我想做一个简单的控件:一个里面有视图的容器。如果我触摸容器并移动手指,我想让视图跟着我的手指移动。

我应该使用什么样的容器(布局)?如何做到这一点?

我不需要使用一个表面,但一个简单的布局。


当前回答

按照@Andrew方法,如果你想要移动视图的中心,你只需要减去视图的一半高度和一半宽度。

float dX, dY;

@Override
public boolean onTouchEvent(View view, MotionEvent event) {
    switch (event.getAction()) {
        case MotionEvent.ACTION_DOWN:
            dX = view.getX() - event.getRawX();
            dY = view.getY() - event.getRawY();
            break;
        case MotionEvent.ACTION_MOVE:
            view.animate()
                .x(event.getRawX() + dX - (view.getWidth() / 2f))
                .y(event.getRawY() + dY - (view.getHeight() / 2f))
                .setDuration(0)
                .start();
            break;
        default:
            return false;
    }
    return true;
}     

其他回答

就像这样:

public class MyActivity extends Activity implements View.OnTouchListener {

TextView _view;
ViewGroup _root;
private int _xDelta;
private int _yDelta;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    _root = (ViewGroup)findViewById(R.id.root);

    _view = new TextView(this);
    _view.setText("TextView!!!!!!!!");

    RelativeLayout.LayoutParams layoutParams = new RelativeLayout.LayoutParams(150, 50);
    layoutParams.leftMargin = 50;
    layoutParams.topMargin = 50;
    layoutParams.bottomMargin = -250;
    layoutParams.rightMargin = -250;
    _view.setLayoutParams(layoutParams);

    _view.setOnTouchListener(this);
    _root.addView(_view);
}

public boolean onTouch(View view, MotionEvent event) {
    final int X = (int) event.getRawX();
    final int Y = (int) event.getRawY();
    switch (event.getAction() & MotionEvent.ACTION_MASK) {
        case MotionEvent.ACTION_DOWN:
            RelativeLayout.LayoutParams lParams = (RelativeLayout.LayoutParams) view.getLayoutParams();
            _xDelta = X - lParams.leftMargin;
            _yDelta = Y - lParams.topMargin;
            break;
        case MotionEvent.ACTION_UP:
            break;
        case MotionEvent.ACTION_POINTER_DOWN:
            break;
        case MotionEvent.ACTION_POINTER_UP:
            break;
        case MotionEvent.ACTION_MOVE:
            RelativeLayout.LayoutParams layoutParams = (RelativeLayout.LayoutParams) view.getLayoutParams();
            layoutParams.leftMargin = X - _xDelta;
            layoutParams.topMargin = Y - _yDelta;
            layoutParams.rightMargin = -250;
            layoutParams.bottomMargin = -250;
            view.setLayoutParams(layoutParams);
            break;
    }
    _root.invalidate();
    return true;
}}

在main.xml中只需要RelativeLayout + @+id/root即可

我发现了一个简单的方法来做到这一点与ViewPropertyAnimator:

float dX, dY;

@Override
public boolean onTouch(View view, MotionEvent event) {

    switch (event.getAction()) {

        case MotionEvent.ACTION_DOWN:

            dX = view.getX() - event.getRawX();
            dY = view.getY() - event.getRawY();
            break;

        case MotionEvent.ACTION_MOVE:

            view.animate()
                    .x(event.getRawX() + dX)
                    .y(event.getRawY() + dY)
                    .setDuration(0)
                    .start();
            break;
        default:
            return false;
    }
    return true;
}

//如果你想移动你的相机或任何东西,然后按照下面的方法来做 //我在相机上实现的情况下,你可以应用它在任何你想要的

public class VideoCallActivity extends AppCompatActivity implements 
  View.OnTouchListener {
 FrameLayout myLayout1;

@SuppressLint("ClickableViewAccessibility")
@Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
  //in the frame layout I am setting my camera
   myLayout1.setOnTouchListener(this);
  
  }

   float dX, dY;

@Override
public boolean onTouch(View view, MotionEvent event) {
    switch (event.getAction()) {
 //this is your code
        case MotionEvent.ACTION_DOWN:
            dX = view.getX() - event.getRawX();
            dY = view.getY() - event.getRawY();
            break;
        case MotionEvent.ACTION_MOVE:
            view.animate()
                    .x(event.getRawX() + dX)
                    .y(event.getRawY() + dY)
                    .setDuration(0)
                    .start();
            break;
        default:
            return false;
    }
    return true;
}

我推荐使用view。translationX和view。翻译来移动你的观点。

Kotlin snippet:

yourView.translationX = xTouchCoordinate
yourView.translationY = yTouchCoordinate

和@Alex Karshin的答案一样,我做了一点改变。

public class MovingObject implements OnTouchListener {
private RelativeLayout.LayoutParams lParams;
private PointF viewPoint, prePoint, currPoint;

public MovingObject() {
    lParams = null;
    viewPoint = new PointF();
    prePoint = new PointF();
    currPoint = new PointF();
}

public boolean onTouch(View view, MotionEvent event) {
    switch (event.getAction() & MotionEvent.ACTION_MASK) {
    case MotionEvent.ACTION_DOWN:
        viewPoint.set(view.getX(), view.getY());
        prePoint.set(event.getRawX(), event.getRawY());
        lParams = (RelativeLayout.LayoutParams) view.getLayoutParams();
        break;
    case MotionEvent.ACTION_UP:
        break;
    case MotionEvent.ACTION_POINTER_DOWN:
        break;
    case MotionEvent.ACTION_POINTER_UP:
        break;
    case MotionEvent.ACTION_MOVE:
        currPoint.set(event.getRawX(), event.getRawY());
        moveToCurrentPoint(view);
        break;
    }
    view.invalidate();
    return true;
}

private void moveToCurrentPoint(View view) {
    float dx = currPoint.x - prePoint.x - prePoint.x + viewPoint.x;
    float dy = currPoint.y - prePoint.y - prePoint.y + viewPoint.y;
    lParams.leftMargin = (int) (prePoint.x + dx);
    lParams.topMargin = (int) (prePoint.y + dy);
    view.setLayoutParams(lParams);
}
}