<?xml version="1.0" encoding="utf-8"?>
<resources>
  <declare-styleable name="switchView_attrs">
    <attr name="background" format="reference"></attr>
    <attr name="slide" format="reference"></attr>
  </declare-styleable>  
</resources>

public SwitchView(Context context, AttributeSet attrs) {
    super(context, attrs);
    //拿到自定義屬性
    TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.switchView_attrs);
    //拿到自定義字段的值
    Drawable switchBackground = ta.getDrawable(R.styleable.switchView_attrs_background);
    Drawable switchView_slide = ta.getDrawable(R.styleable.switchView_attrs_slide);
    //把值設(shè)置到相應(yīng)組件上
    backgroundBitmap = convertDrawable2BitmapSimple(switchBackground);
    switchSlide = convertDrawable2BitmapSimple(switchView_slide);
  }

//將Drawable轉(zhuǎn)成Bitmap
  public Bitmap convertDrawable2BitmapSimple(Drawable drawable) {
    BitmapDrawable bd= (BitmapDrawable)drawable;
    return bd.getBitmap();
  }

//控制控件的大小
  @Override
  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    if (backgroundBitmap != null) {
      //控件大小設(shè)置為背景的大小
      setMeasuredDimension(backgroundBitmap.getWidth(), backgroundBitmap.getHeight());
    }else {
      super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }
  }

/** 
   * switchView開關(guān)監(jiān)聽接口
   * 
   * */
  interface OnSwitchChangedListener {
    public void onSwitchChange(boolean isOpen);
  }
  /** 
   * 設(shè)置 switchView狀態(tài)監(jiān)聽 
   * */
  public void setOnChangeListener(OnSwitchChangedListener listener) {
    switchListener = listener;
  }

<com.example.custom.SwitchView
    minguo:background="@drawable/switch_background"
    minguo:slide="@drawable/slide_button_background"
    android:id="@+id/switchView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"/>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:minguo="http://schemas.android.com/apk/res/com.example.custom"
  xmlns:tools="http://schemas.android.com/tools"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  tools:context="com.example.custom.MainActivity" >
  <com.example.custom.SwitchView
    minguo:background="@drawable/switch_background"
    minguo:slide="@drawable/slide_button_background"
    android:id="@+id/switchView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"/>
</LinearLayout>

/**
 * 自定義開關(guān)按鈕
 * @author Administrator
 *
 */
public class SwitchView extends View {
  //背景圖片和滑塊圖片
  private Bitmap backgroundBitmap,switchSlide;
  //畫筆
  private Paint paint;
  //得到的x坐標(biāo)（點(diǎn)擊、移動(dòng)、抬起）
  private float currentX;
  //判斷開關(guān)是否打開的標(biāo)記位
  private boolean isOpen = false;
  //開關(guān)打開與關(guān)閉的監(jiān)聽器
  private OnSwitchChangedListener switchListener;
  //滑塊的四種狀態(tài)
  public static final int STATE_DOWN = 1; //按下的時(shí)候
  public static final int STATE_MOVE = 2; //移動(dòng)的時(shí)候
  public static final int STATE_UP = 3;  //抬起的時(shí)候
  public static final int STATE_NONE = 0; //空的時(shí)候（即什么都沒干的時(shí)候）
  //標(biāo)記狀態(tài)（默認(rèn)為空狀態(tài)）
  private int state = STATE_NONE;
  public SwitchView(Context context) {
    super(context,null);
  }
  public SwitchView(Context context, AttributeSet attrs) {
    super(context, attrs);
    //拿到自定義屬性
    TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.switchView_attrs);
    //拿到自定義字段的值
    Drawable switchBackground = ta.getDrawable(R.styleable.switchView_attrs_background);
    Drawable switchView_slide = ta.getDrawable(R.styleable.switchView_attrs_slide);
    //把值設(shè)置到相應(yīng)組件上
    backgroundBitmap = convertDrawable2BitmapSimple(switchBackground);
    switchSlide = convertDrawable2BitmapSimple(switchView_slide);
  }
  //將Drawable轉(zhuǎn)成Bitmap
  public Bitmap convertDrawable2BitmapSimple(Drawable drawable) {
    BitmapDrawable bd = (BitmapDrawable)drawable;
    return bd.getBitmap();
  }
  //控制控件的大小
  @Override
  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    if (backgroundBitmap != null) {
      //控件大小設(shè)置為背景的大小
      setMeasuredDimension(backgroundBitmap.getWidth(), backgroundBitmap.getHeight());
    }else {
      super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }
  }
  //繪制控件的樣式
  @Override
  protected void onDraw(Canvas canvas) {
    //背景為空的時(shí)候才將背景繪制
    if (backgroundBitmap != null) {
      paint = new Paint();
      //第一個(gè)參數(shù)表示需要畫的Bitmap
      //第二個(gè)參數(shù)表示Bitmap左邊離控件的左邊距
      //第三個(gè)參數(shù)表示Bitmap上邊離控件的上邊距
      //第四個(gè)參數(shù)表示畫筆
      canvas.drawBitmap(backgroundBitmap, 0, 0, paint);
    }
    switch (state) {
    case STATE_DOWN:    //按下和移動(dòng)的觸發(fā)事件都一樣，都是將滑塊移動(dòng)
    case STATE_MOVE:
      //當(dāng)按下或移動(dòng)的坐標(biāo)大于滑塊寬度一半時(shí)將滑塊右移
      if (currentX > switchSlide.getWidth()/2f) {
        //讓滑塊向右滑動(dòng)（重新繪制滑塊的位置）
        float left = currentX - switchSlide.getWidth()/2f;
        //防止滑塊移至背景外面，最大是滑塊右邊和背景右邊對(duì)齊（即最大離左邊為背景寬度-滑塊寬度）
        float maxLeft = backgroundBitmap.getWidth() - switchSlide.getWidth();
        if (left > maxLeft) {
          left = maxLeft;
        }
        canvas.drawBitmap(switchSlide, left, 0, paint);
      //當(dāng)按下或移動(dòng)的坐標(biāo)小于滑塊寬度一半時(shí)滑塊不動(dòng)
      }else if (currentX < switchSlide.getWidth()/2f) {
        //讓滑塊不動(dòng)就可以了
        canvas.drawBitmap(switchSlide, 0, 0, paint);
      }
      break;
    case STATE_NONE:    //空或抬起的時(shí)候?qū)⒒瑝K至于左邊或右邊
    case STATE_UP:
      //如果是打開的將滑塊移動(dòng)至右邊，并將打開狀態(tài)傳至監(jiān)聽器
      if (isOpen) {
        if (switchListener != null) {
          switchListener.onSwitchChange(true);
        }
        canvas.drawBitmap(switchSlide, 
            backgroundBitmap.getWidth() - switchSlide.getWidth(), 0, paint);
      //如果是關(guān)閉的將滑塊至于左邊，并將關(guān)閉狀態(tài)傳至監(jiān)聽器
      }else {
        if (switchListener != null) {
          switchListener.onSwitchChange(false);
        }
        canvas.drawBitmap(switchSlide, 0, 0, paint);
      }
      break;
    default:
      break;
    }
  }
  @Override
  public boolean onTouchEvent(MotionEvent event) {
    switch (event.getAction()) {
    case MotionEvent.ACTION_DOWN:
      currentX = event.getX();
      //將標(biāo)記位修改成按下的狀態(tài)
      state = STATE_DOWN;
      //通知系統(tǒng)重新繪制界面
      invalidate();//在主線程
//     postInvalidate();//在子線程
      break;
    case MotionEvent.ACTION_MOVE:
      currentX = event.getX();
      //將標(biāo)記位修改為移動(dòng)狀態(tài)
      state = STATE_MOVE;
      invalidate();
      break;
    case MotionEvent.ACTION_UP:
      currentX = event.getX();
      //將標(biāo)記為修改為抬起狀態(tài)
      state = STATE_UP;
      //抬起的坐標(biāo)大于背景寬度一半的時(shí)候設(shè)為打開狀態(tài)
      if (currentX > backgroundBitmap.getWidth()/2f) {
        //滑塊在右邊,開啟
        isOpen = true;
      //抬起的坐標(biāo)小于背景寬度坐標(biāo)一 半的時(shí)候設(shè)為關(guān)閉狀態(tài)
      }else if (currentX < backgroundBitmap.getWidth()) {
        //滑塊在左邊,關(guān)閉
        isOpen = false;

      }
      invalidate();
      break;
    }
    return true;
  }
  /** 
   * switchView開關(guān)監(jiān)聽接口
   * 
   * */
  interface OnSwitchChangedListener {
    public void onSwitchChange(boolean isOpen);
  }
  /** 
   * 設(shè)置 switchView狀態(tài)監(jiān)聽 
   * */
  public void setOnChangeListener(OnSwitchChangedListener listener) {
    switchListener = listener;
  }
}

public class MainActivity extends Activity {

  private SwitchView switchView;
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    switchView = (SwitchView) findViewById(R.id.switchView);
    switchView.setOnChangeListener(new OnSwitchChangedListener() {
      @Override
      public void onSwitchChange(boolean isOpen) {
        if (isOpen) {
          //打開開關(guān)的時(shí)候的邏輯
          Toast.makeText(MainActivity.this, "開關(guān)打開了", Toast.LENGTH_LONG).show();
        }else {
          //關(guān)閉開關(guān)的時(shí)候的邏輯
          Toast.makeText(MainActivity.this, "開關(guān)關(guān)閉了", Toast.LENGTH_LONG).show();
        }
      }
    });
  }
}