如何在Android中利用View實(shí)現(xiàn)一個(gè)等級(jí)滑動(dòng)條功能

<&#63;xml version="1.0" encoding="utf-8"&#63;>
<resources>
   <declare-styleable name="BeautySeekBarView"> 
    <attr name="valueCountent" format="integer"/> 
     <attr name="padding" format="dimension"/>   
    <attr name="pointColor" format="color"/> 
    <attr name="lineColor" format="color"/>
    <attr name="smallPic" format="reference"/> 
    <attr name="bigPic" format="reference"/>  
  </declare-styleable> 
</resources>

 /** 
     * 獲得我們所定義的自定義樣式屬性 
     */ 
    TypedArray a = context.getTheme().obtainStyledAttributes(attrs, R.styleable.BeautySeekBarView, defStyleAttr, 0);
    //等級(jí)數(shù)量即點(diǎn)的個(gè)數(shù)
    valueCountent=a.getInteger(R.styleable.BeautySeekBarView_valueCountent, 5);
    //點(diǎn)的顏色
    pointColor = a.getColor(R.styleable.BeautySeekBarView_pointColor, Color.WHITE); 
    //線的顏色
    lineColor = a.getColor(R.styleable.BeautySeekBarView_lineColor, Color.WHITE);
    //小圖片
    smallPic=a.getResourceId(R.styleable.BeautySeekBarView_smallPic, R.drawable.ic_launcher);
    //滑動(dòng)過(guò)程中的大圖片
    bigPic=a.getResourceId(R.styleable.BeautySeekBarView_bigPic, R.drawable.ic_launcher);  
    //控件的內(nèi)邊距
    viewPadding=a.getDimensionPixelSize(R.styleable.BeautySeekBarView_padding, (int) TypedValue.applyDimension( 
            TypedValue.COMPLEX_UNIT_SP, 16, getResources().getDisplayMetrics()));

    a.recycle();    

@Override
  protected void onDraw(Canvas canvas) {
    // TODO Auto-generated method stub
    super.onDraw(canvas);

    float PointX = 0;
    float PointY=getHeight()/2;   
    canvas.drawLine(0+getPaddingLeft(),PointY, getWidth()-getPaddingRight(), PointY, linePaint); //繪制直線

    int averageLength =(getWidth()-getPaddingLeft()-getPaddingRight())/(valueCountent-1);
    for(int i=0;i<valueCountent;i++){
      PointX=i*averageLength+getPaddingLeft();
      canvas.drawPoint(PointX, PointY, pointPaint);//繪制點(diǎn)

      if(pointList!=null && pointList.size()<valueCountent){
      pointList.add(PointX);//把每個(gè)點(diǎn)都放入集合中；
      }      
    }
    sePoolTH.release();
    canvas.drawBitmap(mBitmap, bitmapPointX-bitmapWidth/2, PointY-bitmapHeight/2, null);//繪制拖動(dòng)的圖片 
    canvas.drawText(""+index, bitmapPointX, (getHeight() - fontMetrics.ascent - fontMetrics.descent) / 2, textPaint); //繪制文字
  }

import java.util.ArrayList;
import java.util.HashMap;
import java.util.concurrent.Semaphore;


import android.R.integer;
import android.animation.ValueAnimator;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Paint.FontMetricsInt;
import android.util.AttributeSet;
import android.util.Log;
import android.util.TypedValue;
import android.view.MotionEvent;
import android.view.View;

public class BeautySeekBarView extends View {

  private Semaphore sePoolTH=new Semaphore(0);//信號(hào)量，解決并發(fā)問(wèn)題

  private int valueCountent;//等級(jí)點(diǎn)的數(shù)量
  private int pointColor;
  private int lineColor;
  private Bitmap mBitmap;
  private int bitmapWidth;
  private int bitmapHeight;
  private float bitmapPointX;
  private ArrayList<Float> pointList;//儲(chǔ)存畫(huà)出的點(diǎn)的point值
  private HashMap<Float, Float> mHashMap;////把差值和listX當(dāng)做鍵值對(duì)保存起來(lái)，便于后期找出
  private int index=1;//索引
  private float mListX;//移動(dòng)后最小的點(diǎn)
  private int smallPic;
  private int bigPic;
  private int viewPadding; 

  private Paint pointPaint;
  private Paint linePaint;
  private Paint textPaint;
  private FontMetricsInt fontMetrics;


  public BeautySeekBarView(Context context) {
    this(context,null);   
  }
  public BeautySeekBarView(Context context, AttributeSet attrs) {
    this(context, attrs,0);   
  }
  public BeautySeekBarView(Context context, AttributeSet attrs, int defStyleAttr) {
    super(context, attrs, defStyleAttr);        
     /** 
     * 獲得我們所定義的自定義樣式屬性 
     */ 
    TypedArray a = context.getTheme().obtainStyledAttributes(attrs, R.styleable.BeautySeekBarView, defStyleAttr, 0);
    //等級(jí)數(shù)量即點(diǎn)的個(gè)數(shù)
    valueCountent=a.getInteger(R.styleable.BeautySeekBarView_valueCountent, 5);
    //點(diǎn)的顏色
    pointColor = a.getColor(R.styleable.BeautySeekBarView_pointColor, Color.WHITE); 
    //線的顏色
    lineColor = a.getColor(R.styleable.BeautySeekBarView_lineColor, Color.WHITE);
    //小圖片
    smallPic=a.getResourceId(R.styleable.BeautySeekBarView_smallPic, R.drawable.ic_launcher);
    //滑動(dòng)過(guò)程中的大圖片
    bigPic=a.getResourceId(R.styleable.BeautySeekBarView_bigPic, R.drawable.ic_launcher);  
    //控件的內(nèi)邊距
    viewPadding=a.getDimensionPixelSize(R.styleable.BeautySeekBarView_padding, (int) TypedValue.applyDimension( 
            TypedValue.COMPLEX_UNIT_SP, 16, getResources().getDisplayMetrics()));

    a.recycle();    

    initData();//初始化數(shù)據(jù) 
    initPaint();//初始化畫(huà)筆  
  }
  public void initData() {
//   valueCountent=7;
//   pointColor=Color.WHITE;
//   lineColor=Color.WHITE;     
//   setBackgroundColor(Color.BLACK);    
    setPadding(viewPadding, viewPadding, viewPadding, viewPadding);
    bitmapPointX=getPaddingLeft();
    mBitmap=BitmapFactory.decodeResource(getResources(), smallPic);
    bitmapWidth=mBitmap.getWidth();
    bitmapHeight=mBitmap.getHeight();
    pointList=new ArrayList<Float>();
    mHashMap=new HashMap<Float, Float>();
  }
  public void initPaint() {
    pointPaint=new Paint();
    pointPaint.setColor(pointColor);
    pointPaint.setStyle(Paint.Style.FILL);
    pointPaint.setStrokeWidth(10);
    pointPaint.setStrokeJoin(Paint.Join.ROUND);
    pointPaint.setStrokeCap(Paint.Cap.ROUND);
    pointPaint.setAntiAlias(true); 

    linePaint=new Paint();
    linePaint.setColor(lineColor);
    linePaint.setStyle(Paint.Style.STROKE);
    linePaint.setStrokeWidth(4);
    linePaint.setAntiAlias(true); 

    textPaint=new Paint();
    textPaint.setStrokeWidth(3);  
    textPaint.setTextSize(24);  
    textPaint.setColor(Color.WHITE); 
    textPaint.setTextAlign(Paint.Align.CENTER);    
    fontMetrics = textPaint.getFontMetricsInt(); 
    textPaint.setAntiAlias(true); 

  }

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
  // TODO Auto-generated method stub
  super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}

  @Override
  protected void onDraw(Canvas canvas) {
    // TODO Auto-generated method stub
    super.onDraw(canvas);

    float PointX = 0;
    float PointY=getHeight()/2;   
    canvas.drawLine(0+getPaddingLeft(),PointY, getWidth()-getPaddingRight(), PointY, linePaint); //繪制直線

    int averageLength =(getWidth()-getPaddingLeft()-getPaddingRight())/(valueCountent-1);
    for(int i=0;i<valueCountent;i++){
      PointX=i*averageLength+getPaddingLeft();
      canvas.drawPoint(PointX, PointY, pointPaint);//繪制點(diǎn)

      if(pointList!=null && pointList.size()<valueCountent){
      pointList.add(PointX);//把每個(gè)點(diǎn)都放入集合中；
      }      
    }
    sePoolTH.release();
    canvas.drawBitmap(mBitmap, bitmapPointX-bitmapWidth/2, PointY-bitmapHeight/2, null);//繪制拖動(dòng)的圖片 
    canvas.drawText(""+index, bitmapPointX, (getHeight() - fontMetrics.ascent - fontMetrics.descent) / 2, textPaint); //繪制文字
  }

  long startTime = 0;
  @Override
  public boolean onTouchEvent(MotionEvent event) {       
        //獲取手指的操作--》按下、移動(dòng)、松開(kāi)
        int action = event.getAction();
        switch (action) {
        case MotionEvent.ACTION_DOWN:  
          startTime=System.currentTimeMillis();
          mBitmap=BitmapFactory.decodeResource(getResources(), bigPic);
          bitmapWidth=mBitmap.getWidth();
          bitmapHeight=mBitmap.getHeight();
          textPaint.setTextSize(30); 
          //invalidate();
          break;       
        case MotionEvent.ACTION_MOVE:        
          long endTimeMove=System.currentTimeMillis();        
          if(endTimeMove-startTime>100){//如果按下，抬起時(shí)間過(guò)大才認(rèn)為是拖動(dòng)，要執(zhí)行動(dòng)畫(huà)。
           bitmapPointX=event.getX();
           updateIndex(bitmapPointX);
           invalidate();
          }
          break;
        case MotionEvent.ACTION_UP:
          long endTime=System.currentTimeMillis();
          bitmapPointX=event.getX();
          mBitmap=BitmapFactory.decodeResource(getResources(),smallPic);
          bitmapWidth=mBitmap.getWidth();
          bitmapHeight=mBitmap.getHeight();
          textPaint.setTextSize(24);             
          if(endTime-startTime>200){//如果按下，抬起時(shí)間過(guò)大才認(rèn)為是拖動(dòng)，要執(zhí)行動(dòng)畫(huà)。
          updateBitmapUI(bitmapPointX);
          }else{           
            bitmapPointX=updateIndex(bitmapPointX);
            invalidate();
          }
          startTime = 0;
          break;
        }
        return true;
  }
  //更新索引
  public float updateIndex(float pointX){
    float lastValue=100000;
    float currentValue=0;
    float minValue=0;
     for(float listX:pointList){
       currentValue= Math.abs(pointX-listX);
       mHashMap.put(currentValue, listX);//把差值和listX當(dāng)做鍵值對(duì)保存起來(lái)，便于后期找出
       minValue=Math.min(lastValue,currentValue);
       lastValue=minValue;
      }      
    if(mHashMap.containsKey(minValue)){
      mListX=mHashMap.get(minValue);
    }else{
      Log.e("BeautySeekBarView", "updateBitmapUI--->mHashMap.containsKey(minValue) is null");
      return -1;
    } 
    if(pointList.contains(mListX)){
    index=pointList.indexOf(mListX)+1;
    if(mListener!=null){
      mListener.getIndex(index);
    }
    }else{
      Log.e("BeautySeekBarView", "updateBitmapUI--->pointList.contains(mListX) is null");
        return -1;
    }
    return mListX;
  }

  //當(dāng)手指抬起后更新Bitmap的位置
  private void updateBitmapUI(float PointX2) {
    mListX=updateIndex(PointX2);
    //執(zhí)行動(dòng)畫(huà)   
    ValueAnimator anim = ValueAnimator.ofFloat(PointX2, mListX);
    anim.setDuration(50);
    anim.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
      @Override
      public void onAnimationUpdate(ValueAnimator animation) {
        bitmapPointX =(Float) animation.getAnimatedValue();
        invalidate();
      }
    });
    anim.start();
  }

  //設(shè)置等級(jí)點(diǎn)的數(shù)量
  public void pointValueCountent(int countent){
    if(countent<2){
      valueCountent=2;
    }else{
      valueCountent=countent;
    }
    invalidate();
  }

  //設(shè)置默認(rèn)位置
  public void setPointLocation(final int location){
    new Thread(new Runnable() {

      @Override
      public void run() {       
         try {
            sePoolTH.acquire();
          } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
          }    
          if(location>0&&pointList!=null&& !pointList.isEmpty()){
            bitmapPointX=pointList.get(location-1);
            postInvalidate();
          }

      }
    }).start();

  }

  //提供接口回調(diào)，獲取索引
  private indexListener mListener=null;
  public interface indexListener{
    void getIndex(int index);
  }
  public void setIndexListener(indexListener listener){
    mListener=listener;
  }

}

 <com.example.hello.BeautySeekBarView 
    android:id="@+id/myView"
    android:layout_centerVertical="true"
    android:layout_width="match_parent"
    android:layout_height="100dp"
    ws:padding="20dp"     
    ws:valueCountent="6"   
    ws:pointColor="#FFFFFF"
    ws:lineColor="#FFFFFF"
    ws:smallPic="@drawable/beauty_seekbar_point"
    ws:bigPic="@drawable/beauty_seekbar_point_big"/>

@Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);  
    setContentView(R.layout.activity_main);

   initView(); 

   beautySeekBarView.setPointLocation(2) ;
    //

  }

  private void initView() {
  mTextView=(TextView) findViewById(R.id.tv);
  beautySeekBarView=(BeautySeekBarView) findViewById(R.id.myView);
  beautySeekBarView.setIndexListener(new indexListener() {  
    @Override
    public void getIndex(int index) {
      mTextView.setText("index="+index); 
    }
  });
  }