Question

我有一个带有自定义视图的DialogFragment，其中包含两个文本字段，用户可以在其中输入用户名和密码。单击肯定按钮时，我想验证用户在解除对话框之前确实输入了一些内容。

public class AuthenticationDialog extends DialogFragment {

    public Dialog onCreateDialog(Bundle savedInstanceState) {
        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
        LayoutInflater inflater = getActivity().getLayoutInflater();
        builder.setView(inflater.inflate(R.layout.authentication_dialog, null))
            .setPositiveButton(getResources().getString(R.string.login), new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int which) {
                    // TODO
                }
            })
            .setNegativeButton(getResources().getString(R.string.reset), new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int which) {
                    // TODO
                }
            });

        return builder.create();
    }
}

那么如何防止对话被解雇呢？我应该覆盖一些方法吗？

Answer 1

覆盖OnStart（）中的默认按钮处理程序来执行此操作。

@Override
public Dialog onCreateDialog(Bundle savedInstanceState)
{
    AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
    builder.setMessage("Test for preventing dialog close");
    builder.setPositiveButton("Test", 
        new DialogInterface.OnClickListener()
        {
            @Override
            public void onClick(DialogInterface dialog, int which)
            {
                //Do nothing here because we override this button later to change the close behaviour. 
                //However, we still need this because on older versions of Android unless we 
                //pass a handler the button doesn't get instantiated
            }
        });
    return builder.create();
}

@Override
public void onStart()
{
    super.onStart();    //super.onStart() is where dialog.show() is actually called on the underlying dialog, so we have to do it after this point
    AlertDialog d = (AlertDialog)getDialog();
    if(d != null)
    {
        Button positiveButton = (Button) d.getButton(Dialog.BUTTON_POSITIVE);
        positiveButton.setOnClickListener(new View.OnClickListener()
                {
                    @Override
                    public void onClick(View v)
                    {
                        Boolean wantToCloseDialog = false;
                        //Do stuff, possibly set wantToCloseDialog to true then...
                        if(wantToCloseDialog)
                            dismiss();
                        //else dialog stays open. Make sure you have an obvious way to close the dialog especially if you set cancellable to false.
                    }
                });
    }
}

有关其他对话框类型的更多说明和示例，请参阅我的答案https://stackoverflow.com/a/15619098/579234。

Answer 2

感谢Luksprog，我找到了解决方案。

<强> AuthenticationDialog.java ：

public class AuthenticationDialog extends DialogFragment implements OnClickListener {

    public interface AuthenticationDialogListener {
        void onAuthenticationLoginClicked(String username, String password);
        void onAuthenticationResetClicked(String username);
    }

    private AuthenticationDialogListener mListener;

    private EditText mUsername;
    private EditText mPassword;
    private Button mReset;
    private Button mLogin;

    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.authentication_dialog, container);
        this.getDialog().setTitle(R.string.login_title);

        mUsername = (EditText) view.findViewById(R.id.username_field);
        mPassword = (EditText) view.findViewById(R.id.password_field);
        mReset = (Button) view.findViewById(R.id.reset_button);
        mLogin = (Button) view.findViewById(R.id.login_button);

        mReset.setOnClickListener(this);
        mLogin.setOnClickListener(this);

        return view;
    }

    public void onAttach(Activity activity) {
        super.onAttach(activity);
        // Verify that the host activity implements the callback interface
        try {
            // Instantiate the NoticeDialogListener so we can send events to the host
            mListener = (AuthenticationDialogListener) activity;
        } catch (ClassCastException e) {
            // The activity doesn't implement the interface, throw exception
            throw new ClassCastException(activity.toString()
                    + " must implement AuthenticationDialogListener");
        }
    }

    public void onClick(View v) {
        if (v.equals(mLogin)) {
            if (mUsername.getText().toString().length() < 1 || !mUsername.getText().toString().contains("@")) {
                Toast.makeText(getActivity(), R.string.invalid_email, Toast.LENGTH_SHORT).show();
                return;
            } else if (mPassword.getText().toString().length() < 1) {
                Toast.makeText(getActivity(), R.string.invalid_password, Toast.LENGTH_SHORT).show();
                return;
            } else {
                mListener.onAuthenticationLoginClicked(mUsername.getText().toString(), mPassword.getText().toString());
                this.dismiss();
            }
        } else if (v.equals(mReset)) {
            mListener.onAuthenticationResetClicked(mUsername.getText().toString());
        }
    }
}

<强> authentication_dialog.xml ：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="vertical" >
    <EditText
        android:id="@+id/username_field"
        android:inputType="textEmailAddress"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:layout_marginLeft="4dp"
        android:layout_marginRight="4dp"
        android:layout_marginBottom="4dp"
        android:hint="@string/username"
        />
    <EditText
        android:id="@+id/password_field"
        android:inputType="textPassword"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="4dp"
        android:layout_marginLeft="4dp"
        android:layout_marginRight="4dp"
        android:layout_marginBottom="12dp"
        android:fontFamily="sans-serif"
        android:hint="@string/password"
        />
    <View
        android:layout_width="fill_parent"
        android:layout_height="1dip"
        android:background="?android:attr/dividerVertical" 
        />
    <LinearLayout 
        style="?android:attr/buttonBarStyle"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:paddingTop="0dp"
        android:measureWithLargestChild="true" >
        <Button 
            android:id="@+id/reset_button"
            style="?android:attr/buttonBarButtonStyle"
            android:layout_height="wrap_content"
            android:layout_width="0dp"
            android:layout_weight="1.0"
            android:text="@string/reset"
            />
        <Button 
            android:id="@+id/login_button"
            style="?android:attr/buttonBarButtonStyle"
            android:layout_height="wrap_content"
            android:layout_width="0dp"
            android:layout_weight="1.0"
            android:text="@string/login"
            />
    </LinearLayout>
</LinearLayout>

Answer 3

这是＆＃34;甜点＆＃34;解决了Karakuri和Sogger的答案。 Karakuri在正确的轨道上，但是如果已经显示，那么你只能获得按钮（否则，如评论中所述，它是空的）。这就是Sogger的答案有效的原因，但我更喜欢使用相同的方法设置onCreateDialog，而不是onStart。解决方案是将按钮的提取包装到对话框的OnShowListener中。

public Dialog onCreateDialog(Bundle savedInstanceState) {
  AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
  // your dialog setup, just leave the OnClick-listeners empty here and use the ones below

  final AlertDialog dialog = builder.create();
  dialog.setOnShowListener(new DialogInterface.OnShowListener() {
    @Override
    public void onShow(final DialogInterface dialog) {
      Button positiveButton = ((AlertDialog) dialog).getButton(DialogInterface.BUTTON_POSITIVE);
      positiveButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(final View v) {
          // TODO - call 'dismiss()' only if you need it
        }
      });
      Button negativeButton = ((AlertDialog) dialog).getButton(DialogInterface.BUTTON_NEGATIVE);
      // same for negative (and/or neutral) button if required
    }
  });

  return dialog;
}

Answer 4

您可以再次弹出对话框。或者，您可以禁用正按钮，直到两个字段都有输入。如果您在onCreateVew()中创建布局，这很容易。如果您正在使用AlertDialog.Builder类，则可以像这样获取按钮的句柄：

AlertDialog.Builder builder = new AlertDialog.Builder(context);
/* ... */
Dialog dialog = builder.create();
Button positiveButton = ((AlertDialog) dialog).getButton(DialogInterface.BUTTON_POSITIVE);
/* now you can affect the button */

防止DialogFragment在单击按钮时解除

4 个答案: