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

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);
}
}

其他回答

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;
}     

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;
}

kotlin的简单代码:

var dx = 0f
var dy = 0f

private fun setMyViewListener(): OnTouchListener {
    return OnTouchListener { view, event ->

        when (event.action) {
            MotionEvent.ACTION_DOWN -> {
                dx = view.x - event.rawX
                dx = view.y - event.rawY
            }
            MotionEvent.ACTION_MOVE -> view.animate()
                    .x(event.rawX + dx)
                    //.y(event.rawY + dy) // uncomment this line to move y
                    .setDuration(0)
                    .start()
        }

        true
    }
}

然后像这样调用它:

var myView = findViewById<ConstraintLayout>(R.id.myView)
myView.setOnTouchListener(setMyViewListener())

//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