自动换行的线性布局

由于线性布局在横向时,控件较多超出屏幕也不会自行换行所以只好自己来实现了。
代码如下：

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.util.Log;
import android.view.Gravity;
import android.widget.LinearLayout;
import android.widget.TextView;
import com.ordering.util.Tools;

/**自动换行的线性布局
 * Created by huangqx on 2015-11-17 13:25.
 */
public class MyLinearLayout extends LinearLayout {
    private int width;//组件宽
    private int height;//组件高
    private int childCount;
    private int childMarginLeft = Tools.dip2px(getContext(),8);//子控件相对左边控件的距离
    private int childMarginHorizonTal = Tools.dip2px(getContext(),10);//子控件相对最左、最右的距离
    private int childMarginTop = Tools.dip2px(getContext(),8);//子控件相对顶部控件的距离
    private int childWidth=104;//子控件宽
    private int childHeight;//子控件高
    private int number=5;
    private int padding=6;

    public MyLinearLayout(Context context) {
        super(context);
    }

    public MyLinearLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
    }
//计算控件及其子控件所占区域
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        //super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        childCount = getChildCount();//得到子控件数量
        width = getDefaultSize(getSuggestedMinimumWidth(), widthMeasureSpec);
        if(childCount>0) {
        Paint pFont = new Paint();
            for (int i = 0; i < childCount; i++) {
                TextView childView =(TextView)getChildAt(i);//得到当前子控件
                String text=String.valueOf(childView.getText());                
                float strwid = pFont.measureText(text);
                if(strwid>childWidth){
                    childWidth=(int)strwid+padding;
                    number= width/(childWidth+childMarginLeft);
                    System.out.println("个数:"+number);
                    childWidth = (width - childMarginLeft * number) / number;
                }
            }
            childHeight = Tools.dip2px(getContext(), 39);//给子控件的高度一个定值
            //根据子控件的高和子控件数目得到自身的高
            height = childHeight * ((childCount-1)/ number+1) + childMarginHorizonTal * 2 + childMarginTop*((childCount-1)/number);
            Log.d("childHeight",childHeight+"");
        }else {
            //如果木有子控件，自身高度为0，即不显示
            height = 0;
        }
        Log.d("height",height+"");
        Log.d("childWidth",childWidth+"");
        //根据自身的宽度约束子控件宽度
        measureChildren(widthMeasureSpec, heightMeasureSpec);
        //设置自身宽度
        setMeasuredDimension(width, height);
    }
//控制子控件的换行
    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        /**
         * 遍历所有子控件，并设置它们的位置和大小
         * 每行只能有number个子控件，且高度固定，宽度相同，且每行正好布满
         */
        for (int i = 0; i < childCount; i++) {
            TextView childView =(TextView)getChildAt(i);//得到当前子控件
            childView.setGravity(Gravity.CENTER_VERTICAL|Gravity.CENTER_HORIZONTAL);
            childView.layout((i%number) * childWidth + (i%number+1)*childMarginLeft
                    , (i / number)*childHeight + childMarginHorizonTal + (i / number)*childMarginTop
                    , (i%number+1) * childWidth + (i%number+1)*childMarginLeft
                    , (i / number+1)*childHeight + childMarginHorizonTal + (i / number)*childMarginTop);
        }
    }
    //dispatchDraw：为布局控件添加边框
    @Override
    protected void onDraw(Canvas canvas) {
     Paint pFont = new Paint();
        for (int i = 0; i < childCount; i++) {
            TextView childView = (TextView) getChildAt(i);//得到当前子控件
            String text = String.valueOf(childView.getText());           
            canvas.drawText(text,childWidth/2,0,pFont);
        }
        super.onDraw(canvas);
    }
}