Develop Reference

How to add a custom view dynamically to a view in Visual Studio for Mac C#

I'm working through a project where I'm going to have multiple square size instances of the same set of form components.
I can either create 8 instances manually in my form UI or what I'd rather do is create a view (or Item Renderer) and then dynamically add instances of that view to my main view.
How do I add a create and add a custom view dynamically to the main view in my Xamarin form?
Note: Including Swift tag because you might know the answer if you know Swift or Objective C since the API wraps Apple API.
If IIUC:
Create a view in XCode Interface Builder
In ViewDidLoad create an instance of the custom instance views
Add each instance to the main view
I'd read a guide if there was one but I can't find anything specifically on this.
Some what related. I can create a new View in Xcode interface Builder pretty easily. Is there a way to export that as a class to my application?
Update:
I've found a textfield in Interface Builder where I can enter the name of a class. Back in Visual Studio my main View Controller can see the HelloWorld class. I've found a method named AddChildViewController. I try testing it. Nothing happens. Do I need to set the position and size? I can't find any API to do this.
Tomorrow I will scour the ancient texts again for example code. Maybe there is something I missed?
public override void ViewDidLoad()
{
base.ViewDidLoad();
var view = new HelloView(this.Handle);
var handle = view.Handle;
base.AddChildViewController(view);
var view2 = new HelloView(this.Handle);
handle = view.Handle;
base.AddChildViewController(view2);
}
I noticed a note in the console log:
<ViewController: 0x600000a94180> already have child of:
<ViewController: 0x600000a94180>
Update II:
This adds a new NSView and then a NSButton in that view to the main window:
var frame = new CoreGraphics.CGRect(0, 0, 100, 100);
var button = new NSButton(frame) {
Title = "My Button",
};
var view = new NSView(frame) {};
view.AddSubview(button);
View.AddSubview(view);
It doesn't add my custom class yet though.
Update III:
I'm able to add the custom HelloWorldView class but the controls are not visible. If I add a button to the form I see it but it is anchored to the bottom of the screen. I don't see the controls created from Interface Builder.
//var frame = this.View.Frame;
var frame = new CoreGraphics.CGRect(0, 0, 100, 20);
var button = new NSButton(frame) {
Title = "My Button"
};
var frame2 = new CoreGraphics.CGRect(0, 0, 100, 100);
var helloView = new HelloView() {
};
helloView.Frame = frame2;
helloView.AddSubview(button);
mainFrame.AddSubview(helloView);
HelloView.cs:
public partial class HelloView : NSView
{
public HelloView () : base ()
{
}
}
Note about the code above: I removed the handle parameter because it was causing a compiler error.
Setup: Visual Studio for Mac using Xamarin C# and XCode Interface Builder
--
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How do I navigate to another page from another c# class

I have a main page which has a play, options and exit button, both the play and exit button work as I followed a tutorial on it however for the options button I do not know how to navigate it. What I am planning to do is to create another class called optionsMenu.cs and have like a credits screen or a how to play guide on it.
These are the codes that I have for my options button.
var optionsGameButton = new Button(buttonTexture, buttonFont)
{
Position = new Vector2(300, 250),
Text = "Options",
};
optionsGameButton.Click += OptionsGameButton_Click;
_components = new List<Component>()
{
titleGameButton,
playGameButton,
optionsGameButton,
exitGameButton,
};
Finally I know I have to write a code in this area to be able to get the options button working but I don't know which kind of code to put.
private void OptionsGameButton_Click(object sender, EventArgs e)
{
Console.WriteLine("Credits");
}

If you're set on using click events, then you'll need to create a new instance of your options page and set it as the content of your control object within OptionsGameButton_Click. On the options page you'll need to set the xmlns to your optionsMenu.cs file.
I think you could also set the content of your control object by passing it as a parameter within the method itself, but I've only done this using the ICommand interface.

How to detect Xamarin Forms tabbed page click - iOS?

My scenario is, I have a Tabbed page in Xamarin Forms:
public partial class MainPage : TabbedPage
{
public MainPage()
{
InitializeComponent();
var playPage = new NavigationPage(new PlayPage())
{
Title = "Play",
Icon = "play.png"
};
var settingsPage = new NavigationPage(new SettingsPage())
{
Title = "Settings",
Icon = "settings.png"
};
var favoritesPage = new NavigationPage(new FavoritesPage())
{
Title = "Favorites",
Icon = "fave.png"
};
var aboutPage = new NavigationPage(new AboutPage())
{
Title = "About",
Icon = "info.png"
};
Children.Add(playPage);
Children.Add(favoritesPage);
Children.Add(settingsPage);
Children.Add(aboutPage);
}
}
I want to add a pause and play function to my app. On start up, the PlayPage would initially have the play.png icon and when I click on the PlayPage again it would change the icon to pause.png. Page is not changing just the page icon. Anyone has any idea how this could be done?
Edit:
So I have created a custom renderer, in OnElementChanged I utilize the ViewControllerSelected:
var tabbarController = (UITabBarController)this.ViewController;
if (null != tabbarController)
{
tabbarController.ViewControllerSelected += OnTabBarReselected;
}
And my OnTabBarReselected I have:
private void OnTabBarReselected(object sender, UITabBarSelectionEventArgs e)
{
switch (TabBar.SelectedItem.Title)
{
case "Play":
TabBar.SelectedItem.Title = "Pause";
TabBar.SelectedItem.Image = UIImage.FromFile("pause.png");
break;
}
}
This only does half of the work. It changes the Title of the selected tab bar from Play to Pause after I click on the same tab but not the Icon. The icon remains "play.png" until I get out of that tab page (selecting another tab). Anyone has any idea why?

You will need to implement a custom renderer to pull this off. There are some implementations on James Montemagno's blog where he talks about changing the icons.
iOS:
http://motzcod.es/post/138225183932/tintcolor-selectedimage-xamarin-forms-ios
Droid:
http://motzcod.es/post/157544468267/xamarin-forms-android-selected-and-unselected-tab-colors
This is however not necessarily related to your requirement of tapping the icon and changing that specific icon since all this code only runs when the page initially loads. It could be a nice starting point though. Check in there if there's a property on TabbedPage that changes when you tap on the current tab and change the icon at that point.
You also have a OnCurrentPageChanged event you can override in TabbedPage, but that isn't called when the page is already active.

Creating a windowless menu-bar icon application in Monomac/Xamarin C#

I am attempting to create an application in MonoMac/Xamarin.Mac that does not have a dock icon, nor a visible window when it launches and only an icon in the top-right menu bar.
I have set LSUIElement = 1 (tried both String and Boolean types) in Info.plist, but the status menu icon isn't displayed at all when the application launches. The only way I can get it to appear is by removing the LSUIElement flag, although then the dock icon becomes visible.
The snippet I am using is:
public partial class AppDelegate : NSApplicationDelegate
{
public AppDelegate ()
{
}
public override void FinishedLaunching (NSObject notification)
{
// Construct menu that will be displayed when tray icon is clicked
var notifyMenu = new NSMenu();
var exitMenuItem = new NSMenuItem("Quit",
(a,b) => { System.Environment.Exit(0); }); // Just add 'Quit' command
notifyMenu.AddItem(exitMenuItem);
// Display tray icon in upper-right-hand corner of the screen
var sItem = NSStatusBar.SystemStatusBar.CreateStatusItem(30);
sItem.Menu = notifyMenu;
sItem.Image = NSImage.FromStream(System.IO.File.OpenRead(
NSBundle.MainBundle.ResourcePath + #"/menu_connected.png"));
sItem.HighlightMode = true;
// Remove the system tray icon from upper-right hand corner of the screen
// (works without adjusting the LSUIElement setting in Info.plist)
NSApplication.SharedApplication.ActivationPolicy = NSApplicationActivationPolicy.Accessory;
}
}
Does anyone know of a good way of creating a windowless application in MonoMac that doesn't have a dock icon and only a menu bar icon?
Thanks,
BB

Try specifying a .xib for the "Main nib file name'
I did this some time ago, and it works fine for me. Something like this:
New monomac project
Created an 'AppController' class in C#:
[Register("AppController")]
public partial class AppController : NSObject
{
public AppController()
{
}
public override void AwakeFromNib()
{
var statusItem = NSStatusBar.SystemStatusBar.CreateStatusItem(30);
statusItem.Menu = statusMenu;
statusItem.Image = NSImage.ImageNamed("f3bfd_Untitled-thumb");
statusItem.HighlightMode = true;
}
In MainMenu.xib, I deleted the application menu
In MainMenu.xib, I added an custom object and set it's type to AppController
I created my status menu in the .xib and then connected it to the AppController with an outlet
In info.plist, I add the "Application is agent (UIElement)" value as a string and set it to "1"
Try it out with a .xib. If it doesn't work, maybe I can share my project for you to take apart.

Can't show NavigationBar on SplitView MonoTouch

I have a problem using an navigation bar on my split view. I want the navigationbar showing on the left view there my TableView is (see picture Click Here).
This is my AppDelegate:
public override bool FinishedLaunching (UIApplication app, NSDictionary options)
{
// create a new window instance based on the screen size
window = new UIWindow (UIScreen.MainScreen.Bounds);
this.masterViewController = new MasterViewControl();
this.detailViewController = new DetailViewController();
this.splitController = new UISplitViewController();
this.splitController.ViewControllers = new UIViewController[] {
this.masterViewController,
this.detailViewController
};
this.splitController.Delegate = new SplitControllerDelegate(this.detailViewController);
window.RootViewController = this.splitController;
// make the window visible
window.MakeKeyAndVisible ();
return true;
}
And the MasterViewController im trying to use it this way
'this.buttonAdd = new UIBarButtonItem("Edit", UIBarButtonItemStyle.Bordered, this.ButtonAdd_Clicked);
this.NavigationItem.SetRightBarButtonItem ( this.buttonAdd, true);'

You might want to try an existing solution, like MGSplitViewController. There's a video of it available here.
The original source code (objective-c) and MonoTouch bindings are available.
Or you can use a MonoTouch/C# port from Krumelur, which will be easier to use if you want to change/update the code base.