android - 写app截屏，然后保存到我安卓手机的相册里，但是保存的截图是全黑的

Question

这是我的屏幕截图类。该应用程序正在将屏幕截图保存在我的画廊中，这正是我想要的，但图像是全黑的!如果您对这项工作有任何建议，我们将不胜感激!谢谢!

public class Screenshot extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

          // set event listener for the Save Contact Button
          Button button = 
             (Button) findViewById(R.id.button);
          button.setOnClickListener(buttonClicked);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.screenshot, menu);
        return true;
    }

       // responds to event generated when user clicks the Done Button
       OnClickListener buttonClicked = new OnClickListener() 
       {
          @Override
          public void onClick(View v) 
          {
              Bitmap bitmap = takeScreenshot();
              saveBitmap(bitmap);
           }         
       };


     public void saveBitmap(Bitmap bitmap) {
         LinearLayout mainLayout = (LinearLayout) findViewById(R.id.LinearLayout01);
         Bitmap b = Bitmap.createBitmap(mainLayout.getWidth(), mainLayout.getHeight(), 
                 Bitmap.Config.ARGB_8888);
         MediaStore.Images.Media.insertImage(getContentResolver(), b, "image.png" , "screenshot");
    }

    public Bitmap takeScreenshot() {
         View rootView = findViewById(android.R.id.content).getRootView();
         rootView.setDrawingCacheEnabled(true);
        return rootView.getDrawingCache();
        }
}

这是我的 main.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="@+id/LinearLayout01"
>
<Button
android:id="@+id/button"
android:layout_height = "wrap_content"
android:layout_width ="wrap_content"
android:text = "take screenshot"
android:onClick = "DoIt"
/>

<ImageView
android:id="@+id/eiffelTowerImageView"
android:layout_width="200dip"
android:layout_height="200dip"
android:layout_toRightOf="@+id/colosseumImageView"
android:src="@drawable/eiffeltower" />
</LinearLayout>

Answer 1

这段代码对我来说就像一个魅力

private static Bitmap takeScreenShot(Activity activity) {
    View view = activity.getWindow().getDecorView();
    view.setDrawingCacheEnabled(true);
    view.buildDrawingCache();
    Bitmap b1 = view.getDrawingCache();
    Rect frame = new Rect();
    activity.getWindow().getDecorView().getWindowVisibleDisplayFrame(frame);
    int statusBarHeight = frame.top;
    int width = activity.getWindowManager().getDefaultDisplay().getWidth();
    int height = activity.getWindowManager().getDefaultDisplay()
            .getHeight();

    Bitmap b = Bitmap.createBitmap(b1, 0, statusBarHeight, width, height
            - statusBarHeight);
    view.destroyDrawingCache();
    Log.e("Screenshot", "taken successfully");
    return b;

}

public void saveBitmap(Bitmap bitmap) {
    File imagePath = new File(Environment.getExternalStorageDirectory()
            + "/screenshot.png");
    FileOutputStream fos;
    try {
        fos = new FileOutputStream(imagePath);
        bitmap.compress(CompressFormat.JPEG, 100, fos);
        Log.e("Screenshot", "saved successfully");

        fos.flush();
        fos.close();
    } catch (FileNotFoundException e) {
        Log.e("GREC", e.getMessage(), e);
    } catch (IOException e) {
        Log.e("GREC", e.getMessage(), e);
    }

}

在 OnCreate() 中获取 Activity

Activity activity = (MainActivity) this;

然后在任何你想要的地方调用这些函数

Bitmap bitmap = takeScreenShot(activity);
saveBitmap(bitmap);