问题描述

触摸移动时移动一个视图 (ACTION_MOVE)

我想做一个简单的控件：容器中有一个视图。如果我触摸容器移动手指，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)?我不需要使用一个界面，只要一个简单的布局。如何做到这一点呢?

解决方案

在main.xml用""@+id/root""来设置RelativeLayout

public class MyActivity extends Activity implements View.OnTouchListener {TextView _view;ViewGroup _root;private int _xDelta;private int _yDelta;@Overridepublic 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;}}