Android自定义View实现等级滑动条的实例

 Android自定义View实现等级滑动条的实例

实现效果图：

思路：

首先绘制直线，然后等分直线绘制点；

绘制点的时候把X值存到集合中。

然后绘制背景图片，以及图片上的数字。

点击事件down的时候，换小图片为大图片。move的时候跟随手指移动。

up的时候根据此时的X计算最近的集合中的点，然后自动吸附回去。

1，自定义属性

<?xml version="1.0" encoding="utf-8"?>
<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>

然后获取属性：

 /**
     * 获得我们所定义的自定义样式属性
     */
    TypedArray a = context.getTheme().obtainStyledAttributes(attrs, R.styleable.BeautySeekBarView, defStyleAttr, 0);
    //等级数量即点的个数
    valueCountent=a.getInteger(R.styleable.BeautySeekBarView_valueCountent, 5);
    //点的颜色
    pointColor = a.getColor(R.styleable.BeautySeekBarView_pointColor, Color.WHITE);
    //线的颜色
    lineColor = a.getColor(R.styleable.BeautySeekBarView_lineColor, Color.WHITE);
    //小图片
    smallPic=a.getResourceId(R.styleable.BeautySeekBarView_smallPic, R.drawable.ic_launcher);
    //滑动过程中的大图片
    bigPic=a.getResourceId(R.styleable.BeautySeekBarView_bigPic, R.drawable.ic_launcher);
    //控件的内边距
    viewPadding=a.getDimensionPixelSize(R.styleable.BeautySeekBarView_padding, (int) TypedValue.applyDimension(
            TypedValue.COMPLEX_UNIT_SP, 16, getResources().getDisplayMetrics()));

    a.recycle();

2.绘制

@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); //绘制直线

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

      if(pointList!=null && pointList.size()<valueCountent){
      pointList.add(PointX);//把每个点都放入集合中；
      }
    }
    sePoolTH.release();
    canvas.drawBitmap(mBitmap, bitmapPointX-bitmapWidth/2, PointY-bitmapHeight/2, null);//绘制拖动的图片
    canvas.drawText(""+index, bitmapPointX, (getHeight() - fontMetrics.ascent - fontMetrics.descent) / 2, textPaint); //绘制文字
  }

全部代码如下

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);//信号量，解决并发问题

  private int valueCountent;//等级点的数量
  private int pointColor;
  private int lineColor;
  private Bitmap mBitmap;
  private int bitmapWidth;
  private int bitmapHeight;
  private float bitmapPointX;
  private ArrayList<Float> pointList;//储存画出的点的point值
  private HashMap<Float, Float> mHashMap;////把差值和listX当做键值对保存起来，便于后期找出
  private int index=1;//索引
  private float mListX;//移动后最小的点
  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);
     /**
     * 获得我们所定义的自定义样式属性
     */
    TypedArray a = context.getTheme().obtainStyledAttributes(attrs, R.styleable.BeautySeekBarView, defStyleAttr, 0);
    //等级数量即点的个数
    valueCountent=a.getInteger(R.styleable.BeautySeekBarView_valueCountent, 5);
    //点的颜色
    pointColor = a.getColor(R.styleable.BeautySeekBarView_pointColor, Color.WHITE);
    //线的颜色
    lineColor = a.getColor(R.styleable.BeautySeekBarView_lineColor, Color.WHITE);
    //小图片
    smallPic=a.getResourceId(R.styleable.BeautySeekBarView_smallPic, R.drawable.ic_launcher);
    //滑动过程中的大图片
    bigPic=a.getResourceId(R.styleable.BeautySeekBarView_bigPic, R.drawable.ic_launcher);
    //控件的内边距
    viewPadding=a.getDimensionPixelSize(R.styleable.BeautySeekBarView_padding, (int) TypedValue.applyDimension(
            TypedValue.COMPLEX_UNIT_SP, 16, getResources().getDisplayMetrics()));

    a.recycle();    

    initData();//初始化数据
    initPaint();//初始化画笔
  }
  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); //绘制直线

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

      if(pointList!=null && pointList.size()<valueCountent){
      pointList.add(PointX);//把每个点都放入集合中；
      }
    }
    sePoolTH.release();
    canvas.drawBitmap(mBitmap, bitmapPointX-bitmapWidth/2, PointY-bitmapHeight/2, null);//绘制拖动的图片
    canvas.drawText(""+index, bitmapPointX, (getHeight() - fontMetrics.ascent - fontMetrics.descent) / 2, textPaint); //绘制文字
  }

  long startTime = 0;
  @Override
  public boolean onTouchEvent(MotionEvent event) {
        //获取手指的操作--》按下、移动、松开
        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，抬起时间过大才认为是拖动，要执行动画。
           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，抬起时间过大才认为是拖动，要执行动画。
          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当做键值对保存起来，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;
  }

  //当手指抬起后更新Bitmap的位置
  private void updateBitmapUI(float PointX2) {
    mListX=updateIndex(PointX2);
    //执行动画
    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();
  }

  //设置等级点的数量
  public void pointValueCountent(int countent){
    if(countent<2){
      valueCountent=2;
    }else{
      valueCountent=countent;
    }
    invalidate();
  }

  //设置默认位置
  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();

  }

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

}

外部调用：

XML：

 <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"/>

Java：

@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);
    }
  });
  }

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