android竖着的seekbar

以前网上有位虾士发过一篇文章是关于竖着的seekbar,但是也没有确定是否可行.最近看了vlc的音效处理.就是用到竖着的seekbar,所以分享下代码:
也可以自己查看它的源码:

import android.content.Context;
import android.graphics.Canvas;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.widget.SeekBar;

public class VerticalSeekBar extends SeekBar {

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

    public VerticalSeekBar(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    public VerticalSeekBar(Context context, AttributeSet attrs) {
        super(context, attrs);
    }
//这是一个重点,高宽倒置
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(h, w, oldh, oldw);
    }
//这是一个重点,高宽倒置
    @Override
    protected synchronized void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(heightMeasureSpec, widthMeasureSpec);
        setMeasuredDimension(getMeasuredHeight(), getMeasuredWidth());
    }

//这是一个重点
    protected void onDraw(Canvas c) {
        c.rotate(-90);
        c.translate(-getHeight(), 0);

        super.onDraw(c);
    }
//这是一个重点,高宽倒置
    @Override
    public synchronized void setProgress(int progress) {
        super.setProgress(progress);
        onSizeChanged(getWidth(), getHeight(), 0, 0);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        if (!isEnabled()) {
            return false;
        }

        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
            case MotionEvent.ACTION_MOVE:
            case MotionEvent.ACTION_UP:
                setProgress(getMax() - (int) (getMax() * event.getY() / getHeight()));
                onSizeChanged(getWidth(), getHeight(), 0, 0);
                break;

            case MotionEvent.ACTION_CANCEL:
                break;
        }
        return true;
    }

没有重点了,直接使用吧.