Android DialogFragment 完成按钮可点击

Question

我有一个带有编辑文本（自定义布局）的对话框片段。我想让“完成”按钮仅在编辑文本不为空时才可点击。当对话框打开时，它应该是不可点击的。

这是我的 DialogFragment 类：

public class AddNumberDialog extends DialogFragment {

private Context mContext;

@Override
public void onAttach(Activity activity) {
    super.onAttach(activity);
    mContext = activity;
}

@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
    LayoutInflater inflater = LayoutInflater.from(mContext);
    View mView = inflater.inflate(R.layout.dialog_add_number, null);

    final EditText mEditText = (EditText)
            mView.findViewById(R.id.number_edit_text);

    AlertDialog.Builder builder = new AlertDialog.Builder(mContext);
    builder.setView(mView)
            .setPositiveButton(R.string.dialog_done, new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int id) {
                    String number = mEditText.getText().toString();
                    //Add number to list
                }
            })
            .setNegativeButton(R.string.dialog_cancel, null);

    return builder.create();
}

}

Answer 1

你必须使用对话框。因为警报对话框按钮会在按下时关闭警报对话框。无需执行 OnClickListener 中的代码。 您可以阻止 AlertDialog 关闭。见this Answer if someone is interested。

重写 onStart 方法以设置Done Button Clickable False.

public class AddNumberDialog extends DialogFragment {

        private Context mContext;

        @Override
        public void onAttach(Activity activity) {
           super.onAttach(activity);
           mContext = activity;
        }


    Button button; // Your done Button


    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        LayoutInflater inflater = LayoutInflater.from(mContext);
        View mView = inflater.inflate(R.layout.dialog_add_number, null);

        final EditText mEditText = (EditText)
                mView.findViewById(R.id.number_edit_text);

        mEditText.addTextChangedListener(new TextWatcher(){
              public void afterTextChanged(Editable s) {
                    if(s.length()>0){
                          button.setEnabled(true);
                    }else{
                          button.setEnabled(false);
                    }
              }
              public void beforeTextChanged(CharSequence s, int start, int count, int after){}
              public void onTextChanged(CharSequence s, int start, int before, int count){}
        }); 


        AlertDialog.Builder builder = new AlertDialog.Builder(mContext);
        builder.setView(mView)
                .setPositiveButton(R.string.dialog_done, new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int id) {
                        // Do Nothing here... We Will be getting the Button Click Listener in Onstart
                    }
                })
                .setNegativeButton(R.string.dialog_cancel, null);

        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= (Button) d.getButton(Dialog.BUTTON_NEGATIVE);
            button.setOnClickListener(new View.OnClickListener()
                    {
                        @Override
                        public void onClick(View v)
                        {

                            String number = mEditText.getText().toString();
                            //Add number to list

                            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.
                        }
                    });
        }
    }
}