Android疑难杂症-控件任意拖动+点击监听

Android疑难杂症
  1. 1. 实现代码(ImageView为例)

实现代码(ImageView为例)

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package com.keqiang.highcloud.ui.widget;
  
import android.annotation.SuppressLint;
import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.ViewGroup;
import android.widget.ImageView;
  
  
/**
 * Created by KID on 2017/11/14.
 * 随意拖动的view
 */
@SuppressLint("AppCompatCustomView")
public class DragView extends ImageView {
  
    private int width;
    private int height;
    private int screenWidth;
    private int screenHeight;
    private Context context;
  
    private boolean dragEnable = true;
    //是否拖动
    private boolean isDrag = false;
  
    public boolean isDrag() {
        return isDrag;
    }
  
    public boolean isDragEnable() {
        return dragEnable;
    }
  
    public void setDragEnable(boolean dragEnable) {
        this.dragEnable = dragEnable;
    }
  
    public DragView(Context context, AttributeSet attrs) {
        super(context, attrs);
        dragEnable = true;
        this.context = context;
    }
  
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        width = getMeasuredWidth();
        height = getMeasuredHeight();
    }
  
    private float downX;
    private float downY;
  
    @Override
    public boolean onTouchEvent(MotionEvent event) {
        super.onTouchEvent(event);
        if (this.isEnabled()) {
            switch (event.getAction()) {
                case MotionEvent.ACTION_DOWN:
                    isDrag = false;
                    ViewGroup mViewGroup = (ViewGroup) getParent();
                    if (null != mViewGroup) {
                        screenWidth = mViewGroup.getWidth();
                        screenHeight = mViewGroup.getHeight();
                    }
                    downX = event.getX();
                    downY = event.getY();
                    break;
                case MotionEvent.ACTION_MOVE:
                    Log.e("kid", "ACTION_MOVE");
                    if (dragEnable) {
                        final float xDistance = event.getX() - downX;
                        final float yDistance = event.getY() - downY;
                        int l, r, t, b;
                        //当水平或者垂直滑动距离大于10,才算拖动事件
                        if (Math.abs(xDistance) > 10 || Math.abs(yDistance) > 10) {
                            Log.e("kid", "Drag");
                            isDrag = true;
                            l = (int) (getLeft() + xDistance);
                            r = l + width;
                            t = (int) (getTop() + yDistance);
                            b = t + height;
                            //不划出边界判断,此处应按照项目实际情况,因为本项目需求移动的位置是手机全屏,
                            // 所以才能这么写,如果是固定区域,要得到父控件的宽高位置后再做处理
                            if (l < 0) {
                                l = 0;
                                r = l + width;
                            } else if (r > screenWidth) {
                                r = screenWidth;
                                l = r - width;
                            }
                            if (t < 0) {
                                t = 0;
                                b = t + height;
                            } else if (b > screenHeight) {
                                b = screenHeight;
                                t = b - height;
                            }

                            this.layout(l, t, r, b);
                        }
                    }
                    break;
                case MotionEvent.ACTION_UP:
                    setPressed(false);
                    break;
                case MotionEvent.ACTION_CANCEL:
                    setPressed(false);
                    break;
            }
            return true;
        }
        return false;
    }
}
Android
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