android 自定义View(三) 自定义ViewGroup之可添加的view

来源：互联网发布：c语言在线编程软件编辑：程序博客网时间：2024/05/22 05:13

在这章我，我们将通过自定义的一个ViewGroup来实现一个类似于今日头条中编辑分类添加的效果。
首先，需要先继承一个ViewGroup。

public class MyViewGroup extends ViewGroup{    public MyViewGroup(Context context,AttributeSet attrs) {        super(context);        // TODO Auto-generated constructor stub        addView(CreatView());    } }

因为在这个group中可以添加新的子view，所有需要对view的大小左处理

    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {        super.onMeasure(widthMeasureSpec, heightMeasureSpec);//        int sizeWidth = MeasureSpec.getSize(widthMeasureSpec);//        int sizeHeight = MeasureSpec.getSize(heightMeasureSpec);//        int modeWidth = MeasureSpec.getMode(widthMeasureSpec);//        int modeHeight = MeasureSpec.getMode(heightMeasureSpec);        int childCount = getChildCount();        Log.d("HK", "childCount = "+childCount);        if(childCount == 0) {            setMeasuredDimension(0, 0);            Log.d("HK", "setMeasuredDimension(0, 0)");        } else {            Log.d("HK", "setMeasuredDimension(chirldWidth, chirldHight)");            for(int i=0;i<childCount;i++) {                TextView tvChild = (TextView) getChildAt(i);                measureChild(tvChild, widthMeasureSpec, heightMeasureSpec);                  int childWidth = tvChild.getMeasuredWidth();                int childHight = tvChild.getMeasuredHeight();                int row = i-1/4;                Log.d("HK", "childWitch = "+childWidth);                setMeasuredDimension(childWidth*4, (childHight)*(row+1));                Log.d("HK", "setMeasuredDimension w h = "+childWidth*4+" "+childHight*(row+1));            }        }    }

这面通过多次Measure子view的高和宽来设置viewGroup的高宽，此处保证每行4个，超过4个则添加一行。在设置好viewGroup后，接下来就需要将子View安放在里面。

    protected void onLayout(boolean changed, int l, int t, int r, int b) {        // TODO Auto-generated method stub        int childCount = getChildCount();        int left = 0;        //int row = childCount/4;        int mod = childCount%4;        int row = 0;        TextView childView;        for(int i=0;i<childCount;i++) {            childView = (TextView) getChildAt(i);            if(i==childCount-1) {            //给最后一个子view添加点击事件，通过点击可以新建一个子view                childView.setText("点击添加");                childView.setBackgroundColor(Color.BLUE);                childView.setTextColor(Color.BLACK);                childView.setOnClickListener(new OnClickListener() {                    @Override                    public void onClick(View v) {                        // TODO Auto-generated method stub                        Log.d("HK", "onLayout Click");                        addView(CreatView());                        //requestLayout();                        invalidate();                    }                });            } else {                childView.setText("新加入的");                childView.setTextColor(Color.BLACK);                childView.setBackgroundColor(Color.GREEN);            }            int width = childView.getMeasuredWidth();            Log.d("HK", "onLayout = "+width+" "+childView.getHeight());            row = i/4;            if((i+1)%4==1&&row!=0) {                left = 0;                Log.d("HK", "onLayout change line");            }            childView.layout(left, childView.getMeasuredHeight()*row, left+width, childView.getMeasuredHeight()*(row+1));            Log.d("HK", "childView.layout left top right buttom= "+left+" "+0+" "+(left+width)+" "+childView.getMeasuredHeight());            left += width;            Log.d("HK", "onLayout row =  "+row +" "+i%4+" "+i);        }    }    //新建子view的方法    protected TextView CreatView() {        TextView tv = new TextView(MyContext.getContext());        tv.setHeight(80);        tv.setWidth(220);        return tv;    }

详细代码请见github
GITHUB:https://github.com/everyhappy/myViews

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