关于android 怎样安装 assets文件下的apk

在自己的app中安装assets文件夹下的apk文件

public class MainActivity extends Activity {
	Context mContext;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		mContext = this;
		//Toast.makeText(this, ""+Environment.getExternalStorageDirectory().getAbsolutePath(), 0).show();
		if(copyApkFromAssets(this, "test.apk", Environment.getExternalStorageDirectory().getAbsolutePath()+"/test.apk")){
			Builder m = new AlertDialog.Builder(mContext)
				.setIcon(R.drawable.ic_launcher).setMessage("是否安装？")
				.setIcon(R.drawable.ic_launcher)
				.setPositiveButton("yes", new OnClickListener() {
				@Override
				public void onClick(DialogInterface dialog, int which) {
				Intent intent = new Intent(Intent.ACTION_VIEW);
				intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
				intent.setDataAndType(Uri.parse("file://" + Environment.getExternalStorageDirectory().getAbsolutePath()+"/test.apk"),
											           "application/vnd.android.package-archive");
										mContext.startActivity(intent);
										}
									});
			m.show();
		}

	}
	 public boolean copyApkFromAssets(Context context, String fileName, String path) {
		 boolean copyIsFinish = false;
		 try {
			 InputStream is = context.getAssets().open(fileName);
			 File file = new File(path);
			 file.createNewFile();
			 FileOutputStream fos = new FileOutputStream(file);
			 byte[] temp = new byte[1024];
			 int i = 0;
			 while ((i = is.read(temp)) > 0) {
				 fos.write(temp, 0, i);
			 }
			 fos.close();
			 is.close();
			 copyIsFinish = true;
		 } catch (IOException e) {
			 e.printStackTrace();
		 }
		 return copyIsFinish;
	 }
}