AlertDialogがOnClickListenerの内側に表示されない

Question

をOnClickListenerの内部に表示したいとします。しかし、onclickListenerの中で次のコードを使用するとalertDialogが表示されません。 助けがあれば助かります。

final AlertDialog alertDialog = new AlertDialog.Builder(MyClass.this).create(); 
alertDialog.setTitle("Info:"); 
String alert1 = "First Name: " + Fname; 
String alert2 = "Surname: " + Sname; 
String alert3 = "Id: " + tId; 
String alert4 = "Password: " + tPassword; 
alertDialog.setMessage(alert1 +"\n"+ alert2 +"\n"+ alert3+"\n" + alert4); 
alertDialog.setButton("OK", new DialogInterface.OnClickListener() { 
        public void onClick(DialogInterface dialog, int which) { 

               startActivity(intent); 
              } 
             }); 

             alertDialog.show(); 
            }}); 

Answer 1

がonclicklistner内の以下のコードを追加し動作します：

AlertDialog.Builder dialog1 = new AlertDialog.Builder(this); 
      dialog1.setTitle("Info:"); 
      String alert1 = "First Name: " + Fname; 
      String alert2 = "Surname: " + Sname; 
      String alert3 = "Id: " + tId; 
      String alert4 = "Password: " + tPassword; 
      dialog1.setMessage(alert1 + "\n" + alert2 + "\n" + alert3 + "\n" + alert4); 
      dialog1.setButton("OK", new DialogInterface.OnClickListener() { 
       public void onClick(DialogInterface dialog, int which) { 

        startActivity(intent); 
       } 
      }); 
      dialog1.show(); 

Answer 2

使用これは

AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this); 
       builder.setTitle("ALERTTILESTRING") 
       .setMessage("alertNameString") 
       .setCancelable(false) 
       .setPositiveButton("OK",new DialogInterface.OnClickListener() { 
        public void onClick(DialogInterface dialog, int id) { 
         dialog.cancel(); 
        } 
       }); 
       AlertDialog alert = builder.create(); 
       alert.show(); 

Answer 3

AlertDialog.Builder builder = new AlertDialog.Builder(getActivity(), R.style.AppCompatAlertDialogStyle); 
      builder.setTitle(""); 
      builder.setMessage(""); 
      builder.setPositiveButton("ok", new DialogInterface.OnClickListener() { 
       public void onClick(DialogInterface dialog, int id) { 
        //do stuff 

       } 
      }); 
      builder.setNegativeButton("CLOSE", new DialogInterface.OnClickListener(){ 
       public void onClick(DialogInterface dialog, int id){ 
         //do stuff 
       } 
      }); 
      builder.show();