系统隐式 Intent

1. 找出系统中所有视频

private void choiceFile() {

    Intent intent = new Intent(Intent.ACTION_PICK,
            android.provider.MediaStore.Video.Media.EXTERNAL_CONTENT_URI);
    intent.setDataAndType(MediaStore.Video.Media.EXTERNAL_CONTENT_URI, "video/*");
    Intent wrapperIntent = Intent.createChooser(intent, null);
    startActivityForResult(wrapperIntent, VIDEO_REQUSET_CODE);
}