width="match_parent"
        android:id="@+id/rl_select"
        android:alpha="0.5"
        android:layout_height="match_parent">

    </RelativeLayout>

    </RelativeLayout>

Adapter_PhotosFolder.java

    package galleryimages.galleryimages;


    import android.content.Context;
    import android.util.Log;
    import android.view.LayoutInflater;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.ArrayAdapter;
    import android.widget.ImageView;
    import android.widget.TextView;

    import com.bumptech.glide.Glide;
    import com.bumptech.glide.load.engine.DiskCacheStrategy;

    import java.util.ArrayList;


     public class Adapter_PhotosFolder extends ArrayAdapter<Model_images> {

    Context context;
    ViewHolder viewHolder;
    ArrayList<Model_images> al_menu = new ArrayList<>();


    public Adapter_PhotosFolder(Context context, ArrayList<Model_images> al_menu) {
        super(context, R.layout.adapter_photosfolder, al_menu);
        this.al_menu = al_menu;
        this.context = context;


    }

    @Override
    public int getCount() {

        Log.e("ADAPTER LIST SIZE", al_menu.size() + "");
        return al_menu.size();
    }

    @Override
    public int getItemViewType(int position) {
        return position;
    }

    @Override
    public int getViewTypeCount() {
        if (al_menu.size() > 0) {
            return al_menu.size();
        } else {
            return 1;
        }
    }

    @Override
    public long getItemId(int position) {
        return position;
    }


    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {

        if (convertView == null) {

            viewHolder = new ViewHolder();
            convertView = LayoutInflater.from(getContext()).inflate(R.layout.adapter_photosfolder, parent, false);
            viewHolder.tv_foldern = (TextView) convertView.findViewById(R.id.tv_folder);
            viewHolder.tv_foldersize = (TextView) convertView.findViewById(R.id.tv_folder2);
            viewHolder.iv_image = (ImageView) convertView.findViewById(R.id.iv_image);


            convertView.setTag(viewHolder);
        } else {
            viewHolder = (ViewHolder) convertView.getTag();
        }

        viewHolder.tv_foldern.setText(al_menu.get(position).getStr_folder());
            viewHolder.tv_foldersize.setText(al_menu.get(position).getAl_imagepath().size()+"");



        Glide.with(context).load("file://" + al_menu.get(position).getAl_imagepath().get(0))
                .diskCacheStrategy(DiskCacheStrategy.NONE)
                .skipMemoryCache(true)
                .into(viewHolder.iv_image);


        return convertView;

    }

    private static class ViewHolder {
        TextView tv_foldern, tv_foldersize;
        ImageView iv_image;


    }


    }

**PhotosActivity.java**
    package galleryimages.galleryimages;
    import android.app.Activity;
    import android.os.Bundle;
    import android.support.v7.app.AppCompatActivity;
    import android.widget.GridView;


    public class PhotosActivity extends AppCompatActivity {
    int int_position;
    private GridView gridView;
    GridViewAdapter adapter;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        gridView = (GridView)findViewById(R.id.gv_folder);
        int_position = getIntent().getIntExtra("value", 0);
        adapter = new GridViewAdapter(this,MainActivity.al_images,int_position);
        gridView.setAdapter(adapter);
    }
}

**GridViewAdapter.java**

package galleryimages.galleryimages;


    import android.app.Activity;
    import android.content.Context;
    import android.util.Log;
    import android.view.LayoutInflater;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.ArrayAdapter;
    import android.widget.BaseAdapter;
    import android.widget.ImageView;
    import android.widget.TextView;

    import com.bumptech.glide.Glide;
    import com.bumptech.glide.load.engine.DiskCacheStrategy;


    import java.util.ArrayList;
    import java.util.List;


    public class GridViewAdapter extends ArrayAdapter<Model_images> {

    Context context;
    ViewHolder viewHolder;
    ArrayList<Model_images> al_menu = new ArrayList<>();
    int int_position;


    public GridViewAdapter(Context context, ArrayList<Model_images> al_menu,int int_position) {
        super(context, R.layout.adapter_photosfolder, al_menu);
        this.al_menu = al_menu;
        this.context = context;
        this.int_position = int_position;


    }

    @Override
    public int getCount() {

        Log.e("ADAPTER LIST SIZE", al_menu.get(int_position).getAl_imagepath().size() + "");
        return al_menu.get(int_position).getAl_imagepath().size();
    }

    @Override
    public int getItemViewType(int position) {
        return position;
    }

    @Override
    public int getViewTypeCount() {
        if (al_menu.get(int_position).getAl_imagepath().size() > 0) {
            return al_menu.get(int_position).getAl_imagepath().size();
        } else {
            return 1;
        }
    }

    @Override
    public long getItemId(int position) {
        return position;
    }


    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {

        if (convertView == null) {

            viewHolder = new ViewHolder();
            convertView = LayoutInflater.from(getContext()).inflate(R.layout.adapter_photosfolder, parent, false);
            viewHolder.tv_foldern = (TextView) convertView.findViewById(R.id.tv_folder);
            viewHolder.tv_foldersize = (TextView) convertView.findViewById(R.id.tv_folder2);
            viewHolder.iv_image = (ImageView) convertView.findViewById(R.id.iv_image);


            convertView.setTag(viewHolder);
        } else {
            viewHolder = (ViewHolder) convertView.getTag();
        }

        viewHolder.tv_foldern.setVisibility(View.GONE);
        viewHolder.tv_foldersize.setVisibility(View.GONE);



        Glide.with(context).load("file://" + al_menu.get(int_position).getAl_imagepath().get(position))
                .diskCacheStrategy(DiskCacheStrategy.NONE)
                .skipMemoryCache(true)
                .into(viewHolder.iv_image);


        return convertView;

    }

    private static class ViewHolder {
        TextView tv_foldern, tv_foldersize;
        ImageView iv_image;


    }


    }

模型图像.java

  package galleryimages.galleryimages;

    import java.util.ArrayList;

    public class Model_images {
    String str_folder;
    ArrayList<String> al_imagepath;

    public String getStr_folder() {
        return str_folder;
    }

    public void setStr_folder(String str_folder) {
        this.str_folder = str_folder;
    }

    public ArrayList<String> getAl_imagepath() {
        return al_imagepath;
    }

    public void setAl_imagepath(ArrayList<String> al_imagepath) {
        this.al_imagepath = al_imagepath;
    }
}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="galleryimages.galleryimages">

    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"></uses-permission>
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <activity android:name=".PhotosActivity"></activity>
    </application>

</manifest>
于 2017-03-20T08:23:24.550 回答
1

这就是我在 Kotlin 中使用 Coroutines 和 Flow 的方式（但 Flow 可以很容易地更改为 LivaData）。

依赖项：

def lifecycle_version = "2.2.0"
def coroutines_version = "1.4.2"
def glide_version = "4.11.0"

// Coroutines https://github.com/Kotlin/kotlinx.coroutines
implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core:$coroutines_version"
implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:$coroutines_version"

// Lifecycle https://developer.android.com/jetpack/androidx/releases/lifecycle#declaring_dependencies
implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:$lifecycle_version"

// Glide https://github.com/bumptech/glide (OPTIONALLY)
implementation "com.github.bumptech.glide:glide:$glide_version"

视图模型：

import android.app.Application
import android.content.ContentUris
import android.net.Uri
import android.provider.MediaStore
import androidx.lifecycle.AndroidViewModel
import androidx.lifecycle.viewModelScope
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.flow.MutableStateFlow
import kotlinx.coroutines.flow.StateFlow
import kotlinx.coroutines.launch
import kotlinx.coroutines.withContext

class AddViewModel(
    application: Application
) : AndroidViewModel(application)
{
    private val _allImagesFromGallery: MutableStateFlow<List<Uri>> = MutableStateFlow(listOf())
    val allImagesFromGallery: StateFlow<List<Uri>> = _allImagesFromGallery

    private fun getAllImages(): List<Uri>
    {
        val allImages = mutableListOf<Uri>()

        val imageProjection = arrayOf(
            MediaStore.Images.Media._ID
        )

        val imageSortOrder = "${MediaStore.Images.Media.DATE_ADDED} DESC"

        val cursor = getApplication<Application>().contentResolver.query(
            MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
            imageProjection,
            null,
            null,
            imageSortOrder
        )

        cursor.use {

            if (cursor != null)
            {
                val idColumn = cursor.getColumnIndexOrThrow(MediaStore.Images.Media._ID)
                while (cursor.moveToNext())
                {
                    allImages.add(
                        ContentUris.withAppendedId(
                            MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
                            cursor.getLong(idColumn)
                        )
                    )
                }
            }
            else
            {
                Log.d("AddViewModel", "Cursor is null!")
            }
        }
        return allImages
    }

    fun loadAllImages()
    {
        viewModelScope.launch {
            _allImagesFromGallery.value = withContext(Dispatchers.IO) {
                getAllImages()
            }
        }
    }
}

在片段（或活动）中：

import android.os.Bundle
import android.view.View
import androidx.databinding.DataBindingUtil
import androidx.fragment.app.Fragment
import androidx.fragment.app.activityViewModels
import androidx.lifecycle.lifecycleScope
import com.bumptech.glide.Glide
import kotlinx.coroutines.flow.collectLatest

class AddFragment : Fragment(R.layout.fragment_add)
{
    private lateinit var binding: FragmentAddBinding
    private val viewModel: AddViewModel by activityViewModels()

    override fun onViewCreated(view: View, savedInstanceState: Bundle?)
    {
        super.onViewCreated(view, savedInstanceState)
        binding = DataBindingUtil.bind(view)!!

        viewModel.loadAllImages()
        setupCollecting()
    }

    private fun setupCollecting()
    {
        lifecycleScope.launchWhenStarted {
            viewModel.allImagesFromGallery.collectLatest {
                // simple test, take first image and load it to ImageView using Glide
                if (it.isNotEmpty())
                {
                    Glide.with(requireContext())
                        .load(it[0])
                        .into(binding.imgSelected)
                }
            }
        }
    }
}

  1. 在从图库Manifest.permission.READ_EXTERNAL_STORAGE中加载所有图像之前，必须获得授权。

  2. 在 Manifest 中使用Glide时，还应该有：android:requestLegacyExternalStorage="true"

于 2021-01-12T17:43:18.160 回答