Android控件结构和自定义控件【5】

重写view实现全新的控件

两个关键的方法 

1. onMeasure() 方法

    @Override
    protected void onMeasure(int widthMeasureSpec,
                             int heightMeasureSpec) {
        mMeasureWidth = MeasureSpec.getSize(widthMeasureSpec);
        mMeasureHeigth = MeasureSpec.getSize(heightMeasureSpec);
        setMeasuredDimension(mMeasureWidth, mMeasureHeigth);
        //TODO
        //...
    }

2. onDraw()方法

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        for (int i = 0; i < mRectCount; i++) {
            mRandom = Math.random();
            float currentHeight = (float) (mRectHeight * mRandom);
            canvas.drawRect(
                    (float) (mWidth * 0.4 / 2 + mRectWidth * i + offset),
                    currentHeight,
                    (float) (mWidth * 0.4 / 2 + mRectWidth * (i + 1)),
                    mRectHeight,
                    mPaint);
        }
        //定时刷新
        postInvalidateDelayed(300);
    }

标签：控件,canvas,onDraw,自定义,int,float,0.4,Android
来源： https://blog.csdn.net/xfb1989/article/details/94441920