android 垂直 SeekBar 源代码(VerticalSeekBar)[转]

主要是继承 AbsSeekBar 然后修改下面这些方法

onProgressRefresh（） //当进度条数据更新的时候，例如我们拖动滑动条的时候，这个方法被调用

setThumbPos（） //这个方法是设置Thumb的位置

onDraw（） //这个是负责画界面

onSizeChanged（） //更新画布尺寸

onTouchEvent（） //当触摸屏幕的时候被调用

trackTouchEvent（） //当拖动滑动条的时候，这个被调用

还有就是添加一个接口这个接口是SeekBar 的一个内部接口 public interface OnSeekBarChangeListener

里面有三个方法:

public void onProgressChanged(VerticalSeekBar vBar, int progress,boolean fromUser);
public void onStartTrackingTouch(VerticalSeekBar vBar);
public void onStopTrackingTouch(VerticalSeekBar vBar);

这个接口主要是为外部提供监听。多说无益,大家看源代码明白一点。

import java.lang.reflect.Field;  
import java.lang.reflect.Method;  
import android.content.Context;  
import android.graphics.Canvas;  
import android.graphics.Rect;  
import android.graphics.drawable.Drawable;  
import android.util.AttributeSet;  
import android.util.Log;  
import android.view.MotionEvent;  
import android.view.View;  
import android.widget.AbsSeekBar;  
import android.widget.SeekBar;  
  
  
public class VerticalSeekBar extends AbsSeekBar {   
  
    private int height = -1;  
    private int width = -1;  
    public interface OnSeekBarChangeListener  
    {  
        public void onProgressChanged(VerticalSeekBar vBar, int progress,boolean fromUser);  
        public void onStartTrackingTouch(VerticalSeekBar vBar);  
        public void onStopTrackingTouch(VerticalSeekBar vBar);  
    }  
      
    private OnSeekBarChangeListener mOnSeekBarChangeListener;  
    public VerticalSeekBar(Context context)  
    {  
        this(context, null);  
    }  
      
    public VerticalSeekBar(Context context, AttributeSet attrs)  
    {  
        this(context, attrs, android.R.attr.seekBarStyle);  
    }  
      
    public VerticalSeekBar(Context context, AttributeSet attrs, int defstyle)  
    {  
        super(context, attrs, defstyle);  
    }  
      
    public void setOnSeekBarChangeListener(OnSeekBarChangeListener l)  
    {  
        mOnSeekBarChangeListener = l;  
    }  
      
    void onStartTrackingTouch()  
    {  
        if (mOnSeekBarChangeListener != null)  
        {  
            mOnSeekBarChangeListener.onStartTrackingTouch(this);  
        }  
    }  
      
    void onStopTrackingTouch()  
    {  
        if (mOnSeekBarChangeListener != null)  
        {  
            mOnSeekBarChangeListener.onStopTrackingTouch(this);  
        }  
    }  
      
    void onProgressRefresh(float scale, boolean fromUser)  
    {  
        Drawable thumb = null;  
        try  
        {  
            Field mThumb_f = this.getClass().getSuperclass().getDeclaredField("mThumb");  
            mThumb_f.setAccessible(true);  
            thumb = (Drawable)mThumb_f.get(this);  
        }  
        catch (Exception e)  
        {  
            e.printStackTrace();  
        }  
  
        setThumbPos(getWidth(), thumb, scale, Integer.MIN_VALUE);  
          
        invalidate();  
          
        if (mOnSeekBarChangeListener != null) {  
            mOnSeekBarChangeListener.onProgressChanged(this, getProgress(), fromUser);  
        }  
    }  
      
    private void setThumbPos(int w, Drawable thumb, float scale, int gap)  
    {  
        int available = 0;  
        try  
        {  
  
            int up = getPaddingTop();  
            int bottom = getPaddingBottom();  
              
            available = getHeight() - up - bottom;  
            int thumbWidth = thumb.getIntrinsicWidth();  
            int thumbHeight = thumb.getIntrinsicHeight();  
            available -= thumbWidth;  
              
            //The extra space for the thumb to move on the track  
            available += getThumbOffset() * 2;  
              
            int thumbPos = (int) (scale * available);  
  
            int topBound, bottomBound;  
            if (gap == Integer.MIN_VALUE) {  
                Rect oldBounds = thumb.getBounds();  
                topBound = oldBounds.top;  
                bottomBound = oldBounds.bottom;  
            } else {  
                topBound = gap;  
                bottomBound = gap + thumbHeight;  
            }  
            // Canvas will be translated, so 0,0 is where we start drawing  
            thumb.setBounds(thumbPos, topBound, thumbPos + thumbWidth, bottomBound);      
        }  
        catch (Exception e)  
        {  
            e.printStackTrace();  
        }  
  
    }  
      
     protected synchronized void onMeasure(int widthMeasureSpec, int heightMeasureSpec)  
     {       
         width = 30;  
         height = View.MeasureSpec.getSize(heightMeasureSpec);  
   
         this.setMeasuredDimension(width, height);   
     }   
      
    protected void onDraw(Canvas c)  
    {  
        c.rotate(-90);  
        c.translate(-height,0);   
        super.onDraw(c);  
    }  
      
    protected void onSizeChanged(int w, int h, int oldw, int oldh)  
    {       
        super.onSizeChanged(h, w, oldw, oldh);   
    }   
      
    @Override  
    public boolean onTouchEvent(MotionEvent event)  
    {  
          
        boolean mIsUserSeekable=true;  
        try  
        {  
            Field mIsUserSeekable_f = this.getClass().getSuperclass().getDeclaredField("mIsUserSeekable");  
            mIsUserSeekable_f.setAccessible(true);  
  
            mIsUserSeekable = mIsUserSeekable_f.getBoolean(this);  
        }  
        catch (Exception e1)  
        {  
            e1.printStackTrace();  
        }  
          
        if (!mIsUserSeekable || !isEnabled()) {  
            return false;  
        }  
          
        switch (event.getAction()) {  
            case MotionEvent.ACTION_DOWN:  
                setPressed(true);  
                onStartTrackingTouch();  
                trackTouchEvent(event);  
                break;  
                  
            case MotionEvent.ACTION_MOVE:  
                trackTouchEvent(event);  
                Method attemptClaimDrag;  
                try  
                {  
                    attemptClaimDrag = this.getClass().getSuperclass().getDeclaredMethod("attemptClaimDrag");  
                    attemptClaimDrag.setAccessible(true);  
                    attemptClaimDrag.invoke(this);  
                }  
                catch (Exception e)  
                {  
                    e.printStackTrace();  
                }  
                break;  
                  
            case MotionEvent.ACTION_UP:  
                trackTouchEvent(event);  
                onStopTrackingTouch();  
                setPressed(false);  
                // 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;  
                  
            case MotionEvent.ACTION_CANCEL:  
                onStopTrackingTouch();  
                setPressed(false);  
                invalidate(); // see above explanation  
                break;  
        }  
        return true;  
    }  
      
    protected void trackTouchEvent(MotionEvent event)  
    {  
          
        final int height = getHeight();  
        final int available = height - getPaddingLeft() - getPaddingRight();  
        int y = (int)(height - event.getY());  
        float scale;  
        float progress = 0;  
        if (y < getPaddingLeft()) {  
            scale = 0.0f;  
        } else if (y > height - getPaddingRight()) {  
            scale = 1.0f;  
        } else {  
            scale = (float)(y - getPaddingLeft()) / (float)available;  
            float mTouchProgressOffset = 0.0f;  
            try  
            {  
                Field mTouchProgressOffset_f = this.getClass().getSuperclass().getDeclaredField("mTouchProgressOffset");  
                mTouchProgressOffset_f.setAccessible(true);  
                mTouchProgressOffset = mTouchProgressOffset_f.getFloat(this);  
            }  
            catch(Exception e)  
            {  
                e.printStackTrace();  
            }  
            progress = mTouchProgressOffset;  
        }  
          
        final int max = getMax();  
        progress += scale * max;  
          
        try  
        {  
            Method setProgress = this.getClass().getSuperclass().getSuperclass().getDeclaredMethod("setProgress", int.class,boolean.class);  
            setProgress.setAccessible(true);  
            setProgress.invoke(this, (int)progress, true);  
        }  
        catch(Exception e)  
        {  
            e.printStackTrace();  
        }  
    }  
}  

[转载链接地址]http://blog.csdn.net/failure01/article/details/8577675