Recording Videos Simply 簡單錄製視頻

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.csdn.net/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);}