56

我正在尝试将相册中的照片添加到 aImageView但我收到此错误：

java.lang.RuntimeException：将结果 ResultInfo{who=null, request=1, result=-1, data=Intent { dat=content://media/external/images/media/1 }} 传递给活动 {hotMetter.包/hotMetter.pack.GetPhoto}：java.lang.NullPointerException

这是我的代码：

      Intent intent = new Intent();
      intent.setType("image/*");
      intent.setAction(Intent.ACTION_GET_CONTENT);

      startActivityForResult(Intent.createChooser(intent,"Select Picture"), SELECT_PICTURE);
}
Bitmap bitmap=null;
public void onActivityResult(int requestCode, int resultCode, Intent data)
{

    if (resultCode == Activity.RESULT_OK)
    {
        if (requestCode == SELECT_PICTURE) 
        {
             Uri selectedImageUri = data.getData();           
             selectedImagePath = getPath(selectedImageUri);             
             tv.setText(selectedImagePath);
             img.setImageURI(selectedImageUri); 
         }
    }


 public String getPath(Uri uri) 
    {
        String[] projection = { MediaStore.Images.Media.DATA };
        Cursor cursor = managedQuery(uri, projection, null, null, null);
        if (cursor == null) return null;
        int column_index =             cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
        cursor.moveToFirst();
        String s=cursor.getString(column_index);
        cursor.close();
        return s;
    }

我得到了selectedImagePath="mnt/sdcard/DCIM/myimage"但是img.setImageURI(selectedImageUri);我得到了错误。

我也使用了 aBitmap并尝试设置图像，SetImageBitmap但我得到了同样的错误。

日志猫：

05-06 19:41:34.191: E/AndroidRuntime(8466): java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=1, result=-1, data=Intent { dat=content://media/external/images/media/1 }} to activity {hotMetter.pack/hotMetter.pack.GetPhoto}: java.lang.NullPointerException
05-06 19:41:34.191: E/AndroidRuntime(8466):     at android.app.ActivityThread.deliverResults(ActivityThread.java:2532)
05-06 19:41:34.191: E/AndroidRuntime(8466):     at android.app.ActivityThread.handleSendResult(ActivityThread.java:2574)
05-06 19:41:34.191: E/AndroidRuntime(8466):     at android.app.ActivityThread.access$2000(ActivityThread.java:117)
05-06 19:41:34.191: E/AndroidRuntime(8466):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:961)
05-06 19:41:34.191: E/AndroidRuntime(8466):     at android.os.Handler.dispatchMessage(Handler.java:99)
05-06 19:41:34.191: E/AndroidRuntime(8466):     at android.os.Looper.loop(Looper.java:123)
05-06 19:41:34.191: E/AndroidRuntime(8466):     at android.app.ActivityThread.main(ActivityThread.java:3683)
05-06 19:41:34.191: E/AndroidRuntime(8466):     at java.lang.reflect.Method.invokeNative(Native Method)
05-06 19:41:34.191: E/AndroidRuntime(8466):     at java.lang.reflect.Method.invoke(Method.java:507)
05-06 19:41:34.191: E/AndroidRuntime(8466):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
05-06 19:41:34.191: E/AndroidRuntime(8466):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
05-06 19:41:34.191: E/AndroidRuntime(8466):     at dalvik.system.NativeStart.main(Native Method)
05-06 19:41:34.191: E/AndroidRuntime(8466): Caused by: java.lang.NullPointerException
05-06 19:41:34.191: E/AndroidRuntime(8466):     at hotMetter.pack.GetPhoto.onActivityResult(GetPhoto.java:55)
05-06 19:41:34.191: E/AndroidRuntime(8466):     at android.app.Activity.dispatchActivityResult(Activity.java:3908)
05-06 19:41:34.191: E/AndroidRuntime(8466):     at android.app.ActivityThread.deliverResults(ActivityThread.java:2528)

请提供建议。谢谢！

4

13 回答 13

113

先简单通过Intent：

Intent i = new Intent(Intent.ACTION_PICK,android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(i, RESULT_LOAD_IMAGE);

你会得到你的图片路径onActivityResult：

@Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == RESULT_LOAD_IMAGE && resultCode == RESULT_OK && null != data) {
            Uri selectedImage = data.getData();
            String[] filePathColumn = { MediaStore.Images.Media.DATA };
            Cursor cursor = getContentResolver().query(selectedImage,filePathColumn, null, null, null);
            cursor.moveToFirst();
            int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
            String picturePath = cursor.getString(columnIndex);
            cursor.close();
            ImageView imageView = (ImageView) findViewById(R.id.imgView);
            imageView.setImageBitmap(BitmapFactory.decodeFile(picturePath));
        }
    }

完整的源代码在这里

于 2012-05-06T20:47:57.573 回答
16

@parag 的代码效果很好。但是在加载一些大图像时，您可能会失败。你应该使用；

imageView.setImageBitmap(getScaledBitmap(picturePath, 800, 800));

代替; 

imageView.setImageBitmap(BitmapFactory.decodeFile(picturePath));

这是我可以使用的方法。

private Bitmap getScaledBitmap(String picturePath, int width, int height) {
    BitmapFactory.Options sizeOptions = new BitmapFactory.Options();
    sizeOptions.inJustDecodeBounds = true;
    BitmapFactory.decodeFile(picturePath, sizeOptions);

    int inSampleSize = calculateInSampleSize(sizeOptions, width, height);

    sizeOptions.inJustDecodeBounds = false;
    sizeOptions.inSampleSize = inSampleSize;

    return BitmapFactory.decodeFile(picturePath, sizeOptions);
}

private int calculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight) {
    // Raw height and width of image
    final int height = options.outHeight;
    final int width = options.outWidth;
    int inSampleSize = 1;

    if (height > reqHeight || width > reqWidth) {

        // Calculate ratios of height and width to requested height and
        // width
        final int heightRatio = Math.round((float) height / (float) reqHeight);
        final int widthRatio = Math.round((float) width / (float) reqWidth);

        // Choose the smallest ratio as inSampleSize value, this will
        // guarantee
        // a final image with both dimensions larger than or equal to the
        // requested height and width.
        inSampleSize = heightRatio < widthRatio ? heightRatio : widthRatio;
    }

    return inSampleSize;
}
于 2013-07-08T17:53:47.427 回答
11

这是从图库中获取图像并进行裁剪的最简单方法

第 1 步：结果的 StartActivity

imageUser.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            Intent intent = new Intent(Intent.ACTION_PICK,
                    MediaStore.Images.Media.INTERNAL_CONTENT_URI);
            intent.setType("image/*");
            intent.putExtra("crop", "true");
            intent.putExtra("scale", true);
            intent.putExtra("outputX", 256);
            intent.putExtra("outputY", 256);
            intent.putExtra("aspectX", 1);
            intent.putExtra("aspectY", 1);
            intent.putExtra("return-data", true);
            startActivityForResult(intent, 1);

            }
    });

第二步：处理结果

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if (resultCode != RESULT_OK) {
        return;
    }
    if (requestCode == 1) {
        final Bundle extras = data.getExtras();
        if (extras != null) {
            //Get image
            Bitmap ProfilePic = extras.getParcelable("data");
            imageUser.setImageBitmap(ProfilePic);
            TextView t=(TextView)findViewById(R.id.textoverimage);
            t.setText("image Selected");
        }
    }


}
于 2016-06-22T11:18:43.047 回答
8

在调试模式下运行应用程序并在 if 上设置断点，(requestCode == SELECT_PICTURE)并在您逐步执行时检查每个变量，以确保它按预期设置。如果您正在获得 NPE，img.setImageURI(selectedImageUri);则要么未设置，img要么selectedImageUri未设置。

于 2012-05-06T20:38:09.097 回答
3 
import android.content.Intent;
import android.net.Uri;
import android.provider.MediaStore;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.ImageView;

public class MainActivity extends AppCompatActivity {

    ImageView img;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        img = (ImageView)findViewById(R.id.imageView);
    }

    public void btn_gallery(View view) {

        Intent intent =new Intent(Intent.ACTION_PICK, MediaStore.Images.Media.INTERNAL_CONTENT_URI);

        startActivityForResult(intent,100);
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        if (requestCode==100 && resultCode==RESULT_OK)
        {
            Uri uri = data.getData();
            img.setImageURI(uri);
        }
    }
}
于 2017-12-15T18:42:33.410 回答
2

我认为最简单的方法是使用库 ContentManager。这个库用于从设备库、云或相机中获取照片或视频。使用来自云端的异步加载并修复了一些问题设备的错误。

通过 Gradle 下载： 您可以在https://github.com/stfalcon-studio/ContentManager compile 'com.github.stfalcon:contentmanager:0.4.3' 找到文档

于 2017-02-24T12:12:44.327 回答
1

我认为你的 ImageView img 没有实例化它等于 null 给编译器；这就是引发 NullPointerException 的原因

你有没有打电话给你的活动

img = (ImageView) findViewById(R.id.my_imageview);

其中 my_imageview 是您的 ImageView 小部件的 ID！

于 2012-05-07T00:08:50.913 回答
1

@Parag Chauhan 解决方案运行良好，但我遇到了问题 - 一些文件管理器应用程序返回 Intent 对象“file:///...”而不是“content://...” - 这是使用查询所必需的.

对于这个问题，我有一个简短的解决方案：

public String getRealPathFromURI(Context context, Uri contentUri) {
    Cursor cursor = null;
    try {

        if("content".equals(contentUri.getScheme())) {
            String[] proj = {MediaStore.Images.Media.DATA};
            cursor = context.getContentResolver().query(contentUri, proj, null, null, null);
            int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
            cursor.moveToFirst();
            return cursor.getString(column_index);
        }
        else{
            return contentUri.getPath();
        }


    } finally {
        if (cursor != null) {
            cursor.close();
        }
    }
}

基于@Parag 解决方案，

部分解决方案 (@nobre) Android：从内容 URI 获取文件 URI？

此处的部分解决方案（@Nikolay）从媒体存储的 URI 获取文件名和路径

于 2014-07-22T10:26:51.793 回答
1

最初的答案是你的路径必须加入像 Uri.parse("file://" + file.getPath); 这样的前缀。

于 2015-08-21T12:38:32.973 回答
1

这是对我有用的代码。

Button buttonLoadImage = (Button) findViewById(R.id.button4);
    buttonLoadImage.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Intent intent = new Intent(Intent.ACTION_PICK,
                    MediaStore.Images.Media.INTERNAL_CONTENT_URI);
            intent.setType("image/*");
            intent.putExtra("crop", "true");
            intent.putExtra("scale", true);
            intent.putExtra("outputX", 256);
            intent.putExtra("outputY", 256);
            intent.putExtra("aspectX", 1);
            intent.putExtra("aspectY", 1);
            intent.putExtra("return-data", true);
            startActivityForResult(intent, 1);}});
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if (resultCode != RESULT_OK) {

        if (requestCode == RESULT_LOAD_IMAGE && data != null) {
            Uri imageUri = data.getData();
            imageView = (ImageView) findViewById(R.id.imgView);
            imageView.setImageURI(imageUri);}}}

在清单文件中添加

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
于 2017-01-12T05:12:57.077 回答
1

将以下代码放入按钮单击事件中

Intent ImageIntent = new Intent(Intent.ACTION_PICK,               
MediaStore.Images.Media.EXTERNAL_CONTENT_URI); //implicit intent
UploadImage.this.startActivityForResult(ImageIntent,99);

将下面的代码放在 startActivityforResult 事件中

Uri ImagePathAndName = data.getData();
imgpicture.setImageURI(ImagePathAndName);
于 2017-01-30T23:45:11.107 回答
0

parag-chauhan和devrim的答案是完美的，但我在没有光标的情况下更改了 onActivityResult，它使代码变得更好。

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);

    if (requestCode == RESULT_LOAD_IMAGE && resultCode == RESULT_OK && data != null) {
        Uri selectedImage = data.getData();
        try {
           ImageView imageView = (ImageView) findViewById(R.id.imgView);
           imageView.setImageBitmap(getScaledBitmap(selectedImage,800,800));
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
    }
}

private Bitmap getScaledBitmap(Uri selectedImage, int width, int height) throws FileNotFoundException {
    BitmapFactory.Options sizeOptions = new BitmapFactory.Options();
    sizeOptions.inJustDecodeBounds = true;
    BitmapFactory.decodeStream(getContentResolver().openInputStream(selectedImage), null, sizeOptions);

    int inSampleSize = calculateInSampleSize(sizeOptions, width, height);

    sizeOptions.inJustDecodeBounds = false;
    sizeOptions.inSampleSize = inSampleSize;

    return BitmapFactory.decodeStream(getContentResolver().openInputStream(selectedImage), null, sizeOptions);
}

private int calculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight) {
    // Raw height and width of image
    final int height = options.outHeight;
    final int width = options.outWidth;
    int inSampleSize = 1;

    if (height > reqHeight || width > reqWidth) {
        // Calculate ratios of height and width to requested one
        final int heightRatio = Math.round((float) height / (float) reqHeight);
        final int widthRatio = Math.round((float) width / (float) reqWidth);

        // Choose the smallest ratio as inSampleSize value
        inSampleSize = heightRatio < widthRatio ? heightRatio : widthRatio;
    }
    return inSampleSize;
}
于 2017-09-12T05:25:41.943 回答
0 
//try this to pick image from gallery..
    public void gotogallery(View view) { 
// onclick for gallery button
        chooseImage();
    }
// choose image from gallery
          public void chooseImage() {
        Intent intent = new Intent();
        intent.setType("image/*");
        intent.setAction(Intent.ACTION_GET_CONTENT);
        startActivityForResult(Intent.createChooser(intent, "Select Picture"), PICK_IMAGE_REQUEST); //activity result method call
    }

    @Override
    protected void onActivityResult(int requestcode,int resultcode,Intent data ) {
        super.onActivityResult(requestcode, resultcode, data);

        if (requestcode == PICK_IMAGE_REQUEST && resultcode == RESULT_OK && data != null && data.getData() != null) {

            Uri uri = data.getData();

            try {
           Bitmap bitmap = MediaStore.Images.Media.getBitmap(getContentResolver(), uri);


                slectimageview=findViewById(R.id.imageviewimagetopdf_id);
                slectimageview.setImageBitmap(bitmap);


            } catch (IOException e) {
                e.printStackTrace();
            }
        }


    }
于 2020-09-18T12:38:38.007 回答