CODEWITHSUNDEEP
javaandroid
usalalas
usalalas

Reputation: 73

Problems displaying Dialog in Android

Every time I try to run this simple app, I get this error:

Unable to add window -- token null is not valid; is your activity running?

But if I change this line:

vdlgDialogToShow = new Dialog(this);

and add it to onCreate instead, it works.

public class MainActivity extends AppCompatActivity {

private Button vbtnShowDialog;
private Dialog vdlgDialogToShow;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    vbtnShowDialog = findViewById(R.id.btnShowDialog);

    vbtnShowDialog.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            displayValidateEmailPopup();

        }
    });

}

public void displayValidateEmailPopup(){

    // Criando variável necessária para mostrar a Dialog
    vdlgDialogToShow = new Dialog(getApplicationContext());

    vdlgDialogToShow.getWindow().setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));

    // Construindo Dialog
    vdlgDialogToShow.setContentView(R.layout.dialog);
    ImageView ivCloseWarningPopup = vdlgDialogToShow.findViewById(R.id.ivWarningDialogCloseImage);
    TextView vtvDialogTitleText = vdlgDialogToShow.findViewById(R.id.tvWarningDialogTitle);
    TextView vtvDialogBodyText = vdlgDialogToShow.findViewById(R.id.tvWarningDialogBodyText);
    ImageView vivDialogImage = vdlgDialogToShow.findViewById(R.id.ivWarningDialogImage);
    Button vbtnEnviarEmailConfirmacao = vdlgDialogToShow.findViewById(R.id.btnWarningDialogButton);

    // Populando os campos da Dialog
    vtvDialogTitleText.setText(R.string.warning_dialog_email_nao_confirmado_title);
    vtvDialogBodyText.setText(R.string.warning_dialog_email_nao_confirmado_body);
    vivDialogImage.setImageResource(R.drawable.ic_mail_white_dialog_warning);
    vbtnEnviarEmailConfirmacao.setText(R.string.enviar_email_button_text);

    // Verificando se a imagem que representa o fechamento da Dialog foi clicada
    ivCloseWarningPopup.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            vdlgDialogToShow.dismiss();
        }
    });

    // Verificando se o Botão de enviar email de confirmação foi clicado
    vbtnEnviarEmailConfirmacao.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            // Verificando se o dispositivo está conectado à rede
        }
    });

    vdlgDialogToShow.getWindow().setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));

    // Exibindo Dialog
    vdlgDialogToShow.show();

}
}

I just would like to know why. This is probably a rookie question. But any help would be appreciated.

Upvotes: 1

Views: 34

Answers (2)

Saurav Kumar
Saurav Kumar

Reputation: 970

In my case, it works just by changing getApplicationContext() to this. The reason for that getApplicationContext() is used to refer to the entire application which is used for application level. A dialog is part of an activity and hence, you cannot use application level context to initialize dialog.

Happy coding

Upvotes: 1

ismail alaoui
ismail alaoui

Reputation: 6073

It happened because you are showing your popup too early before activity is created and the parameter this is refereed to the context of the activity which is null before the creation of activity !

To avoid BadTokenException, you need to defer showing the popup until onCreate()methods is called which means activity window is displayed .

and that's why it works fine when you put the code in onCreate

Upvotes: 0

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