private void setServerIp() {
    final EditText edittext = new EditText(this);
    edittext.setText(
        getSharedPreferences("aplicaint_info", 0).getString(ResourceData.SETTING_SERVERIP, ""));
    DialogUtil.showViewDialog(
        this,
        "设置服务器IP地址:",
        edittext,
        new DialogUtil.Handler() {
          @Override
          public void todo(DialogInterface dialog, int which) {
            if (!edittext.getText().toString().trim().equals("")) {
              if (checkString(edittext.getText().toString().trim())) {
                WriteSharedPreferences(
                    ResourceData.SETTING_SERVERIP, edittext.getText().toString());
                HttpUtil.BASE_URL = edittext.getText().toString();
                dolater();

              } else {
                DialogUtil.showAffirmDialog(
                    CampusdishclientActivity.this,
                    "错误",
                    "IP地址格式输入不正确!应为:192.168.1.1",
                    new DialogUtil.Handler() {
                      @Override
                      public void todo(DialogInterface dialog, int which) {
                        setServerIp();
                      }
                    },
                    new DialogUtil.Handler() {

                      @Override
                      public void todo(DialogInterface dialog, int which) {}
                    });
              }
            } else {
              DialogUtil.showAffirmDialog(
                  CampusdishclientActivity.this,
                  "错误",
                  "ip地址不能为空",
                  new DialogUtil.Handler() {
                    @Override
                    public void todo(DialogInterface dialog, int which) {
                      setServerIp();
                    }
                  },
                  new DialogUtil.Handler() {

                    @Override
                    public void todo(DialogInterface dialog, int which) {}
                  });
            }
          }
        },
        new DialogUtil.Handler() {

          @Override
          public void todo(DialogInterface dialog, int which) {}
        });
  }
 @Override
 public boolean dispatchKeyEvent(KeyEvent event) {
   if (event.getKeyCode() == KeyEvent.KEYCODE_BACK) {
     if (event.getAction() == KeyEvent.ACTION_UP && isBackKeyDown) {
       DialogUtil.showAffirmDialog(
           this,
           "确认",
           "确认退出?",
           true,
           new DialogUtil.Handler() {
             public void todo(DialogInterface dialog, int witch) {
               CampusdishclientActivity.this.finish();
               System.exit(0);
             }
           });
       isBackKeyDown = false;
       return true;
     } else if (event.getAction() == KeyEvent.ACTION_DOWN) {
       isBackKeyDown = true;
       return true;
     }
   }
   return super.dispatchKeyEvent(event);
 }