SeekBar的使用和竖向的SeekBar

这是实现的几个seekbar的效果图，大家可以先看看：

第一个seekbar是以提供的bitmap为背景，然后进度条是透明的效果

<SeekBar        android:id="@+id/horiSeekBar"        android:layout_width="match_parent"        android:layout_height="wrap_content"         android:progressDrawable="@drawable/seekbar_progress_example"/>

对应的图片drawable xml

<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >     <item android:id="@android:id/background">        <bitmap android:src="@drawable/seekbarbackground"/>    </item>    <item android:id="@android:id/progress">        <clip>            <shape>            <solid android:color="@color/transparent" />        </shape>        </clip>    </item></layer-list>

第二个seekbar是以自己的shape为背景的，有进度条效果，同时添加一个thumb拖动条

<SeekBar        android:id="@+id/horiSeekBar02"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:layout_below="@id/horiText"         android:thumb="@drawable/switch_thumb"        android:progressDrawable="@drawable/progress_two"/>

对应progress的图片xml

<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >   <item android:id="@android:id/background">            <shape>            <solid android:color="@color/grey_eee" />            <corners android:radius="5dp" />        </shape>    </item>   <item android:id="@android:id/secondaryProgress">       <clip>        <shape>            <solid android:color="@color/green" />            <corners android:radius="5dp" />        </shape>        </clip>    </item></layer-list>

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下面要说的是这个竖向的seekbar，大致的思想就和网上很多写的一样，自定义一个verticalseekbar控件继承seekbar，在绘画的时候把canvas画布旋转90度，同时在onTouchEvent方法里，把拖动时需要的参数，由X变成Y。
我们在设置该控件的背景图片的时候发现，根本不起作用，或者说图片没有达到我们旋转的效果。因此我在onMeasure和onDraw方法里，去主动测量和绘制背景图片，达到我们预想的效果。

protected synchronized void onMeasure(int widthMeasureSpec,            int heightMeasureSpec) {        Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.seekbarbackground);        int heightMeasure = MeasureSpec.makeMeasureSpec(bitmap.getHeight(), MeasureSpec.EXACTLY);        int widthtMeasure = MeasureSpec.makeMeasureSpec(bitmap.getWidth(), MeasureSpec.EXACTLY);        super.onMeasure(heightMeasure, widthtMeasure);        setMeasuredDimension(heightMeasure, widthtMeasure);    }    @Override    protected synchronized void onDraw(Canvas canvas) {        canvas.rotate(-90);        canvas.translate(-getHeight(), 0);        super.onDraw(canvas);        Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.seekbarbackground);        Paint paint = new Paint();        canvas.drawBitmap(bitmap, 0,0, paint);    }    @Override    public boolean onTouchEvent(MotionEvent event) {        if (!isEnabled()) {            return false;        }        switch (event.getAction()) {        case MotionEvent.ACTION_DOWN:            if (isInScrollingContainer()) {                mTouchDownY = event.getY();            } else {                setPressed(true);                invalidate();                onStartTrackingTouch();                trackTouchEvent(event);                attemptClaimDrag();                onSizeChanged(getWidth(), getHeight(), 0, 0);            }            break;        case MotionEvent.ACTION_MOVE:            if (mIsDragging) {                trackTouchEvent(event);            } else {                final float y = event.getY();                if (Math.abs(y - mTouchDownY) > mScaledTouchSlop) {                    setPressed(true);                    invalidate();                    onStartTrackingTouch();                    trackTouchEvent(event);                    attemptClaimDrag();                }            }            onSizeChanged(getWidth(), getHeight(), 0, 0);            break;        case MotionEvent.ACTION_UP:            if (mIsDragging) {                trackTouchEvent(event);                onStopTrackingTouch();                setPressed(false);            } else {                // Touch up when we never crossed the touch slop threshold                // should                // be interpreted as a tap-seek to that location.                onStartTrackingTouch();                trackTouchEvent(event);                onStopTrackingTouch();            }            onSizeChanged(getWidth(), getHeight(), 0, 0);            // ProgressBar doesn't know to repaint the thumb drawable            // in its inactive state when the touch stops (because the            // value has not apparently changed)            invalidate();            break;        }        return true;    }    private void trackTouchEvent(MotionEvent event) {        final int height = getHeight();        final int top = getPaddingTop();        final int bottom = getPaddingBottom();        final int available = height - top - bottom;        int y = (int) event.getY();        float scale;        float progress = 0;        // 下面是最小值        if (y > height - bottom) {            scale = 0.0f;        } else if (y < top) {            scale = 1.0f;        } else {            scale = (float) (available - y + top) / (float) available;            progress = mTouchProgressOffset;        }        final int max = getMax();        progress += scale * max;        setProgress((int) progress);    }

demo下载链接：http://download.csdn.net/detail/yus201120/9872161