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

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())

其他回答

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())

在Kotlin中实现相同

    rightPanel.setOnTouchListener(View.OnTouchListener { view, event ->
        when (event?.action) {
            MotionEvent.ACTION_DOWN -> {

                rightDX = view!!.x - event.rawX
                // rightDY = view!!.getY() - event.rawY;

            }
            MotionEvent.ACTION_MOVE -> {

                var displacement = event.rawX + rightDX

                view!!.animate()
                        .x(displacement)
                        // .y(event.getRawY() + rightDY)
                        .setDuration(0)
                        .start()
            }
            else -> { // Note the block
                return@OnTouchListener false
            }
        }
        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);
}
}

触摸容器,视图将跟随您的手指。

xml代码

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    android:id="@+id/floating_layout"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    >

    <ImageView
      android:id="@+id/btn_chat"
      android:layout_width="42dp"
      android:layout_height="42dp"
      />
    
<LinearLayout>

Java代码

public class DashBoardActivity extends Activity implements View.OnClickListener, View.OnTouchListener {
    
    float dX;
    float dY;
    int lastAction;
    LinearLayout floatingLayout;

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

        floatingLayout = findViewById(R.id.floating_layout);
        floatingLayout.setOnTouchListener(this);    
    
    
    
     @Override
    public boolean onTouch(View view, MotionEvent event) {
        switch (event.getActionMasked()) {
            case MotionEvent.ACTION_DOWN:
                dX = view.getX() - event.getRawX();
                dY = view.getY() - event.getRawY();
                lastAction = MotionEvent.ACTION_DOWN;
                break;

            case MotionEvent.ACTION_MOVE:
                view.setY(event.getRawY() + dY);
                view.setX(event.getRawX() + dX);
                lastAction = MotionEvent.ACTION_MOVE;
                break;

            case MotionEvent.ACTION_UP:
                if (lastAction == MotionEvent.ACTION_DOWN)
                    Toast.makeText(DashBoardActivity.this, "Clicked!", Toast.LENGTH_SHORT).show();
                break;

            default:
                return false;
        }
        return true;
    }
}