Come disabilitare / abilitare i pulsanti positivi negativi del dialogo?

Si prega di guardare la finestra di dialogo personalizzata di seguito. Ho un campo edittext nella finestra di dialogo e se il campo di testo è vuoto vorrei disabilitare il file positiveButton. Posso ottenere un charListener per il campo di testo ma non sono sicuro di come imposterò positivebuttonper disabilitare o abilitare da quel listener? Qual è il riferimento per i pulsanti positivo e negativo?

 case DIALOG_TEXT_ENTRY:
    // This example shows how to add a custom layout to an AlertDialog
    LayoutInflater factory = LayoutInflater.from(this);
    final View textEntryView = factory.inflate(R.layout.alert_dialog_text_entry, null);
    return new AlertDialog.Builder(AlertDialogSamples.this)
        .setIconAttribute(android.R.attr.alertDialogIcon)
        .setTitle(R.string.alert_dialog_text_entry)
        .setView(textEntryView)
        .setPositiveButton(R.string.alert_dialog_ok, new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int whichButton) {
                /* User clicked OK so do some stuff */
            }
        })
        .setNegativeButton(R.string.alert_dialog_cancel, new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int whichButton) {
                /* User clicked cancel so do some stuff */
            }
        })
        .create();
}

Modifica per una soluzione completa ...

AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
builder.setIcon(android.R.drawable.ic_dialog_info);
builder.setTitle("Alert dialog title");
builder.setMessage("This is the example code snippet to disable button if edittext attached to dialog is empty.");
builder.setPositiveButton("PositiveButton",
        new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface arg0, int arg1) {
                // DO TASK
            }
        });
builder.setNegativeButton("NegativeButton",
        new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface arg0, int arg1) {
                // DO TASK
            }
        });

// Set `EditText` to `dialog`. You can add `EditText` from `xml` too.
final EditText input = new EditText(MainActivity.this);

LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(
        LinearLayout.LayoutParams.MATCH_PARENT,
        LinearLayout.LayoutParams.MATCH_PARENT
);
input.setLayoutParams(lp);


builder.setView(input);

final AlertDialog dialog = builder.create();
dialog.show();

// Initially disable the button
((AlertDialog) dialog).getButton(AlertDialog.BUTTON_POSITIVE).setEnabled(false);

// OR you can use here setOnShowListener to disable button at first time.

// Now set the textchange listener for edittext
input.addTextChangedListener(new TextWatcher() {

    @Override
    public void onTextChanged(CharSequence s, int start, int before,
            int count) {
    }

    @Override
    public void beforeTextChanged(CharSequence s, int start, int count,
            int after) {
    }

    @Override
    public void afterTextChanged(Editable s) {

        // Check if edittext is empty
        if (TextUtils.isEmpty(s)) {
            // Disable ok button
            ((AlertDialog) dialog).getButton(AlertDialog.BUTTON_POSITIVE).setEnabled(false);

        } else {
            // Something into edit text. Enable the button.
            ((AlertDialog) dialog).getButton(AlertDialog.BUTTON_POSITIVE).setEnabled(true);
        }

    }
});

Di seguito è riportata la cronologia modificata, che può essere indicata come ulteriori dettagli

Ecco un codice di esempio, prova questo

AlertDialog.Builder builder = new AlertDialog.Builder(AddSchedule.this);
builder.setIcon(android.R.drawable.ic_dialog_info);
builder.setTitle("Alert dialog title");
builder.setMessage("Dialog message");
builder.setPositiveButton("Button1", new DialogInterface.OnClickListener() {
    public void onClick(DialogInterface arg0, int arg1) {
        //DO TASK
    }
});
builder.setNegativeButton("Button2", new DialogInterface.OnClickListener() {
    public void onClick(DialogInterface arg0, int arg1) {
        //DO TASK
    }
});

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

// After calling show method, you need to check your condition and enable/disable the dialog buttons 
if (your_condition_true) {
    // BUTTON1 is the positive button
    dialog.getButton(AlertDialog.BUTTON1).setEnabled(false);
}

Per bottone negativo

dialog.getButton(AlertDialog.BUTTON2).setEnabled(false); //BUTTON2 is negative button

Per i pulsanti id : riferimento alert_dialog.xml

Modificato :

E setOnShowListener dall'API di livello 8 (FroYo), fa lo stesso,

AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setPositiveButton(android.R.string.ok, null);

AlertDialog dialog = builder.create();
dialog.setOnShowListener(new OnShowListener() {

    @Override
    public void onShow(DialogInterface dialog) {
        if (condition) {
            ((AlertDialog)dialog).getButton(AlertDialog.BUTTON_POSITIVE).setEnabled(false);
        }
    }
});

dialog.show();

Modificato

new AlertDialog.Builder(this)
    .setMessage("This may take a while")
    .setPositiveButton("OK", new android.content.DialogInterface.OnClickListener() {

        @Override
        public void onClick(DialogInterface dialog, int which) {
            ((AlertDialog)dialog).getButton(which).setVisibility(View.INVISIBLE);
            // the rest of your stuff
        }

    }).show();

Nessuna di queste risposte risolve davvero il problema.

Realizzo questo utilizzando un layout personalizzato con un EditText in esso e un TextWatcher su quella vista.

final LinearLayout layout = (LinearLayout) inflator.inflate(R.layout.text_dialog, null);
final EditText text = (EditText) layout.findViewById(R.id.text_edit);
final AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setView(layout);
// Now add the buttons...
builder.setPositiveButton(R.string.ok, new AlertDialog.OnClickListener() {
    // Left out for brevity...
}
builder.setNegativeButton(R.string.cancel, new AlertDialog.OnClickListener() {
    // Left out for brevity...
}

// Create the dialog
final AlertDialog d = builder.create();

// Now add a TextWatcher that will handle enable/disable of save button
text.addTextChangedListener(new TextWatcher() {
    private void handleText() {
        // Grab the button
        final Button okButton = d.getButton(AlertDialog.BUTTON_POSITIVE);
        if(text.getText().length() == 0) {
            okButton.setEnabled(false);
        } else {
            okButton.setEnabled(true);
        }
    }
    @Override
    public void afterTextChanged(Editable arg0) {
        handleText();
    }
    @Override
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {
        // Nothing to do
    }
    @Override
    public void onTextChanged(CharSequence s, int start, int before, int count) {
       // Nothing to do
    }
});

// show the dialog
d.show();
// and disable the button to start with
d.getButton(AlertDialog.BUTTON_POSITIVE).setEnabled(false);

Ecco il codice completo per abilitare e disabilitare il pulsante positivo della finestra di dialogo:

AlertDialog.Builder builder = new AlertDialog.Builder(this);
LayoutInflater layoutInflater = MainActivity.this.getLayoutInflater();
View view = layoutInflater.inflate(R.layout.dialog,null);

builder.setView(view);
builder.setTitle("Test");
builder.setPositiveButton("ok", new DialogInterface.OnClickListener() {
    @Override
    public void onClick(DialogInterface dialog, int which) {
        Toast.makeText(MainActivity.this, "Ok clicked", Toast.LENGTH_SHORT).show();
        dialog.dismiss();
    }
});
builder.setNegativeButton("cancel", null);

final AlertDialog alertDialog = builder.create();

alertDialog.show();

EditText editText = (EditText)view.findViewById(R.id.mobile_number);
alertDialog.getButton(AlertDialog.BUTTON_POSITIVE).setEnabled(false);
editText.addTextChangedListener(new TextWatcher() {
    @Override
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {}

    @Override
    public void onTextChanged(CharSequence s, int start, int before, int count) {}

    @Override
    public void afterTextChanged(Editable s) {
        if (s.length() >= 1) {
            alertDialog.getButton(AlertDialog.BUTTON_POSITIVE).setEnabled(true);
        } else {
            alertDialog.getButton(AlertDialog.BUTTON_POSITIVE).setEnabled(false);

        }
    }
});

Puoi scrivere un listener nella casella di testo di modifica e provare ad abilitare o disabilitare i pulsanti. Questo è un codice di esempio per xamarin.

var dialog = builder.Create();

dialog.Show();

var btnOk = dialog.GetButton((int)DialogButtonType.Positive).Enabled = false;

_enterTextDialogEditText.AfterTextChanged += (sender, e) => {
  if (!string.IsNullOrEmpty(_enterTextDialogEditText.Text)) {
    dialog.GetButton((int)DialogButtonType.Positive).Enabled = true;
  } else {
    dialog.GetButton((int)DialogButtonType.Positive).Enabled = false;
  }
};

Per eliminare il record dalla visualizzazione dell'elenco del database utilizzando il titolare della visualizzazione, hai utilizzato questo codice nel tuo metodo getview ().

viewHolder.btn.setOnClickListener (new OnClickListener () {

                @Override
                public void onClick(View arg0) {
                    // TODO Auto-generated method stub
                    AlertDialog.Builder alertDialog2 = new AlertDialog.Builder(
                            Favorate.this.getParent());

                    // Setting Dialog Title
                    alertDialog2.setTitle("Confirm Delete...");

                    // Setting Dialog Message
                    alertDialog2
                            .setMessage("Are you sure you want delete ?");

                    // Setting Icon to Dialog
                    alertDialog2.setIcon(R.drawable.delete);

                    // Setting Positive "Yes" Btn
                    alertDialog2.setPositiveButton("YES",
                            new DialogInterface.OnClickListener() {
                                public void onClick(DialogInterface dialog,
                                        int which) {
                                    // Write your code here to execute after
                                    // dialog

                                    int id = _items.get(position).id;
                                    db.deleterecord(id);

                                    db.close();
                                }
                            });
                    // Setting Negative "NO" Btn
                    alertDialog2.setNegativeButton("NO",
                            new DialogInterface.OnClickListener() {
                                public void onClick(DialogInterface dialog,
                                        int which) {
                                    // Write your code here to execute after
                                    // dialog

                                    dialog.cancel();
                                }
                            });

                    // Showing Alert Dialog
                    alertDialog2.show();

                }
            });

Leggi di più

Questo dialogFragment farà il lavoro per te. Nota che la finestra di dialogo rimarrà aperta dopo la rotazione dello schermo, preservando il testo che l'utente ha già digitato. Se non vuoi che ciò accada, devi chiudere il frammento in onStop della tua attività. La firma del metodo newInstance può essere modificata in base alle esigenze.

import android.app.Activity;
import android.app.Dialog;
import android.app.DialogFragment;
import android.content.DialogInterface;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v7.app.AlertDialog;
import android.text.Editable;
import android.text.TextWatcher;
import android.widget.EditText;

public class TextViewDialogFragment extends DialogFragment implements DialogInterface.OnClickListener, DialogInterface.OnShowListener, TextWatcher
{
    final static private String TITLE = "title", MESSAGE = "message", IDENTIFIER = "identifier", INPUT_TYPE = "inputType", POSITIVE_TEXT = "pText", NEGATIVE_TEXT = "nText", CANCELABLE = "cancelable";

    public TextViewDialogFragment()
    {
        super();
    }

    static public TextViewDialogFragment newInstance(int title, @Nullable String message, int identifier, int inputType, int positiveText, int negativeText, boolean cancelable)
    {
        TextViewDialogFragment fragement = new TextViewDialogFragment();
        Bundle args = new Bundle();
        args.putInt(TITLE, title);
        args.putString(MESSAGE, message);
        args.putInt(IDENTIFIER, identifier);
        args.putInt(INPUT_TYPE, inputType);
        args.putInt(POSITIVE_TEXT, positiveText);
        args.putInt(NEGATIVE_TEXT, negativeText);
        args.putBoolean(CANCELABLE, cancelable);
        fragement.setArguments(args);
        return fragement;
    }

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState)
    {
        Activity activity =  getActivity();
        Bundle args = getArguments();
        EditText input = new EditText(activity);
        input.setInputType(args.getInt(INPUT_TYPE));
        input.setId(R.id.dialog_edit_text);
        input.addTextChangedListener(this);
        AlertDialog.Builder alert = new AlertDialog.Builder(activity);
        alert.setCancelable(args.getBoolean(CANCELABLE)).setTitle(args.getInt(TITLE)).setMessage(args.getString(MESSAGE)).setView(input).setPositiveButton(args.getInt(POSITIVE_TEXT), this);
        int negativeText = args.getInt(NEGATIVE_TEXT);
        if (negativeText != 0)
        {
            alert.setNegativeButton(negativeText, this);
        }
        AlertDialog dialog = alert.create();
        dialog.setOnShowListener(this);
        return dialog;
    }

    @Override
    public void onShow(DialogInterface dialog)
    {
        // After device rotation there may be some text present.
        if (((EditText)((AlertDialog) dialog).findViewById(R.id.dialog_edit_text)).length() == 0)
        {
            ((AlertDialog) dialog).getButton(AlertDialog.BUTTON_POSITIVE).setEnabled(false);
        }
    }

    @Override
    public void onClick(DialogInterface dialog, int which)
    {
        String text = ((EditText)((AlertDialog) dialog).findViewById(R.id.dialog_edit_text)).getText().toString();
        ((Callbacks) getActivity()).onTextViewDialogResult(which, getArguments().getInt(IDENTIFIER), text);
    }

    @Override
    public void onCancel(DialogInterface dialog)
    {
        ((Callbacks) getActivity()).onTextViewDialogActivityCancelled(getArguments().getInt(IDENTIFIER));
        super.onCancel(dialog);
    }

    @Override
    public void beforeTextChanged(CharSequence s, int start, int count, int after)
    {
    }

    @Override
    public void onTextChanged(CharSequence s, int start, int before, int count)
    {
    }

    @Override
    public void afterTextChanged(Editable s)
    {
        ((AlertDialog) getDialog()).getButton(AlertDialog.BUTTON_POSITIVE).setEnabled(s.length() > 0);
    }

    void setMessage(String message)
    {
        Bundle args = getArguments();
        args.putString(MESSAGE, message);
        setArguments(args);
    }

    interface Callbacks
    {
        void onTextViewDialogResult(int which, int identity, String text);
        void onTextViewDialogActivityCancelled(int identity);
    }
}

Aggiungi strumenti alla tua attività (qualsiasi tipo di attività va bene):

public class Myctivity extends AppCompatActivity implements TextViewDialogFragment.Callbacks
{
...
}

Crea il diaglogFragment nella tua attività in questo modo:

final static int SOMETHING = 1;
myDF = TextViewDialogFragment.newInstance(R.string.my_title, "my message", SOMETHING, InputType.TYPE_CLASS_TEXT | InputType.TYPE_TEXT_FLAG_CAP_WORDS | InputType.TYPE_TEXT_FLAG_CAP_SENTENCES, /* Whatever is best for your user. */    R.string.yay, android.R.string.cancel, true);

Gestisci il risultato della tua attività in questo modo:

@Override
public void onTextViewDialogResult(int which, int identity, String text)
{
    if (which == AlertDialog.BUTTON_NEGATIVE)
    {
        // User did not want to do anything.
        return;
    }
    // text now holds the users answer.
    // Identity can be used if you use the same fragment for more than one type of question.
}
@Override
public void onTextViewDialogActivityCancelled(int identity)
{
    // This is invoked if you set cancelable to true and the user pressed the back button.
}

Devi creare l'identificatore della risorsa, quindi aggiungi questa risorsa da qualche parte sotto res / values

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <item name="dialog_edit_text" type="id"/>
</resources> 

if (editTextEmailAddress.getText().toString().length() == 0) {
    btnCancelCross.setEnabled(false);
} else {
    btnCancelCross.setEnabled(true);
}

Questo potrebbe aiutarti grazie.