How to disable / enable dialog negative positive b

2020-01-27 01:24发布

Please look at the custom dialog below. I have an edittext field on the dialog and if the text field is empty I would like to disable the positiveButton. I can get a charListener for the text field but I am not sure how I am going to set the positivebutton to disable or enable from that listener? What is the reference for the positive and negative buttons?

 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();
}

7条回答
The star\"
2楼-- · 2020-01-27 01:29

None of these answers really solve the problem.

I accomplish this using a custom layout with an EditText in it and a TextWatcher on that view.

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);
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叛逆
3楼-- · 2020-01-27 01:30
if(editTextEmailAddress.getText().toString().length()==0)
 {
 btnCancelCross.setEnabled(false);
}
else
{
 btnCancelCross.setEnabled(true);

}

That might help you thanks.

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Juvenile、少年°
4楼-- · 2020-01-27 01:35

This dialogFragment will do the job for you. Note that the dialog will remain open after screen rotation preserving any text that the user has already typed in. If you don't want that to happen you need to dismiss the fragment in your activity's onStop. The newInstance method signature can be changed to whatever you need.

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);
    }
}

Add implements to your activity (any type of Activity is fine):

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

Create the diaglogFragment in your activity like this:

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);

Handle the result in your activity like this:

@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.
}

You need to create the resource identifier so add this resource under somewhere under res/values

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <item name="dialog_edit_text" type="id"/>
</resources> 
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太酷不给撩
5楼-- · 2020-01-27 01:37

Here is complete code to enable and disable positive button of dialog:

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);

        }
    }
});
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乱世女痞
6楼-- · 2020-01-27 01:41

Edit for complete solution...

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);
        }

    }
});

Below are edited history, which can be refer as some more details

Here is a sample code, try this

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);
}

For negative button

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

For buttons id : Reference alert_dialog.xml

Edited :

And the setOnShowListener since level 8 API (FroYo), does the same,

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();

Edited

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();

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我只想做你的唯一
7楼-- · 2020-01-27 01:46

You can write a listener to the edit text box, and try to enable or disable buttons. This is a sample code for 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;
  }
};
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