public class MyVolumnView extends View {    int count_dark = 7;    final int MAX_COUNT = 15;    Paint paint;    Bitmap dark;    Bitmap light;    final int SPAN = 5;    public MyVolumnView(Context context, AttributeSet attrs) {        super(context, attrs);        paint = new Paint();        dark = BitmapFactory.decodeResource(getResources(),                R.drawable.sound_line1);        light = BitmapFactory.decodeResource(getResources(),                R.drawable.sound_line);    }    @Override    protected void onDraw(Canvas canvas) {        // TODO Auto-generated method stub        // 画的黑条目        for (int i = 0; i < count_dark; i++) {            canvas.drawBitmap(dark,                    new Rect(0, 0, dark.getWidth(), dark.getHeight()),                    new Rect(0, i * (dark.getHeight() + SPAN), dark.getWidth(),                            i * (dark.getHeight() + SPAN) + dark.getHeight()),                    paint);        }        // 画亮条目        for (int j = count_dark; j < MAX_COUNT; j++) {            canvas.drawBitmap(light,                    new Rect(0, 0, dark.getWidth(), dark.getHeight()),                    new Rect(0, j * (dark.getHeight() + SPAN), dark.getWidth(),                            j * (dark.getHeight() + SPAN) + dark.getHeight()),                    paint);        }        super.onDraw(canvas);    }    @Override    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {        //决定控件的宽高        int realWidth = getRealSize(widthMeasureSpec, true);        int realHeight = getRealSize(heightMeasureSpec, false);        this.setMeasuredDimension(realWidth, realHeight);    }    @Override    public boolean onTouchEvent(MotionEvent event) {        //触摸事件        int action = event.getAction();        float x = 0, y = 0;        switch (action) {        case MotionEvent.ACTION_DOWN:            x = event.getX();            y = event.getY();            break;        case MotionEvent.ACTION_MOVE:            x = event.getX();            y = event.getY();            break;        case MotionEvent.ACTION_UP:            x = event.getX();            y = event.getY();            break;        default:            break;        }        if (x > dark.getWidth()) {            return true;        }        float percent = y                / (MAX_COUNT * dark.getHeight() + (MAX_COUNT - 1) * SPAN);        if (percent > 1) {            return true;        }        count_dark = (int) (percent * 15);        this.invalidate();        // Log.i("INFO", "count of dark is:"+count_dark);        return true;    }    private int getRealSize(int length, boolean isWidth) {        int realSize = 0;        int specMode = MeasureSpec.getMode(length);        int size = MeasureSpec.getSize(length);        int padding = isWidth ? this.getPaddingLeft() + this.getPaddingRight()                : this.getPaddingTop() + this.getPaddingBottom();        if (specMode == MeasureSpec.EXACTLY) {            realSize = size;        } else {            realSize = isWidth ? dark.getWidth() + padding : MAX_COUNT                    * (dark.getHeight() + padding) + (MAX_COUNT - 1) * SPAN;            if (specMode == MeasureSpec.UNSPECIFIED) {                realSize = Math.min(realSize, size);            }        }        Log.i("INFO", "realSize:" + realSize);        return realSize;    }}