I want to navigate using RegionManager
regionManager.RequestNavigate("TabsView_region", "TabsView");
But it seems I've done something wrong, and nothing happens.
I'm sure that I registred TabsView for navigation. I've checked several times names of parameters. ViewModel of TabsView is connected with View through AutoWire. ViewModel implemets INavigationAware. I even created an empty project, where I simulated the same situation and in this case RequestNavigate works fine.
The question is if there is a way to get information, why navigation doesn't work?
Are you looking for
regionManager.RequestNavigate("TabsView_region", "TabsView", result => { if (!result.Result) MessageBox.Show(result.Exception.ToString()); } );
?
Related
Given something like this:
View = Backbone.Marionette.ItemView.extend({ });
myView = new View();
//region already exists
myLayout.region.show(myView)
//some time later this gets called again:
myLayout.region.show(myView)
I can see currentView in the docs but this only seems to apply at initialisation. Once a view is shown can I query the region to see the view? Either the view instance or type would be helpful. Looking in Chrome's debugger I can't see any properties/methods on the region that would help.
The motive for wanting to do this is so I don't show a static item view in a region again if it is already displayed as this can (especially if images are involved) cause a slight flickering effect on the screen.
Thanks
--Justin Wyllie
you can add a condition before calling show method:
if (myLayout.region.currentView != myView)
myLayout.region.show(myView)
so if you'll try to call show with the same View it wont be shown.
if you want to call region.show(myView) once you can check in this way:
if (_.isUndefined(myLayout.region.currentView))
myLayout.region.show(myView)
You can check the isClosed and $el attributes of the view. Something like
if (myView.isClosed || _.isUndefined(myView.$el)) {
myLayout.region.show(myView);
}
This is the same way the region checks to see if the view is closed or not:
show: function(view) {
this.ensureEl();
var isViewClosed = view.isClosed || _.isUndefined(view.$el);
...
I'm going out on a limb here and assuming that the OP's question is based on app behavior when navigating to different parts of the app via an anchor tag in the navigation or something similar.
This is how I found the question and I thought briefly that the answers would save my day. Although both answers so far are correct they do not quite solve the problem I was having. I wanted to display a persistent navigation bar. However, I did not want it to display on the login page. I was hopeful that detecting if a Region was already shown or not I'd be able to properly let the display logic take care of this.
As it turns out we were both on the right track to implement Regions as this provides granular control, but even after implementing the above I found that my nav bar would still "flicker" and essentially completely reload itself.
The answer is actually a bit ridiculous. Somehow in all the Backbone tutorials and research I've been doing the last two weeks I never came across the need to implement a javascript interface to interrupt normal link behavior. Whenever a navigation item was clicked the entire app was reloading. The routing was functioning so the content was correct, but the flicker was maddening.
I added the following to my app.js file right after the Backbone.history.start({pushState: true}); code:
// Holy crap this is SOOO important!
$(document).on("click", "a[href^='/']", function(event) {
if (!event.altKey && !event.ctrlKey && !event.metaKey && !event.shiftKey) {
event.preventDefault();
var url = $(event.currentTarget).attr("href").replace(/^\//, "");
Backbone.history.navigate(url, { trigger: true });
}
});
Check out this article for some explanation about the keyPress detection stuff. http://dev.tenfarms.com/posts/proper-link-handling
Boom! After adding this stuff in my app no longer completely reloads!
Disclaimer: I am very new to Backbone and the fact that the above was such a revelation for me makes me think that I may be doing something wrong elsewhere and this behavior should already exist in Backbone. If I've made a giant error here please comment and help me correct it.
I am having a lot of trouble with this and I have finally decided to come here. I feel as if I am making a noob mistake. I created a Passbook pass and I am using PKAddPassesViewController to add the pass. When I present the pass controller, the pass shows up correctly. However, when I decide to press "add" nothing happens, nothing gets logged or anything. After investigating, I added a delegate and the delegate method is as follows:
-(void)addPassesViewControllerDidFinish:(PKAddPassesViewController *)controller
{
[self dismissViewControllerAnimated:YES completion:nil];
}
However, instead for the normal animated dismiss, The controller dismisses as of the app crashes but instead goes to the previous view controller. This is absolutely driving me nuts and any help at all would be greatly appreciated :)
Thanks.
The addPassesViewControllerDidFinish is an optional delegate method, and it is called after the PKAddPassesViewController view controller has been dismissed. In your case, your code could be crashing because you are attempting to dismiss the parent view controller (self).
When 'nothing happens' when adding a pass, it is usually because the pass is not valid. The pass signature does not get checked until after the 'Add' button has been pressed, so this may explain why you see a pass displayed, but then it disappears after you press add. If everything works as expected if you press cancel, then this is probably your issue.
To get more info on what is happening to the Pass, turn on 'Additional Logging' in the Developer Settings on your device, then check the console log of the device (from the Organizer) as you try to add the pass to see if it gives any clues as to why the add is failing.
I have a text field that is apparently successfully calling delegate methods as the following method fires when I tap on the test field, but no keyboard shows.
- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField
{
NSLog(#"should begin editing");
return YES;
}
Any ideas as to why?
A couple of details: This text field happens to be in a view controller in a storyboard. The first time I segue to this view the text field works fine. The subsequent times I segue to this view it does not work. I imagine this is a big clue to why I am getting the described behavior, but I have not been able to figure it out yet.
I fixed the issue by adding the code below to the prepareForSegue: method. Seems to work.
if (_textField.isFirstResponder) {
[_textTextField resignFirstResponder];
}
I'm using storyboarding and have a UITableView containing events, which when clicked load another view with more details. I also have an 'add' button on that list which goes to the same page but doesn't prepopulate the information and changes the banner button.
I do it by setting the detail item with the following method, and then in the configureView method I just check if the detail item exists.
- (void)setDetailItem:(id)newDetailItem {
if (self.detailItem != newDetailItem) {
_detailItem = newDetailItem;
[self configureView];
} }
This works ok, but I thought there might be a better way to distinguish between methods, eg by getting the segue identifier in this new view controller and using that. Is there an easy way to do this or do I need to pass this information through as part of the prepareForSegue method?
Using prepareForSegue: seems right. In general, it's a bad idea for methods to care about the conditions under which they're being called if it's not explicit in their parameters.
I have a main ViewModel and a UserLoginViewModel. From the User view model I need to show a prompt with Ok/Cancel options. I've done it as stated in this link http://www.deanchalk.me.uk/post/WPF-MVVM-e28093-Simple-e28098MessageBoxShowe28099-With-Action-Func.aspx . To avoid Invalid-cross thread exception i used a dispatcher. The code is something like this
mainDispatcher.BeginInvoke(new MessageBoxDelegate
(
(message, title) => { Popup(msg, ""); }
), messageArgs);
where mainDispatcher is the dispatcher of MainView and Popup is of type Func<string, string, MessageBoxResult>
And it works fine. The problem is that I cannot get the results from the BeginInvoke Method. Is there is any way to get the result from the BeginInvoke method?
If is there is not, any suggestions how i can implement this?
I am not sure how it fits into the MVVM model, but I would suggest you to use the code4fun's MessagePrompt instead of a MessageBox
Obviously you get the result with a var result = Popup(msg, "");
You need to evaluate the result within BeginInvoke() because any code below BeginInvoke() runs before BeginInvoke().