问题
I want to have an EditTextPreference that will disable the OK button if there is no text in the EditText field. I created a custom EditTextPreference class and I am able to get the EditText object and set a TextWatcher, but I can't find a way to disable the button. It looks like I just don't have access to the OK and Cancel buttons in the Dialog.
Anyone know a way to get at these buttons or to do what I am trying to do?
Only other option is to try to create from scratch a custom Dialog that looks like and mimics the EditTextPreference.
回答1:
Here is a code sample that enables/disables button depending on whether onCheckValue
function returns true
or false
.
public class ValidatedEditTextPreference extends EditTextPreference
{
public ValidatedEditTextPreference(Context ctx, AttributeSet attrs, int defStyle)
{
super(ctx, attrs, defStyle);
}
public ValidatedEditTextPreference(Context ctx, AttributeSet attrs)
{
super(ctx, attrs);
}
private class EditTextWatcher implements TextWatcher
{
@Override
public void onTextChanged(CharSequence s, int start, int before, int count){}
@Override
public void beforeTextChanged(CharSequence s, int start, int before, int count){}
@Override
public void afterTextChanged(Editable s)
{
onEditTextChanged();
}
}
EditTextWatcher m_watcher = new EditTextWatcher();
/**
* Return true in order to enable positive button or false to disable it.
*/
protected boolean onCheckValue(String value)
{
return Strings.hasValue(value);
}
protected void onEditTextChanged()
{
boolean enable = onCheckValue(getEditText().getText().toString());
Dialog dlg = getDialog();
if(dlg instanceof AlertDialog)
{
AlertDialog alertDlg = (AlertDialog)dlg;
Button btn = alertDlg.getButton(AlertDialog.BUTTON_POSITIVE);
btn.setEnabled(enable);
}
}
@Override
protected void showDialog(Bundle state)
{
super.showDialog(state);
getEditText().removeTextChangedListener(m_watcher);
getEditText().addTextChangedListener(m_watcher);
onEditTextChanged();
}
}
回答2:
need change the old EditTextPreference to the new ValidatedEditTextPreference in preference.xml.
I did the following:
Old code:
<EditTextPreference
android:dialogMessage="Please input your email"
android:dialogTitle="Set email"
android:key="Email"
android:summary="Your email"
android:title="-Missed call send to" android:defaultValue="xxx@xxx.xxx"/>
New code:
<com.tanggod.missedcall2mail.ValidatedEditTextPreference
android:dialogMessage="Please input your email"
android:dialogTitle="Set email"
android:key="Email"
android:summary="Your email"
android:title="-Missed call send to" android:defaultValue="xxx@xxx.xxx"/>
来源:https://stackoverflow.com/questions/4762027/edittextpreference-disable-buttons