是否可以在适配器中设置OnTouchListener并从设置适配器的活动中调用它？

Question

我想在一个由arrayadapter创建并发送到listview的relativelayout上设置一个OnTouchListener。 但是必须将OnTouchListener触发的代码写入设置适配器的活动中。 是否可以将侦听器设置为适配器中的视图，并在活动中定义（或编码）它？

我的适配器：

public class MessageAdapter extends ArrayAdapter<FriendlyMessage> {

TouchInterface touchInterface;
protected AlphaAnimation fadeOut = new AlphaAnimation( 1.0f , 0.0f );
protected AlphaAnimation fadeIn = new AlphaAnimation( 0.0f , 1.0f );
ViewHolder viewHolder = new ViewHolder();

private static class ViewHolder {
    TextView messageText;
    TextView nameText;
    TextView timeText;
    ImageView imageView;
    RelativeLayout relativeLayout;
    int position;
}

public MessageAdapter(Context context, int resource, List<FriendlyMessage> objects) {
    super(context, resource, objects);
}

public void setOnTouchListener(View.OnTouchListener touchListener){
    this.touchInterface = (TouchInterface) touchListener;
    viewHolder.relativeLayout.setOnTouchListener(touchListener);
}

@Override
public View getView(final int position, View convertView, final ViewGroup parent) {

    FriendlyMessage message = getItem(position);

    if (message.getPhotoUrl() != null){
        if (Objects.equals(message.getKey(), String.valueOf(Build.SERIAL))){
            convertView = ((Activity) getContext()).getLayoutInflater().inflate(R.layout.item_message_image_right, null);
            viewHolder.relativeLayout = (RelativeLayout) convertView.findViewById(R.id.rel);
            viewHolder.imageView = (ImageView) convertView.findViewById(R.id.photoImageViewR);
            viewHolder.nameText = (TextView) convertView.findViewById(R.id.nameTextView);
            viewHolder.timeText = (TextView) convertView.findViewById(R.id.tvtimeimg);
            Picasso.with(viewHolder.imageView.getContext())
                    .load(message.getPhotoUrl())
                    .into(viewHolder.imageView);
            convertView.setTag(viewHolder);
        }
        else if (!Objects.equals(message.getKey(), String.valueOf(Build.SERIAL))){
            convertView = ((Activity) getContext()).getLayoutInflater().inflate(R.layout.item_message_image_left, null);
            viewHolder.relativeLayout = (RelativeLayout) convertView.findViewById(R.id.rel);
            viewHolder.imageView = (ImageView) convertView.findViewById(R.id.photoImageViewL);
            viewHolder.nameText = (TextView) convertView.findViewById(R.id.nameTextView);
            viewHolder.timeText = (TextView) convertView.findViewById(R.id.tvtimeimg);
            Picasso.with(viewHolder.imageView.getContext())
                    .load(message.getPhotoUrl())
                    .into(viewHolder.imageView);
            convertView.setTag(viewHolder);
        }
    }
    else if (message.getPhotoUrl() == null){
        if (Objects.equals(message.getKey(), String.valueOf(Build.SERIAL))) {
            convertView = ((Activity) getContext()).getLayoutInflater().inflate(R.layout.item_message_text_right, null);
            viewHolder.relativeLayout = (RelativeLayout) convertView.findViewById(R.id.rel);
            viewHolder.messageText = (TextView) convertView.findViewById(R.id.messageTextView);
            viewHolder.nameText = (TextView) convertView.findViewById(R.id.nameTextView);
            viewHolder.timeText = (TextView) convertView.findViewById(R.id.tvtime);
            viewHolder.messageText.setText(message.getText());
            convertView.setTag(viewHolder);

        } else if (!Objects.equals(message.getKey(), String.valueOf(Build.SERIAL))) {
            convertView = ((Activity) getContext()).getLayoutInflater().inflate(R.layout.item_message_text_left, null);
            viewHolder.relativeLayout = (RelativeLayout) convertView.findViewById(R.id.rel);
            viewHolder.messageText = (TextView) convertView.findViewById(R.id.messageTextView);
            viewHolder.nameText = (TextView) convertView.findViewById(R.id.nameTextView);
            viewHolder.timeText = (TextView) convertView.findViewById(R.id.tvtime);
            viewHolder.messageText.setText(message.getText());
            convertView.setTag(viewHolder);
        }
    }
//some other code here
    return convertView;
}}

触摸界面：

public interface TouchInterface {
void touch(View.OnTouchListener onTouchListener);}

我的活动是要调用侦听器（它的代码很长，所以我删除了一些现在不重要的部分）：

public class MessageActivity extends AppCompatActivity implements TouchInterface{

private static final String TAG = "MessageActivity";

public static final String ANONYMOUS = "anonymous";
public static final int DEFAULT_MSG_LENGTH_LIMIT = 1000;
public static final int RC_SIGN_IN = 1;
private static final int RC_PHOTO_PICKER = 2;

private ListView mMessageListView;
private MessageAdapter mMessageAdapter;
private ProgressBar mProgressBar;
private ImageButton mPhotoPickerButton;
private EditText mMessageEditText;
private Button mSendButton;
private FirebaseDatabase mFirebaseDatabase;
private DatabaseReference mMessagesDatabaseReference;
private static DatabaseReference mMessagesDatabaseReference2;
private ChildEventListener mChildEventListener;
private FirebaseAuth mFirebaseAuth;
private FirebaseAuth.AuthStateListener mAuthStateListener;
private FirebaseStorage mFirebaseStorage;
private StorageReference mStorageReference;

private String mUsername;
private Toolbar toolbar;
private String key = Build.SERIAL;

private SimpleDateFormat sdf = new SimpleDateFormat("yyyy.MM.dd");
private SimpleDateFormat sdft = new SimpleDateFormat("HH:mm");
private String time = sdft.format(new Date());
private String date = sdf.format(new Date());

public View.OnTouchListener listener;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_message);

    toolbar = (Toolbar) findViewById(R.id.toolbar);
    assert toolbar != null;
    setSupportActionBar(toolbar);
    getSupportActionBar().setDisplayHomeAsUpEnabled(true);
    getSupportActionBar().setHomeButtonEnabled(true);


    mUsername = ANONYMOUS;

    mFirebaseDatabase = FirebaseDatabase.getInstance();
    mFirebaseAuth = FirebaseAuth.getInstance();
    mMessagesDatabaseReference = mFirebaseDatabase.getReference().child("messages");
    mMessagesDatabaseReference2 = mFirebaseDatabase.getReference().child("touches");
    mFirebaseStorage = FirebaseStorage.getInstance();
    mStorageReference = mFirebaseStorage.getReference().child("photos");

    // Initialize references to views
    mProgressBar = (ProgressBar) findViewById(R.id.progressBar);
    mMessageListView = (ListView) findViewById(R.id.messageListView);
    mPhotoPickerButton = (ImageButton) findViewById(R.id.photoPickerButton);
    mMessageEditText = (EditText) findViewById(R.id.messageEditText);
    mSendButton = (Button) findViewById(R.id.sendButton);

    // Initialize message ListView and its adapter
    List<FriendlyMessage> friendlyMessages = new ArrayList<>();

    mMessageAdapter = new MessageAdapter(this, 0, friendlyMessages);
    mMessageListView.setAdapter(mMessageAdapter);
    mMessageAdapter.setOnTouchListener(listener);
//some other code here
}
//some other code here
@Override
public void touch(View.OnTouchListener listener1) {
    this.listener = listener1;
    Log.i(TAG, "touched");
    listener = new View.OnTouchListener() {
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            int x = (int) event.getX();
            int y = (int) event.getY();

            switch (event.getAction()) {
                case MotionEvent.ACTION_DOWN:
                    Log.i("TAG", "touched down");
                    break;
                case MotionEvent.ACTION_MOVE:
                    Log.i("TAG", "moving: (" + x + ", " + y + ")");
                    break;
                case MotionEvent.ACTION_UP:
                    Log.i("TAG", "touched up");
                    break;
            }

            mMessagesDatabaseReference2.push().setValue(x, y);

            return false;
        }
    };
}}

Answer 1

如果我理解正确，您想在列表元素上设置一个单击侦听器以执行父活动的方法（我想您将在其中传递相应的参数）。 如果我正确理解它，则应该在父活动类型的Adapter类中定义一个变量。 就像是

private MessageActivity activity;

然后在您的Adapter构造函数中

activity = (MessageActivity) context;

然后，当您在视图上设置点击侦听器时，您应该执行以下操作

view.setOnClickListener(new View.OnClickListener() {
         public void onClick(View v) {
             // Perform action on click
             activity.YourOnTouchMethodImplementation();
         }
     });