1

大家好,我已经厌倦了使用位图功能,我可以获取图像,但我只能在网格视图中显示它们。我想用幻灯片在图像视图中显示它们。请让我知道我是否可以用位图做到这一点。这是我的应用程序的代码,它位于ScrollView.

package com.example.sdcardimagessync;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.ArrayList;

import android.app.Activity;
import android.content.Context;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.provider.MediaStore;
import android.view.Display;
import android.view.View;
import android.view.ViewGroup;
import android.view.Window;
import android.view.WindowManager;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;
import android.widget.AdapterView.OnItemClickListener;

public class MainActivity extends Activity implements OnItemClickListener {

    /**
     * Grid view holding the images.
     */
    private GridView sdcardImages;
    /**
     * Image adapter for the grid view.
     */
    private ImageAdapter imageAdapter;
    /**
     * Display used for getting the width of the screen.
     */
    private Display display;

    /**
     * Creates the content view, sets up the grid, the adapter, and the click
     * listener.
     * 
     * @see android.app.Activity#onCreate(android.os.Bundle)
     */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // Request progress bar
        requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
        setContentView(R.layout.activity_main);

        display = ((WindowManager) getSystemService(Context.WINDOW_SERVICE))
                .getDefaultDisplay();

        setupViews();
        setProgressBarIndeterminateVisibility(true);
        loadImages();
    }

    /**
     * Free up bitmap related resources.
     */
    protected void onDestroy() {
        super.onDestroy();
        final GridView grid = sdcardImages;
        final int count = grid.getChildCount();
        ImageView v = null;
        for (int i = 0; i < count; i++) {
            v = (ImageView) grid.getChildAt(i);
            ((BitmapDrawable) v.getDrawable()).setCallback(null);
        }
    }

    /**
     * Setup the grid view.
     */
    private void setupViews() {
        sdcardImages = (GridView) findViewById(R.id.GridView1);
        sdcardImages.setNumColumns(display.getWidth() / 1000);
        sdcardImages.setClipToPadding(false);
        sdcardImages.setOnItemClickListener(MainActivity.this);
        imageAdapter = new ImageAdapter(getApplicationContext());
        sdcardImages.setAdapter(imageAdapter);
    }

    /**
     * Load images.
     */
    private void loadImages() {
        final Object data = getLastNonConfigurationInstance();
        if (data == null) {
            new LoadImagesFromSDCard().execute();
        } else {
            final LoadedImage[] photos = (LoadedImage[]) data;
            if (photos.length == 0) {
                new LoadImagesFromSDCard().execute();
            }
            for (LoadedImage photo : photos) {
                addImage(photo);
            }
        }
    }

    /**
     * Add image(s) to the grid view adapter.
     * 
     * @param value
     *            Array of LoadedImages references
     */
    private void addImage(LoadedImage... value) {
        for (LoadedImage image : value) {
            imageAdapter.addPhoto(image);
            imageAdapter.notifyDataSetChanged();
        }
    }

    /**
     * Save bitmap images into a list and return that list.
     * 
     * @see android.app.Activity#onRetainNonConfigurationInstance()
     */
    @Override
    public Object onRetainNonConfigurationInstance() {
        final GridView grid = sdcardImages;
        final int count = grid.getChildCount();
        final LoadedImage[] list = new LoadedImage[count];

        for (int i = 0; i < count; i++) {
            final ImageView v = (ImageView) grid.getChildAt(i);
            list[i] = new LoadedImage(
                    ((BitmapDrawable) v.getDrawable()).getBitmap());
        }

        return list;
    }

    /**
     * Async task for loading the images from the SD card.
     * 
     * @author Mihai Fonoage
     * 
     */
    class LoadImagesFromSDCard extends AsyncTask<Object, LoadedImage, Object> {

        /**
         * Load images from SD Card in the background, and display each image on
         * the screen.
         * 
         * @see android.os.AsyncTask#doInBackground(Params[])
         */
        @Override
        protected Object doInBackground(Object... params) {
            // setProgressBarIndeterminateVisibility(true);
            Bitmap bitmap = null;
            Bitmap newBitmap = null;
            Uri uri = null;

            // Set up an array of the Thumbnail Image ID column we want
            String[] projection = { MediaStore.Images.Thumbnails._ID };
            // Create the cursor pointing to the SDCard
            Cursor cursor = managedQuery(
                    MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI,
                    projection, // Which columns to return
                    null, // Return all rows
                    null, null);
            int columnIndex = cursor
                    .getColumnIndexOrThrow(MediaStore.Images.Thumbnails._ID);
            int size = cursor.getCount();
            // If size is 0, there are no images on the SD Card.
            if (size == 0) {
                // No Images available, post some message to the user
            }
            int imageID = 0;
            for (int i = 0; i < size; i++) {
                cursor.moveToPosition(i);
                imageID = cursor.getInt(columnIndex);
                uri = Uri.withAppendedPath(
                        MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI, ""
                                + imageID);
                try {
                    bitmap = BitmapFactory.decodeStream(getContentResolver()
                            .openInputStream(uri));
                    if (bitmap != null) {
                        newBitmap = Bitmap.createScaledBitmap(bitmap, 500, 500,
                                true);
                        bitmap.recycle();
                        if (newBitmap != null) {
                            publishProgress(new LoadedImage(newBitmap));
                        }
                    }
                } catch (IOException e) {
                    // Error fetching image, try to recover
                }
            }
            cursor.close();
            return null;
        }

        /**
         * Add a new LoadedImage in the images grid.
         * 
         * @param value
         *            The image.
         */
        @Override
        public void onProgressUpdate(LoadedImage... value) {
            addImage(value);
        }

        /**
         * Set the visibility of the progress bar to false.
         * 
         * @see android.os.AsyncTask#onPostExecute(java.lang.Object)
         */
        @Override
        protected void onPostExecute(Object result) {
            setProgressBarIndeterminateVisibility(false);
        }
    }

    /**
     * Adapter for our image files.
     * 
     * @author Mihai Fonoage
     * 
     */
    class ImageAdapter extends BaseAdapter {

        private Context mContext;
        private ArrayList<LoadedImage> photos = new ArrayList<LoadedImage>();

        public ImageAdapter(Context context) {
            mContext = context;
        }

        public void addPhoto(LoadedImage photo) {
            photos.add(photo);
        }

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

        public Object getItem(int position) {
            return photos.get(position);
        }

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

        public View getView(int position, View convertView, ViewGroup parent) {
            final ImageView imageView;
            if (convertView == null) {
                imageView = new ImageView(mContext);
            } else {
                imageView = (ImageView) convertView;
            }
            imageView.setScaleType(ImageView.ScaleType.FIT_CENTER);
            imageView.setPadding(8, 8, 8, 8);
            imageView.setImageBitmap(photos.get(position).getBitmap());
            return imageView;
        }
    }

    /**
     * A LoadedImage contains the Bitmap loaded for the image.
     */
    private static class LoadedImage {
        Bitmap mBitmap;

        LoadedImage(Bitmap bitmap) {
            mBitmap = bitmap;
        }

        public Bitmap getBitmap() {
            return mBitmap;
        }
    }

    /**
     * When an image is clicked, load that image as a puzzle.
     */
    public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
        int columnIndex = 0;
        String[] projection = { MediaStore.Images.Media.DATA };
        Cursor cursor = managedQuery(
                MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI, projection,
                null, null, null);
        if (cursor != null) {
            columnIndex = cursor
                    .getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
            cursor.moveToPosition(position);
            String imagePath = cursor.getString(columnIndex);

            FileInputStream is = null;
            BufferedInputStream bis = null;
            try {
                is = new FileInputStream(new File(imagePath));
                bis = new BufferedInputStream(is);
                Bitmap bitmap = BitmapFactory.decodeStream(bis);
                Bitmap useThisBitmap = Bitmap.createScaledBitmap(bitmap,
                        parent.getWidth(), parent.getHeight(), true);
                bitmap.recycle();
                // Display bitmap (useThisBitmap)
            } catch (Exception e) {
                // Try to recover
            } finally {
                try {
                    if (bis != null) {
                        bis.close();
                    }
                    if (is != null) {
                        is.close();
                    }
                    cursor.close();
                    projection = null;
                } catch (Exception e) {
                }
            }
        }
    }
}
4

2 回答 2

1

您可以使用ViewFlipper。用 ImageViews 填充它并根据需要设置动画。

[编辑]

我不保证这会在没有一些调整的情况下工作,但沿着这些思路做的事情应该做你想要的。

所以,首先,将视图翻转器添加到 xml 布局中:

<ViewFlipper 
    android:id="@+id/image_flipper"
    android:layout_width="match_parent"
android:layout_height="match_parent" >
</ViewFlipper>

获取对视图翻转器的引用

ViewFlipper imageFlipper = (ViewFlipper)findViewById( R.id.image_flipper );

将图像视图添加到鳍状肢

for (LoadedImage photo : photos) {//or something like this
    ImageView image = new ImageView ( getApplicationContext() );
    image.setImageBitmap( photo.getBitmap() );
    imageFlipper.addView( image );
}

设置鳍状肢属性并开始

imageFlipper.setFlipInterval( 5000 ); //5s intervals
imageFlipper.startFlipping();
于 2012-08-17T19:25:10.563 回答
0

您可以将此Customizable SlideShow 组件用于 Android 平台。转到源代码并从那里获取下载源代码,它将对您的工作有很大帮助。

于 2012-08-18T11:47:57.977 回答