Android自定义View仿QQ侧滑菜单的实现代码

public class SideslipView extends HorizontalScrollView {
  private int mScreenWidth;//屏幕宽度
  private int mMenuLeftPadding;
  private int mBluetoothWidth;//菜单的宽度
  private int mHalfMenuWidth;
  View home;
  View bluetooth;
  protected boolean isOpen;
  protected boolean isFirst = true;
  public SideslipView(Context context) {
    // super 改 this
    this(context, null);
  }
  public SideslipView(Context context, AttributeSet attrs) {
    // super 改 this
    this(context, attrs, 0);
  }
  public SideslipView(Context context, AttributeSet attrs, int defStyleAttr) {
    super(context, attrs, defStyleAttr);
    //测量屏幕宽度
    WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
    DisplayMetrics metrics = new DisplayMetrics();
    wm.getDefaultDisplay().getMetrics(metrics);
    mScreenWidth = metrics.widthPixels;
    // mScreenWidth = context.getResources().getDisplayMetrics().widthPixels;
    Log.e("TAG", "MyScrollView: mScreenWidth" + mScreenWidth);
    //获取 自定义的属性值
    TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.MyScrollView);
    int n = a.length();
    for (int i = 0; i = mHalfMenuWidth) {
          Log.e("TAG", "====");
          this.smoothScrollTo(mBluetoothWidth, 0);
          isOpen = true;
        } else {
          this.smoothScrollTo(0, 0);
          isOpen = false;
        }
        //必须消耗事件
        return true;
    }
    return super.onTouchEvent(ev);
    //return true;
  }
  /**
   * 打开菜单栏
   */
  protected void openMenu() {
    if (isOpen)
      return;
    this.smoothScrollTo(mBluetoothWidth, 0);
    isOpen = true;
  }
  /**
   * 关闭菜单栏
   */
  protected void closeMenu() {
    if (!isOpen)
      return;
    this.smoothScrollTo(0, 0);
    isOpen = false;
  }
  /**
   * 按钮切换菜单
   */
  public void toggleMenu() {
    if (isOpen)
      closeMenu();
    else
      openMenu();
  }
  @Override
  protected void onScrollChanged(int l, int t, int oldl, int oldt) {
    super.onScrollChanged(l, t, oldl, oldt);
//此处 l 起始值为零（没有偏移）
    Log.e("TAG", "l=" + l + " t=" + t);
    Log.e("TAG", "oldl=" + oldl + " oldt=" + oldt);
    // scale 在 1 到 0 之间
    float scale = l * 1.0f / mBluetoothWidth;
    /**
     * 抽屉式侧滑
     * scaleLeft 从默认偏移量到偏移量 为零
     *实现
     * */
    float scaleLeft = 0.4f - 0.4f * scale;
    /**设置 X 轴方向的偏移量**/
    ViewHelper.setTranslationX(bluetooth, -(mBluetoothWidth * scaleLeft));
    Log.e("TAG", "mBluetoothWidth+" + mBluetoothWidth);
    Log.e("TAG", "=============" + mBluetoothWidth * scale + "scale" + scale);
/*
    *//**设置缩放时的 轴心点**//*
    //此处轴心为右边界的中点
    ViewHelper.setPivotY(home, mScreenWidth);
    ViewHelper.setPivotX(home, home.getHeight() / 2);
    *//**设置 ＸＹ轴方向的 缩放动画(从 1 到 0.9)**//*
    float pivoXY = 1 - 0.4f * scale;
    ViewHelper.setScaleX(home, pivoXY);
    ViewHelper.setScaleY(home, pivoXY);*/
/*
    *//**设置透明度**//*
    //从 1 到 0.6；
    float alpha = 1 - 0.4f * scale;
    ViewHelper.setAlpha(home, alpha);*/
  }
}