VerticalSeekBar和事件

Question

這裏是我的VerticalSeeker類：​​

public class VerticalSeekBar extends SeekBar implements SeekBar.OnSeekBarChangeListener{ 

    public VerticalSeekBar(Context context) { 
     super(context); 
     this.setOnSeekBarChangeListener(this); 
    } 

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

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

    public void onSizeChanged(int w, int h, int oldw, int oldh) { 
     super.onSizeChanged(h, w, oldh, oldw); 
    } 

    @Override 
    protected synchronized void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { 
     super.onMeasure(heightMeasureSpec, widthMeasureSpec); 
     setMeasuredDimension(getMeasuredHeight(), getMeasuredWidth()); 
    } 

    protected void onDraw(Canvas c) { 
     c.rotate(-90); 
     c.translate(-getHeight(), 0); 

     super.onDraw(c); 
    } 
@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((int) (getMax() * event.getY()/getHeight()) - 0); 
      onSizeChanged(getWidth(), getHeight(), 0, 0); 
      break; 

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

@Override 
public void onProgressChanged(SeekBar seekBar, int i, boolean b) { 
} 

@Override 
public void onStartTrackingTouch(SeekBar seekBar) 
{ 
    Toast.makeText(this.getContext(), "Start", Toast.LENGTH_SHORT).show(); 
} 

@Override 
public void onStopTrackingTouch(SeekBar seekBar) { 
    Toast.makeText(this.getContext(), "Stop", Toast.LENGTH_SHORT).show(); 
} 

}

有人能解釋，爲什麼只有 「onProgressChanged」 -event被解僱？如何獲得「onStartTrackingTouch」和「onStopTrackingTouch」的工作？

Answer 1

在最小的運動事件開關的情況下更改代碼以

case MotionEvent.ACTION_UP: 
    setProgress(getMax()- (int) (getMax() * event.getY()/getHeight())); 
    onSizeChanged(getWidth(), getHeight(), 0, 0); 
    onChangeListener.onStopTrackingTouch(this); 

找到完整實現在http://hackskrieg.wordpress.com/2012/04/20/working-vertical-seekbar-for-android/

Answer 2

公共類VerticalSeekBar擴展搜索欄{

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); 
} 

protected void onSizeChanged(int w, int h, int oldw, int oldh) { 
    super.onSizeChanged(h, w, oldh, oldw); 
} 

@Override 
protected synchronized void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { 
    super.onMeasure(heightMeasureSpec, widthMeasureSpec); 
    setMeasuredDimension(getMeasuredHeight(), getMeasuredWidth()); 
} 

protected void onDraw(Canvas c) { 
    c.rotate(-90); 
    c.translate(-getHeight(), 0); 

    super.onDraw(c); 
} 

private OnSeekBarChangeListener onChangeListener; 
@Override 
public void setOnSeekBarChangeListener(OnSeekBarChangeListener onChangeListener){ 
    this.onChangeListener = onChangeListener; 
} 

private int lastProgress = 0; 
@Override 
public boolean onTouchEvent(MotionEvent event) { 
    if (!isEnabled()) { 
     return false; 
    } 

    switch (event.getAction()) { 
    case MotionEvent.ACTION_DOWN: 
     onChangeListener.onStartTrackingTouch(this); 
     setPressed(true); 
     setSelected(true); 
     break; 
    case MotionEvent.ACTION_MOVE: 
     super.onTouchEvent(event); 
     int progress = getMax() - (int) (getMax() * event.getY()/getHeight()); 

     // Ensure progress stays within boundaries 
     if(progress < 0) {progress = 0;} 
     if(progress > getMax()) {progress = getMax();} 
     setProgress(progress); // Draw progress 
     if(progress != lastProgress) { 
      // Only enact listener if the progress has actually changed 
      lastProgress = progress; 
      onChangeListener.onProgressChanged(this, progress, true); 
     } 

     onSizeChanged(getWidth(), getHeight() , 0, 0); 
     setPressed(true); 
     setSelected(true); 
     break; 
    case MotionEvent.ACTION_UP: 
     onChangeListener.onStopTrackingTouch(this); 
     setPressed(false); 
     setSelected(false); 
     break; 
    case MotionEvent.ACTION_CANCEL: 
     super.onTouchEvent(event); 
     setPressed(false); 
     setSelected(false); 
     break; 
    } 
    return true; 
} 

public synchronized void setProgressAndThumb(int progress) { 
    setProgress(progress); 
    onSizeChanged(getWidth(), getHeight() , 0, 0); 
    if(progress != lastProgress) { 
     // Only enact listener if the progress has actually changed 
     lastProgress = progress; 
     onChangeListener.onProgressChanged(this, progress, true); 
    } 
} 

public synchronized void setMaximum(int maximum) { 
    setMax(maximum); 
} 

public synchronized int getMaximum() { 
    return getMax(); 
} 

}