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社区首页 >问答首页 >如何解决: java.lang.ClassCastException: android.graphics.Bitmap不能转换为android.net.Uri

问如何解决: java.lang.ClassCastException: android.graphics.Bitmap不能转换为android.net.Uri
EN

Stack Overflow用户
提问于 2013-11-23 07:27:10
回答 2查看 5.5K关注 0票数 1

当我有时间在什么应用上分享图片的时候，facebook等等。它的文件、读取和抛出失败的原因是：

代码语言：javascript
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java.lang.ClassCastException: android.graphics.Bitmap cannot be cast to android.net.Uri
11-23 12:32:02.835: E/AndroidRuntime(11662):         at com.whatsapp.ContactPicker.d(ContactPicker.java:531)
11-23 12:32:02.835: E/AndroidRuntime(11662):         at com.whatsapp.ContactPicker.onCreate(ContactPicker.java:306)
11-23 12:32:02.835: E/AndroidRuntime(11662):         at android.app.Activity.performCreate(Activity.java:4479)
11-23 12:32:02.835: E/AndroidRuntime(11662):         at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1050)
11-23 12:32:02.835: E/AndroidRuntime(11662):         at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2041)

我的活动：

代码语言：javascript
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public class FullImageActivity extends Activity {
    ImageView imageView;
    Button buttonsetwallpaper, share;
    String sp_items[] = new String[] { "Setwallpaper", "Share", "Exit" };
    Spinner spinner;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.full_image);
        buttonsetwallpaper = (Button) findViewById(R.id.wallpaper);
        buttonsetwallpaper.getBackground().setColorFilter(0xFF00FF00,
                PorterDuff.Mode.MULTIPLY);
        share = (Button) findViewById(R.id.button2);
        // get intent data
        Intent i = getIntent();
        final int position = i.getExtras().getInt("id");
        final ImageAdapter imageAdapter = new ImageAdapter(this);

        imageView = (ImageView) findViewById(R.id.full_image_view);
        imageView.setImageResource(imageAdapter.mThumbIds[position]);

        share.setOnClickListener(new Button.OnClickListener() {
            @Override
            public void onClick(View arg0) {

                // Bitmap o = BitmapFactory.decodeFile("/sdcard/." + img_name);
                // Bitmap o =
                // BitmapFactory.decodeFile(Environment.getExternalStorageDirectory().getAbsolutePath()+"/wallpaperapp/");
                Bitmap mBitmap = BitmapFactory.decodeResource(getResources(),
                        imageAdapter.mThumbIds[position]);
                // Bitmap mBitmap =
                // BitmapFactory.decodeResource(getResources(),(int)i.getItemId(position));
                try {

                    Intent share = new Intent(Intent.ACTION_SEND);
                    share.setType("image/png");
                    System.out.println("*********************" + mBitmap);
                    share.putExtra(
                            Intent.EXTRA_STREAM,
                            scaleDownBitmap(mBitmap, 90, FullImageActivity.this));
                    startActivity(Intent.createChooser(share, "Share Image"));
                } catch (Exception e) {
                    e.printStackTrace();
                    // Toast.makeText(FullImageActivity.this,
                    // "Error setting wallpaper", Toast.LENGTH_SHORT).show();
                }
            }
        });

        buttonsetwallpaper.setOnClickListener(new Button.OnClickListener() {
            @Override
            public void onClick(View arg0) {

                // Bitmap o = BitmapFactory.decodeFile("/sdcard/." + img_name);
                // Bitmap o =
                // BitmapFactory.decodeFile(Environment.getExternalStorageDirectory().getAbsolutePath()+"/wallpaperapp/");
                Bitmap mBitmap = BitmapFactory.decodeResource(getResources(),
                        imageAdapter.mThumbIds[position]);
                // Bitmap mBitmap =
                // BitmapFactory.decodeResource(getResources(),(int)i.getItemId(position));

                WallpaperManager myWallpaperManager = WallpaperManager
                        .getInstance(getApplicationContext());

                try {
                    myWallpaperManager.setBitmap(mBitmap);
                    Toast.makeText(FullImageActivity.this, "Wallpaper set",
                            Toast.LENGTH_SHORT).show();
                } catch (IOException e) {
                    Toast.makeText(FullImageActivity.this,
                            "Error setting wallpaper", Toast.LENGTH_SHORT)
                            .show();
                }
            }
        });
    }

    Bitmap scaleDownBitmap(Bitmap photo, int newHeight, Context context) {

        final float densityMultiplier = context.getResources()
                .getDisplayMetrics().density;

        int h = (int) (newHeight * densityMultiplier);
        int w = (int) (h * photo.getWidth() / ((double) photo.getHeight()));

        photo = Bitmap.createScaledBitmap(photo, w, h, true);

        return photo;
    }

我的图片在布局文件夹与保存到sdcard，我想在这里分享，我给我的代码plz帮助我。

代码语言：javascript
运行
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public class ImageAdapter extends BaseAdapter {
private Context mContext;
ImageView imageView;
// Keep all Images in array
public Integer[] mThumbIds = { R.drawable.a1, R.drawable.a2, R.drawable.a3,
        R.drawable.a10, R.drawable.a11, R.drawable.a12, R.drawable.a13,
        R.drawable.a14, R.drawable.a15, R.drawable.a16, R.drawable.a17,
        R.drawable.a18, R.drawable.a19, R.drawable.a20, R.drawable.a21,

        R.drawable.a22, R.drawable.a23, R.drawable.a24, R.drawable.a25,
        R.drawable.a26, R.drawable.a27, R.drawable.a28, R.drawable.a30,
        R.drawable.a31, R.drawable.a32, R.drawable.a33, R.drawable.a34,
        R.drawable.a35, R.drawable.a36, R.drawable.a37,

        R.drawable.a38, R.drawable.a39, R.drawable.a4, R.drawable.a40,
        R.drawable.a41, R.drawable.a42, R.drawable.a43, R.drawable.a5,
        R.drawable.a6, R.drawable.a7, R.drawable.a8, R.drawable.a9,
        R.drawable.aa9

};

// Constructor
public ImageAdapter(Context c) {
    mContext = c;
}

@Override
public int getCount() {
    return mThumbIds.length;
}

@Override
public Object getItem(int position) {
    return mThumbIds[position];
}

@Override
public long getItemId(int position) {
    return 0;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    ImageView imageView = new ImageView(mContext);

    if (convertView == null) {
        imageView = new ImageView(mContext);
        imageView.setLayoutParams(new GridView.LayoutParams(250, 300));
        imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
        imageView.setPadding(4, 4, 4, 4);
    } else {
        imageView = (ImageView) convertView;
    }

    imageView.setImageResource(mThumbIds[position]);

    return imageView;
}

}

intentservice
android
bitmap
EN

回答 2

Stack Overflow用户

发布于 2013-11-23 07:32:32

在这一行中，您必须传递保存的映像uri，而不是Bitamp。

代码语言：javascript
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 share.putExtra(Intent.EXTRA_STREAM,
                    scaleDownBitmap(mBitmap, 90, FullImageActivity.this));

像这样改变..。

代码语言：javascript
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Bitmap icon=scaleDownBitmap(mBitmap, 90, FullImageActivity.this);
ByteArrayOutputStream bytes = new ByteArrayOutputStream();
icon.compress(Bitmap.CompressFormat.JPEG, 100, bytes);
File f = new File(Environment.getExternalStorageDirectory() + File.separator + "temporary_file.jpg");
try {
    f.createNewFile();
    FileOutputStream fo = new FileOutputStream(f);
    fo.write(bytes.toByteArray());
} catch (IOException e) {                       
        e.printStackTrace();
}
share.putExtra(Intent.EXTRA_STREAM, Uri.parse("file:///sdcard/temporary_file.jpg")

screenshotUri是图像的Uri路径。

另一种方式是..。

代码语言：javascript
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Bitmap icon=scaleDownBitmap(mBitmap, 90, FullImageActivity.this);
ByteArrayOutputStream bytes = new ByteArrayOutputStream();
icon.compress(Bitmap.CompressFormat.JPEG, 100, bytes);
share.putExtra(Intent.EXTRA_STREAM, bytes.toByteArray());
票数 2
EN

Stack Overflow用户

发布于 2013-11-23 07:40:10

在单击侦听器的share中，您在下面写了这一行，这一行是错误:-

代码语言：javascript
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share.putExtra(Intent.EXTRA_STREAM,scaleDownBitmap(mBitmap, 90, FullImageActivity.this));

在这种情况下，您将调用返回位图的scaleDownBtmap函数。现在，inten.putExtra方法不使用位图参数，这就是为什么要获得类强制转换异常。您需要在字节流中转换位图，然后在put额外方法中传递它。位图scaleDownBitmap(位图照片，int newHeight，上下文上下文){

代码语言：javascript
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final float densityMultiplier = context.getResources()
        .getDisplayMetrics().density;

int h = (int) (newHeight * densityMultiplier);
int w = (int) (h * photo.getWidth() / ((double) photo.getHeight()));

photo = Bitmap.createScaledBitmap(photo, w, h, true);

return photo;

}

putExtra方法不使用位图参数。这样做:-

代码语言：javascript
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Bitmap b = scaleDownBitmap(mBitmap, 90, FullImageActivity.this); // your bitmap // use your scaleDownBitmap ere
ByteArrayOutputStream bs = new ByteArrayOutputStream();
b.compress(Bitmap.CompressFormat.PNG, 50, bs);
share.putExtra("byteArray", bs.toByteArray());

然后在接收活动中，将这个字节流转换为一个位图:-

代码语言：javascript
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Bitmap b = BitmapFactory.decodeByteArray(
    getIntent().getByteArrayExtra("byteArray"),0,getIntent().getByteArrayExtra("byteArray").length);
票数 0
EN
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：

https://stackoverflow.com/questions/20159785

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