屏幕截图时黑色图像

Question

我想使用位图捕获我的Android屏幕，然后将其转换为图像。方法应该是静态的。

这是我的代码，我在其中单击按钮，然后单击" TakeCrernshot"时捕获TextureView并将其转换为位图，然后将其保存到File中。

。

public class MainActivity extends AppCompatActivity {
    //  View rootView = getWindow().getDecorView().getRootView();
    private static TextureView textureView;
    Button button;
    SurfaceView mPreview;
    private SurfaceHolder holder;
    private static File screenshotFile;
    private static float videoWidth = 1080.0f;
    private static float videoHeight = 1920.0f;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        textureView = (TextureView) findViewById(R.id.textureView);
        button = (Button) findViewById(R.id.button);
       // mPreview = (SurfaceView) findViewById(R.id.surface);
//        holder = mPreview.getHolder();
       // holder.setFormat(PixelFormat.RGBX_8888);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // takeScreenShot();
                takeScreenshotVideoPlaying();
            }
        });
    }

    public static Bitmap takeScreenshotVideoPlaying() {
        Log.d("", "takeScreenshotVideoPlaying() in VideoPlayerActivity running!");
        Bitmap bitmap = null;
        int tries = 100;
        for (int i = 1; i < tries; i++) {
            if (textureView.isAvailable()) {
                float bitmapScale = 4.0f;
                float bitmapWidth = videoWidth / bitmapScale;
                float bitmapHeight = videoHeight / bitmapScale;
                bitmap = textureView.getBitmap((int) bitmapWidth, (int) bitmapHeight);
                if (bitmap != null) {
                    Log.d("", "screenshot taken");
                    break;
                }
            }
        }
        saveScreenshot(bitmap);
        return bitmap;
    }

    private static void saveScreenshot(Bitmap bitmap) {
        ByteArrayOutputStream bytes = new ByteArrayOutputStream();
        Date now = new Date();
        android.text.format.DateFormat.format("yyyy-MM-dd_hh:mm:ss", now);

        String mPath = Environment.getExternalStorageDirectory().toString() + "/" + now + ".jpg";
        // see if this helps the uploading to GCS
        bitmap.compress(Bitmap.CompressFormat.JPEG, 100, bytes);
        screenshotFile = new File(mPath);
        try {
            if (screenshotFile.exists()) {
                screenshotFile.delete();
            }
            if (screenshotFile.createNewFile()) {
                FileOutputStream fo = new FileOutputStream(screenshotFile);
                fo.write(bytes.toByteArray());
                fo.close();
                Log.d("Saved", "saveScreenshot: ");
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

**and this is how layout looks like:**

我有一个纹理视图，我需要注册水龙头，并在将位图转换为文件后创建屏幕截图(仅用于测试( - 图像是黑色

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#534783"
    tools:context="com.maks.testscreenshots.MainActivity">

    <TextureView
        android:id="@+id/textureView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@android:color/holo_red_dark"/>
    <!--<SurfaceView-->
        <!--android:id="@+id/surface"-->
        <!--android:layout_width="wrap_content"-->
        <!--android:layout_height="wrap_content"-->
        <!--android:layout_gravity="center" />-->
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/button"
        android:text="Button"
        app:layout_constraintTop_toTopOf="parent"
        android:layout_marginTop="8dp"
        app:layout_constraintBottom_toBottomOf="parent"
        android:layout_marginBottom="8dp"
        android:layout_marginRight="8dp"
        app:layout_constraintRight_toRightOf="parent"
        android:layout_marginLeft="8dp"
        app:layout_constraintLeft_toLeftOf="parent" />
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World!"
        android:background="@color/colorAccent"
        android:textSize="100sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        android:id="@+id/textView" />
</android.support.constraint.ConstraintLayout>

Answer 1

问题是，我一直在试图屏幕截图textureView(渲染视频(，因此，当我尝试使用屏幕的getBitmap时，由于图像每次都会更改，因此我获得了黑屏。要捕获视频，我使用了2种不同的方法： - 对于扎根的设备，我用鼠标光标或屏幕上的其他任何内容捕获了整个屏幕：

 private static Bitmap takeScreenshot() {
        Bitmap screen;
        Bitmap resizedBitmap = null;
        try {
            Process sh = Runtime.getRuntime().exec("su", null, null);
            OutputStream os = sh.getOutputStream();
            Log.d("SCREENSHOT ", "PATH: " + ActFileUtil.getPathToScreenshotDirOnDevice());
            os.write(("/system/bin/screencap -p " + ActFileUtil.getPathToScreenshotDirOnDevice()).getBytes("ASCII"));
            os.flush();
            os.close();
            sh.waitFor();
            Log.d(TAG, "procScreenshot: SCREENSHOT TAKEN");
            screen = BitmapFactory.decodeFile(ActFileUtil.getPathToScreenshotDirOnDevice());
            if(screen != null) {
                resizedBitmap = Bitmap.createScaledBitmap(screen, screen.getWidth() / 4, screen.getHeight() / 4, true);
            }

        } catch (IOException | NullPointerException | InterruptedException e) {
            e.printStackTrace();
        }
        return resizedBitmap;
    }

• 对于没有根的设备，我只是使用MediaPlayer的内置method：

  bitmap bm = mmediaplayer.getCurrentFrame((;