Android 实现双击退出的功能

实现android双击后退键退出当前app功能

实现该功能基本思路是，

1， 监听后退键 ， 比较两次后退间隔 ， 低于两秒则出发退出

2， 退出当前app

我选择在基类中baseactivity 中设置监听，代码如下：

 public void onbackpressed() {

    //preferences 中获取是否双击退出
    boolean isdoubleclick = true;
    //baseapplication.get("ifdoubleclickedback", true);

    if (isdoubleclick) {
      long curtime = systemclock.uptimemillis();
      if ((curtime - mbackpressedtime) < (2 * 1000)) {
        finish();
        //activity栈管理
        appmanager.getappmanager().appexit();
      } else {
        mbackpressedtime = curtime;
        toast.maketext(this, "再次点击退出", toast.length_short).show();
      }
    } else {
      finish();
    }

  }

在退出当前app中，参考开源中国，封装了activity栈

实例代码：

public class appmanager {
  private static stack<activity> activitystack;
  private static appmanager instance;

  private appmanager() {
  }

  /**
   * 单一实例
   */
  public static appmanager getappmanager() {
    if (instance == null) {
      instance = new appmanager();
    }

    if (activitystack == null) {
      activitystack = new stack<activity>();
    }

    return instance;
  }

  /**
   * 获取指定的activity
   *
   * @author kymjs
   */
  public static activity getactivity(class<?> cls) {
    if (activitystack != null)
      for (activity activity : activitystack) {
        if (activity.getclass().equals(cls)) {
          return activity;
        }
      }
    return null;
  }

  /**
   * 添加activity到堆栈
   */
  public void addactivity(activity activity) {
    activitystack.add(activity);
  }

  /**
   * 获取当前activity（堆栈中最后一个压入的）
   */
  public activity currentactivity() {
    activity activity = activitystack.lastelement();
    return activity;
  }

  /**
   * 结束当前activity（堆栈中最后一个压入的）
   */
  public void finishactivity() {
    activity activity = activitystack.lastelement();
    finishactivity(activity);
  }

  /**
   * 结束指定的activity
   */
  public void finishactivity(activity activity) {
    if (activity != null && activitystack.contains(activity)) {
      activitystack.remove(activity);
      activity.finish();
    }
  }

  /**
   * 结束指定的activity
   */
  public void removeactivity(activity activity) {
    if (activity != null && activitystack.contains(activity)) {
      activitystack.remove(activity);
    }
  }

  /**
   * 结束指定类名的activity
   */
  public void finishactivity(class<?> cls) {
    for (activity activity : activitystack) {
      if (activity.getclass().equals(cls)) {
        finishactivity(activity);
        break;
      }
    }
  }

  /**
   * 结束所有activity
   */
  public void finishallactivity() {
    for (int i = 0, size = activitystack.size(); i < size; i++) {
      if (null != activitystack.get(i)) {
        finishactivity(activitystack.get(i));
      }
    }
    activitystack.clear();
  }

  /**
   * 退出应用程序
   */
  public void appexit() {
    try {
      finishallactivity();
      // system.exit(0);
    } catch (exception e) {
    }
  }
}

思路就是在每次activity 压入activity栈中管理

在退出时遍历栈，挨个finish

希望本文所述对大家的android程序设计有所帮助。