Question

菜单项未显示对话框下面是我的代码，当用户点击菜单项时，应该带他登录页面添加该代码。

public boolean onOptionsItemSelected(MenuItem item, int id) {
    switch (item.getItemId()) {
        case R.id.Login:
             startActivity(new Intent(this, Login.class));
             return true;
        case R.id.About:
         startActivity(new Intent(this, About.class));
            return true;
        case R.id.Post_Ads:
            AlertDialog.Builder builder = new AlertDialog.Builder(this);
            builder.setMessage("Are you sure you want to exit?")
                   .setCancelable(false);
            AlertDialog alert = builder.create();
                    alert.show();
                    startActivity(new Intent(this, Login.class));
             return true;


          }
    return super.onOptionsItemSelected(item);
}

Answer 1

试试这个，它应该有效：

public boolean onOptionsItemSelected(MenuItem item) {
            // TODO Auto-generated method stub
            switch (item.getItemId()) {
            case R.id.Login:
                Toast.makeText(getApplicationContext(), "Fired 1", Toast.LENGTH_SHORT).show();
                 startActivity(new Intent(this, Login.class));
                 return true;

            case R.id.About:
    Toast.makeText(getApplicationContext(), "Fired 2", Toast.LENGTH_SHORT).show();
             startActivity(new Intent(this, About.class));

                return true;
                        case R.id.Post_Ads:
                AlertDialog.Builder builder = new AlertDialog.Builder(this);
                builder.setMessage("Are you sure you want to exit?")
                       .setCancelable(false);
                AlertDialog alert = builder.create();
                        alert.show();
                        startActivity(new Intent(this, Login.class));

                 return true;


              }
        return super.onOptionsItemSelected(item);

        }

public boolean onOptionsItemSelected(MenuItem item, int id) Activity至class

中没有名为handle option menu's.的方法

处理此类事件的方法是onOptionsItemSelected(MenuItem)。

要显示的菜单项，您还必须使用以下方法，检查您是否也实现了此方法，

public boolean onCreateOptionsMenu(Menu menu) {
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.your_menu_file, menu);
    return true;
}

一个小小的修正，

您已实施以下Alertdialog方法

AlertDialog.Builder builder = new AlertDialog.Builder(this);
            builder.setMessage("Are you sure you want to exit?")
                   .setCancelable(false);
            AlertDialog alert = builder.create();
                    alert.show();
                    startActivity(new Intent(this, Login.class));

您在此处未提供任何确定或取消按钮，而且你也把它设置为可取消（假）。所以用户不能在这里选择任何选项。

所以我建议你在这里给出Ok和Cancel Button，并在onClick（）方法中做你想做的事情。如下例所示：

AlertDialog.Builder builder = new AlertDialog.Builder(this);
            builder.setMessage("Are you sure you want to exit?")
                   .setCancelable(false);
            AlertDialog alert = builder.create();
            alert.setButton("Ok", new DialogInterface.OnClickListener() {

                public void onClick(DialogInterface dialog, int which) {
                    // Do call some activity or close the app. Do what you wish to;

                }
            });

alert.setButton2("Cancel", new DialogInterface.OnClickListener() {

                public void onClick(DialogInterface dialog, int which) {
                    // Do stay in the current activity or something else. Do what you wish to;

                }
            });
                    alert.show();

             return true;

希望，这可能会有所帮助。

Answer 2

试试这个

AlertDialog.Builder builder = new AlertDialog.Builder(this);
            builder.setMessage("Navigate to login").setCancelable(false).setPositiveButton("OK", new DialogInterface.OnClickListener() {
                       public void onClick(DialogInterface dialog, int id) {
                            //do things
                           startActivity(new Intent(this, Login.class));
                       }
                   });

            AlertDialog alert = builder.create();
            alert.show();

即使没有错误，菜单项也不显示对话框

2 个答案: