Android12 录屏时代码设置不显示屏幕上悬浮窗

在 Android 12 中，录屏时默认不会显示悬浮窗，这是为了保护用户的隐私和安全。如果您需要在录屏时显示悬浮窗，可以使用以下代码：

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
    MediaProjectionManager mediaProjectionManager = (MediaProjectionManager) getSystemService(MEDIA_PROJECTION_SERVICE);
    MediaProjection mediaProjection = mediaProjectionManager.getMediaProjection(Activity.RESULT_OK, mScreenCaptureIntent);
    DisplayMetrics metrics = getResources().getDisplayMetrics();
    int screenWidth = metrics.widthPixels;
    int screenHeight = metrics.heightPixels;
    int screenDensity = metrics.densityDpi;
    MediaRecorder mediaRecorder = new MediaRecorder();
    mediaRecorder.setVideoSource(MediaRecorder.VideoSource.SURFACE);
    mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
    mediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.H264);
    mediaRecorder.setVideoSize(screenWidth, screenHeight);
    mediaRecorder.setVideoFrameRate(30);
    mediaRecorder.setVideoEncodingBitRate(5 * 1024 * 1024);
    mediaRecorder.setVideoEncoder(MediaRecorder.AudioEncoder.AMR_NB);
    mediaRecorder.setAudioSamplingRate(44100);
    mediaRecorder.setAudioChannels(1);
    mediaRecorder.setAudioEncodingBitRate(16 * 1024);
    mediaRecorder.setOutputFile(getSaveDirectory() + "/" + fileName);
    Surface inputSurface = mediaRecorder.createInputSurface();
    Display display = getWindowManager().getDefaultDisplay();
    Surface displaySurface = display.createVirtualDisplay("Recording Display", screenWidth, screenHeight, screenDensity, null, DisplayManager.VIRTUAL_DISPLAY_FLAG_PRESENTATION, inputSurface, null);
    mediaRecorder.prepare();
    mediaRecorder.start();
    showFloatingWindow();
}

其中 `showFloatingWindow()` 方法是您自己实现的显示悬浮窗的方法。注意，在 Android 12 中，您需要在应用程序的 `AndroidManifest.xml` 文件中添加 `android.permission.CAPTURE_VIDEO_OUTPUT` 权限才能录制屏幕。