android 自定义View

来源：互联网发布：数据库笛卡尔积是什么编辑：程序博客网时间：2024/06/06 21:44

自定义View分为三个步骤

onMeasure 测量宽高

onLayout 给空间定位

onDraw 绘制控件

自定义View 的几种实现

1.继承View

完成测量需要注意的细节

int mWidth;int mHeight;@Overrideprotected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {    super.onMeasure(widthMeasureSpec,heightMeasureSpec);    int widthMode = MeasureSpec.getMode(widthMeasureSpec);    int heightMode=MeasureSpec.getMode(heightMeasureSpec);    int widthSize = MeasureSpec.getSize(widthMeasureSpec);    int heightSize = MeasureSpec.getSize(heightMeasureSpec);    //是否是warp_content模式    if (widthMode==MeasureSpec.AT_MOST&&heightMode==MeasureSpec.AT_MOST){        setMeasuredDimension(mWidth,mHeight);    }else if(widthMode==MeasureSpec.AT_MOST){        setMeasuredDimension(mWidth,heightSize);    }else if (heightMode==MeasureSpec.AT_MOST){        setMeasuredDimension(widthSize,mHeight);    }}

0 0