在我的应用程序的某些状态下,我想在设置菜单中禁用某些CheckBoxPreferences。但是,如果用户点击它们,我希望出现一个解释性的toast。如果我只对CheckBoxPreference执行setEnable(false);,我确实可以得到正确的外观和感觉。但是,我无法在单击时显示toast。另一方面,我试图手动使CheckBoxPreference看起来像已禁用,但失败了。
你可以仅禁用偏好设置的视图,而无需禁用该偏好设置。
public class DisabledAppearanceCheckboxPreference extends CheckBoxPreference {
protected boolean mEnabledAppearance = false;
public DisabledAppearanceCheckboxPreference(Context context,
AttributeSet attrs) {
super(context, attrs);
}
@Override
protected void onBindView(View view) {
super.onBindView(view);
boolean viewEnabled = isEnabled()&&mEnabledAppearance;
enableView(view, viewEnabled);
}
protected void enableView( View view, boolean enabled){
view.setEnabled(enabled);
if ( view instanceof ViewGroup){
ViewGroup grp = (ViewGroup)view;
for ( int index = 0; index < grp.getChildCount(); index++)
enableView(grp.getChildAt(index), enabled);
}
}
public void setEnabledAppearance( boolean enabled){
mEnabledAppearance = enabled;
notifyChanged();
}
@Override
protected void onClick() {
if ( mEnabledAppearance)
super.onClick();
else{
// show your toast here
}
}
}
即使您的偏好设置已禁用,您仍然可以接收OnTouchEvents:
public class MyPreferenceFragment extends PreferenceFragment {
...
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = super.onCreateView(inflater, container, savedInstanceState);
final ListView listView = (ListView) view.findViewById(android.R.id.list);
listView.setOnTouchListener(new OnTouchListener() {
@Override
public boolean onTouch(View view, MotionEvent event) {
int position = listView.pointToPosition((int) event.getX(), (int) event.getY());
ListAdapter adapter = listView.getAdapter();
Preference preference = (Preference) adapter.getItem(position);
if (!preference.isEnabled())
Toast.makeText(getActivity(), "Sorry, this setting is not available!", Toast.LENGTH_LONG).show();
return false;
}
});
return view;
}
...
}