android 悬浮拖动控件,Android自定义可拖动的悬浮布局

首先上效果图

拖动

这个自定义的View是继承RelativeLayout的，所以在写xml布局的时候直接当成RelativeLayout使用即可。

由于在该类中注释的很清楚，在这里我就不再累赘直接上代码

public class MyDragView extends RelativeLayout {

private ViewDragHelper mDragger;

private View mAutoBackView;

public MyDragView(Context context, AttributeSet attrs) {

super(context, attrs);

mDragger = ViewDragHelper.create(this, 1.0f, new ViewDragHelper.Callback() {

@Override

public int getViewHorizontalDragRange(View child) {

//返回可拖动的子视图的水平运动范围(以像素为单位)的大小。

//对于不能垂直移动的视图，此方法应该返回0。

return getMeasuredWidth() - child.getMeasuredWidth();

}

@Override

public int getViewVerticalDragRange(View child) {

//返回可拖动的子视图的竖直运动范围(以像素为单位)的大小。

//对于不能垂直移动的视图，此方法应该返回0。

return getMeasuredHeight() - child.getMeasuredHeight();

}

@Override

public boolean tryCaptureView(View child, int pointerId) {

//返回true表view示捕获当前touch到的

return true;

}

@Override

public int clampViewPositionHorizontal(View child, int left, int dx) {

if (left > getWidth() - child.getMeasuredWidth()){

//超出左侧边界处理

left = getWidth() - child.getMeasuredWidth();

} else if (left < 0) {

//超出右侧边界处理

left = 0;

}

return left;

}

@Override

public int clampViewPositionVertical(View child, int top, int dy) {

if (top > getHeight() - child.getMeasuredHeight()){

//超出下边界处理

top = getHeight() - child.getMeasuredHeight();

} else if (top < 0) {

//超出上边界处理

top = 0;

}

return top;

}

});

mDragger.setEdgeTrackingEnabled(ViewDragHelper.EDGE_LEFT);

}

@Override

public boolean onInterceptTouchEvent(MotionEvent event) {

return mDragger.shouldInterceptTouchEvent(event);

}

@Override

public boolean onTouchEvent(MotionEvent event) {

//点击位置坐标

int downX = (int) event.getX();

int downY = (int) event.getY();

//悬浮区域左上角坐标

int x = (int) mAutoBackView.getX();

int y = (int) mAutoBackView.getY();

//悬浮区域宽高

int width = mAutoBackView.getWidth();

int height = mAutoBackView.getHeight();

if ((downX >= x && downY >= y) && (downX <= (x+width) && downY <= (y+height)) ) {

//点击在悬浮区域内部进行事件拦截，否则不拦截

try {

mDragger.processTouchEvent(event);

return true;

}catch (IllegalArgumentException e){

return false;

}

} else {

return false;

}

}

@Override

public void computeScroll() {

if (mDragger.continueSettling(true)) {

invalidate();

}

}

/**

* onFinishInflate 当View中所有的子控件均被映射成xml后触发

*/

@Override

protected void onFinishInflate() {

super.onFinishInflate();

mAutoBackView = getChildAt(0);

}

}