Recording Videos Simply 简单录制视频

Your application has a job to do, and integrating videos is only a small part of it. You want to take videos with minimal fuss, and not reinvent the camcorder. Happily, most Android-powered devices already have a camera application that records video. In this lesson, you make it do this for you.http://blog.youkuaiyun.com/sergeycao

Request Camera Permission

To advertise that your application depends on having a camera, put a <uses-feature> tag in the manifest file:

<manifest ... >
    <uses-feature android:name="android.hardware.camera" />
    ...
</manifest ... >

If your application uses, but does not require a camera in order to function, add android:required="false" to the tag. In doing so, Google Play will allow devices without a camera to download your application. It's then your responsibility to check for the availability of the camera at runtime by calling hasSystemFeature(PackageManager.FEATURE_CAMERA). If a camera is not available, you should then disable your camera features.

Record a Video with a Camera App

The Android way of delegating actions to other applications is to invoke an Intent that describes what you want done. This involves three pieces: the Intent itself, a call to start the external Activity, and some code to handle the video when focus returns to your activity.

Here's a function that invokes an intent to capture video.

private void dispatchTakeVideoIntent() {
    Intent takeVideoIntent = new Intent(MediaStore.ACTION_VIDEO_CAPTURE);
    startActivityForResult(takeVideoIntent, ACTION_TAKE_VIDEO);
}

It's a good idea to make sure an app exists to handle your intent before invoking it. Here's a function that checks for apps that can handle your intent:

public static boolean isIntentAvailable(Context context, String action) {
    final PackageManager packageManager = context.getPackageManager();
    final Intent intent = new Intent(action);
    List<ResolveInfo> list =
        packageManager.queryIntentActivities(intent,
            PackageManager.MATCH_DEFAULT_ONLY);
    return list.size() > 0;
}

View the Video

The Android Camera application returns the video in the Intent delivered to onActivityResult() as a Uri pointing to the video location in storage. The following code retrieves this video and displays it in a VideoView.

private void handleCameraVideo(Intent intent) {
    mVideoUri = intent.getData();
    mVideoView.setVideoURI(mVideoUri);
}