Android手势操作示例(上/下/左/右的判断)

本文实例讲述了android手势操作方法。分享给大家供大家参考，具体如下：

android中提供了判断手势的接口，所以我们可以根据提供的api来实现各种各样的手势功能来提高手机应用的用户体验。

下面是我写的一段小demo：

gestureactivity.java

public class gestureactivity extends activity {
  private gesturedetector gesturedetector;
  private screen screen;
  @override
  public void oncreate(bundle savedinstancestate) {
    super.oncreate(savedinstancestate);
    setcontentview(r.layout.main);
    gesturedetector = new gesturedetector(this,ongesturelistener);
    //得到屏幕的大小
    screen = gestureutils.getscreenpix(this);
  }
  @override
  public boolean ontouchevent(motionevent event) {
    return gesturedetector.ontouchevent(event);
  }
  gesturedetector.ongesturelistener ongesturelistener = new gesturedetector.simpleongesturelistener(){
    @override
    public boolean onfling(motionevent e1, motionevent e2, float velocityx,
        float velocityy) {
      float x = e2.getx() - e1.getx();
      float y = e2.gety() - e1.gety();
      //限制必须得划过屏幕的1/3才能算划过
      float x_limit = screen.widthpixels / 3;
      float y_limit = screen.heightpixels / 3;
      float x_abs = math.abs(x);
      float y_abs = math.abs(y);
      if(x_abs >= y_abs){
        //gesture left or right
        if(x > x_limit || x < -x_limit){
          if(x>0){
            //right
            show("right");
          }else if(x
            //left
            show("left");
          }
        }
      }else{
        //gesture down or up
        if(y > y_limit || y < -y_limit){
          if(y>0){
            //down
            show("down");
          }else if(y
            //up
            show("up");
          }
        }
      }
      return true;
    }
  };
  private void show(string value){
    toast.maketext(this, value, toast.length_short).show();
  }
}

gestureutils.java

public class gestureutils {
  //获取屏幕的大小
  public static screen getscreenpix(context context) {
    displaymetrics dm = new displaymetrics();
    windowmanager windowmanager = (windowmanager) context.getsystemservice(context.window_service);
    windowmanager.getdefaultdisplay().getmetrics(dm);
    return new screen(dm.widthpixels,dm.heightpixels);
  }
  public static class screen{
    public int widthpixels;
    public int heightpixels;
    public screen(){
    }
    public screen(int widthpixels,int heightpixels){
      this.widthpixels=widthpixels;
      this.heightpixels=heightpixels;
    }
    @override
    public string tostring() {
      return "("+widthpixels+","+heightpixels+")";
    }
  }
}

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希望本文所述对大家android程序设计有所帮助。