package com.imooc.dragviewtest;
import android.content.Context;
import android.graphics.Color;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
public class DragView2 extends View {
private int lastX;
private int lastY;
public DragView2(Context context) {
super(context);
ininView();
}
public DragView2(Context context, AttributeSet attrs) {
super(context, attrs);
ininView();
}
public DragView2(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
ininView();
}
private void ininView() {
setBackgroundColor(Color.BLUE);
}
// 绝对坐标方式
@Override
public boolean onTouchEvent(MotionEvent event) {
int rawX = (int) (event.getRawX());
int rawY = (int) (event.getRawY());
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
// 记录触摸点坐标
lastX = rawX;
lastY = rawY;
break;
case MotionEvent.ACTION_MOVE:
// 计算偏移量
int offsetX = rawX - lastX;
int offsetY = rawY - lastY;
// 在当前left、top、right、bottom的基础上加上偏移量
layout(getLeft() + offsetX,
getTop() + offsetY,
getRight() + offsetX,
getBottom() + offsetY);
// 重新设置初始坐标
lastX = rawX;
lastY = rawY;
break;
}
return true;
}
}