Android下載app完成後自動安裝

直接上代碼了
public class MainActivity extends Activity {

	private DownloadManager dowanloadmanager = null;
	private DownloadChangeObserver downloadObserver;
	private long lastDownloadId = 0;
	public static final Uri CONTENT_URI = Uri.parse("content://downloads/my_downloads");


	@Override
	protected void onCreate(Bundle savedInstanceState) {
	// TODO Auto-generated method stub
	super.onCreate(savedInstanceState);
	setContentView(R.layout.activity_main);
	String serviceString = Context.DOWNLOAD_SERVICE;
	dowanloadmanager = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);

	Uri uri = Uri.parse("http://filelx.liqucn.com/upload/2014/sheji/ms_hdl_daiji_lq_20140811.apk");
	Environment.getExternalStoragePublicDirectory(
	Environment.DIRECTORY_DOWNLOADS).mkdir();


	lastDownloadId = dowanloadmanager.enqueue(new 	DownloadManager.Request(uri).setAllowedNetworkTypes(DownloadManager.Request.NETWORK_MOBILE
	| DownloadManager.Request.NETWORK_WIFI).setAllowedOverRoaming(false).setDestinationInExternalPublicDir(
	Environment.DIRECTORY_DOWNLOADS, "test.apk"));
	registerReceiver(receiver, new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE));
	downloadObserver = new DownloadChangeObserver(null);
	getContentResolver().registerContentObserver(CONTENT_URI, true,downloadObserver);
}


class DownloadChangeObserver extends ContentObserver {

	public DownloadChangeObserver(Handler handler) {
	super(handler);
	// TODO Auto-generated constructor stub
	}


	@Override
	public void onChange(boolean selfChange) {
	queryDownloadStatus();
	}


}


private BroadcastReceiver receiver = new BroadcastReceiver() {
	@Override
	public void onReceive(Context context, Intent intent) {
	// 這裏可以取得下載的id，這樣就可以知道哪個文件下載完成了。適用與多個下載任務的監聽
	long myDwonloadID = intent.getLongExtra(
	DownloadManager.EXTRA_DOWNLOAD_ID, -1);
	if (lastDownloadId == myDwonloadID) {
	try {
	String serviceString = Context.DOWNLOAD_SERVICE;
	DownloadManager dManager = (DownloadManager) context
	.getSystemService(serviceString);
	Intent install = new Intent(Intent.ACTION_VIEW);
	Uri downloadFileUri = dManager.getUriForDownloadedFile(myDwonloadID);
	install.setDataAndType(downloadFileUri,"application/vnd.android.package-archive");
	install.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
	context.startActivity(install);
	} catch (Exception e) {
	// TODO: handle exception
	e.printStackTrace();
	Log.e("異常", "install error ", e);
	}
}
	queryDownloadStatus();
	}
};


private void queryDownloadStatus() {
	DownloadManager.Query query = new DownloadManager.Query();
	query.setFilterById(lastDownloadId);
	Cursor c = dowanloadmanager.query(query);
	if (c != null && c.moveToFirst()) {
	int status = c.getInt(c.getColumnIndex(DownloadManager.COLUMN_STATUS));


	int reasonIdx = c.getColumnIndex(DownloadManager.COLUMN_REASON);
	int titleIdx = c.getColumnIndex(DownloadManager.COLUMN_TITLE);
	int fileSizeIdx = c.getColumnIndex(DownloadManager.COLUMN_TOTAL_SIZE_BYTES);
	int bytesDLIdx = c.getColumnIndex(DownloadManager.COLUMN_BYTES_DOWNLOADED_SO_FAR);
	String title = c.getString(titleIdx);
	int fileSize = c.getInt(fileSizeIdx);
	int bytesDL = c.getInt(bytesDLIdx);


	// Translate the pause reason to friendly text.
	int reason = c.getInt(reasonIdx);
	StringBuilder sb = new StringBuilder();
	sb.append(title).append("\n");
	sb.append("Downloaded ").append(bytesDL).append(" / ")
	.append(fileSize);


	// Display the status
	Log.d("tag", sb.toString());
	switch (status) {
	case DownloadManager.STATUS_PAUSED:
	Log.v("tag", "STATUS_PAUSED");
	case DownloadManager.STATUS_PENDING:
	Log.v("tag", "STATUS_PENDING");
	case DownloadManager.STATUS_RUNNING:
	// 正在下載，不做任何事情
	Log.v("tag", "STATUS_RUNNING");


	break;
	case DownloadManager.STATUS_SUCCESSFUL:
	// 完成
	Log.v("tag", "下載完成");
	// dowanloadmanager.remove(lastDownloadId);
	break;
	case DownloadManager.STATUS_FAILED:
	// 清除已下載的內容，重新下載
	Log.v("tag", "STATUS_FAILED");
	dowanloadmanager.remove(lastDownloadId);
	break;
	}
}
}


	@Override
	protected void onDestroy() {
	// TODO Auto-generated method stub
	super.onDestroy();
	unregisterReceiver(receiver);
	getContentResolver().unregisterContentObserver(downloadObserver);
}