Android 全局Dialog的简单实现方法

/**
 * Activity管理类
 * @author Donkor
 */
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();
    }
    return instance;
  }
  /**
   * 添加Activity到堆栈
   */
  public void addActivity(Activity activity){
    if(activityStack==null){
      activityStack=new Stack<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();
    if(activity!=null){
      activity.finish();
      activity=null;
    }
  }
  /**
   * 结束指定的Activity
   */
  public void finishActivity(Activity activity){
    if(activity!=null){
      activityStack.remove(activity);
      activity.finish();
      activity=null;
    }
  }
  /**
   * 结束指定类名的Activity
   */
  public void finishActivity(Class<?> cls){
    for (Activity activity : activityStack) {
      if(activity.getClass().equals(cls) ){
        finishActivity(activity);
      }
    }
  }
  /**
   * 结束所有Activity
   */
  public void finishAllActivity(){
    for (int i = 0, size = activityStack.size(); i < size; i++){
      if (null != activityStack.get(i)){
        activityStack.get(i).finish();
      }
    }
    activityStack.clear();
  }
  /**
   * 退出应用程序
   */
  public void AppExit(Context context) {
    try {
      finishAllActivity();
      ActivityManager activityMgr= (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
      activityMgr.restartPackage(context.getPackageName());
      System.exit(0);
    } catch (Exception e) { 
      e.printStackTrace();
    }
  }
}

/**
 * Activity基类
 * @author Donkor
 */
public abstract class BaseActivity extends AppCompatActivity {

  @Override
  protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    //将Activity实例添加到AppManager的堆栈
    AppManager.getAppManager().addActivity(this);
  }


  @Override
  protected void onDestroy() {
    super.onDestroy();
    //将Activity实例从AppManager的堆栈中移除
    AppManager.getAppManager().finishActivity(this);
  }

}