i made custom view which extend textView with this constractors :
// Default constructor override
public AutoResizeTextView(Context context) {
this(context, null);
}
// Default constructor when inflating from XML file
public AutoResizeTextView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
how to i add it to my palette in android studio ?
i saw button that allows to to chose custom view but after i click on it nothing happen :
after i click on the class that i want the window is closed and nothing happen ...
I found this official guide to add custom views in the palette.
Related
We have designed a custom popup with Content View, which will be invoked in a content page. When clicked on hardware back custom popup is getting closed, because Content View as no property to hand hardware back button Pressed. OnBackButtonPressed() is used only for Content Page. Can I get any solution to handle hardware back for content view to stop popup from closing.
To manage hardware back button you must override OnBackPressed() method in MainActivity class, in android project. In your popup you may have some property to check if can be closed and then check it from MainActivity class.
public override void OnBackPressed()
{
if (CheckIfCanBePressedMethod())
{
// back pressed will be ignored
// code here
}
else
{
// default behavior
base.OnBackPressed();
}
}
Set the flag on Contentpage when you open popup make the bool as true.
bool isShowPopup = false;
public override void OnBackPressed()
{
if (!isShowPopup)
{
base.OnBackPressed();
}
}
We're using Xamarin.Forms with MacOS, and have a custom view MyCustomView : Xamarin.Forms.ContentView, and I'm trying to create a custom view renderer for our view, but it's interfering with the rendered view.
Does anyone know how to create a view renderer in my platform project?
This is the code I've tried so far, looking at similar places:
[assembly: Xamarin.Forms.ExportRenderer(typeof(MyCustomView), typeof(MyCustomViewRenderer))]
namespace Mac.Renderers
{
public class MyCustomViewRenderer : ViewRenderer<Xamarin.Forms.ContentView, AppKit.NSView>
{
public MyCustomViewRenderer()
{
// My implementation
}
}
}
Event when the implementation is left blank, having this custom renderer is affecting the display of the ContentView, so I think this code must not be right - is there a way to do this?
You could fix your issue by changing your class to inherit from VisualElementRenderer<T> instead.
[assembly: Xamarin.Forms.ExportRenderer(typeof(MyCustomView), typeof(MyCustomViewRenderer))]
namespace Mac.Renderers
{
public class MyCustomViewRenderer : VisualElementRenderer<ContentView>
{
public MyCustomViewRenderer()
{
// My implementation
}
}
}
Page has a default Renderer "PageRenderer", do not understand why ContentView does not. It would be nice if there was a ContentViewRenderer.
Hope this helps.-
In my Xamarin app, I create a button (Xamarin.Forms.Button) programmatically. I need this button to show a different background image under normal vs hovered state. I have created a style resource similar to what is described at How to indicate currently selected control in Xamarin?. However, I cannot figure out how to apply this style to the button.
The Button class exposes a property called Image that is of FileImageSource type. The closest API I found to load my style resource is ImageSource.FromResource static method. However, this method seems to return StreamImageSource instance which is not what we need.
Class Button does not seem to provide any Style property.
Can you please suggest how I can programmatically associate a style to the button? Regards.
To achieve this request you need custom renderers.
To be able to apply your style f.e.: "myButtonStyle.xml" you have to create a custom renderer for your target platform:
Android:
[assembly: ExportRenderer (typeof (YourExtendedButtonClass), typeof (MyCustomButtonRenderer))]
namespace YourApp.Droid
{
public class MyCustomButtonRenderer : ButtonRenderer
{
protected override void OnElementChanged(ElementChangedEventArgs<Button> e)
{
base.OnElementChanged(e);
var myButton = this.Control as Android.Widget.Button;
myButton?.SetBackgroundResource(Resource.Drawable.myButtonStyle);
}
}
}
I am new to Xamarin and MVVMCross. So I have created 2 views. Login and Register. I have a button on Login to goto Register view and I am going there by this code in the Login's ViewModel:
// method when user tap register button
public IMvxCommand NavigateRegister
{
get { return new MvxCommand(() => ShowViewModel<RegisterViewModel>()); }
}
It works ok the Register Page opens well. But once I assign Name for a single object on Register view (a textEdit), the app crash when I tap on the Register button.
Below is the error msg:
Xamarin.iOS: Received unhandled ObjectiveC exception:
NSUnknownKeyException [
setValue:forUndefinedKey:]: this class is not key value
coding-compliant for the key regNameEdit.
EDIT:
More details: I already assigned the name (see pic below), but still crash:
And the view also been assigned to its Class "CreateAccount". But I am noticing the class declaration has "partial" darkened out in the "public partial class CreateAccount : MvxViewController" line. That's the only noticeable difference btw this class and the first one.
using MvvmCross.Binding.BindingContext;
using MvvmCross.iOS.Views;
namespace MyApp.iOS.Views
{
public partial class CreateAccount : MvxViewController
{
public CreateAccount() : base("CreateAccount", null)
{
}
public override void ViewDidLoad()
{
base.ViewDidLoad();
// Perform any additional setup after loading the view, typically from a nib.
Title = "Register";
var set = this.CreateBindingSet<CreateAccount, Core.ViewModels.CreateAccountModel>();
set.Bind(regNameEdit).To(vm => vm.NameStr);
}
public override void DidReceiveMemoryWarning()
{
base.DidReceiveMemoryWarning();
// Release any cached data, images, etc that aren't in use.
}
}
}
The Bind(regNameEdit) also is an error (not detecting the textedit still)
This usually means that the a control is not defined in the View/ViewController class in your case the regNameEdit.
Make sure you created the back Property for this Edit and that the class assigned to the XIB is the one containing this property.
If you are using Xamarin Studio Designer you create the back property selecting the UIControl in the XIB/StoryBoard and setting a name, then enter.
This will create a property with the name you specified accessible in the ViewController.
public override void ViewDidLoad()
{
base.ViewDidLoad();
this.MyUITextField.Text = string.Empty;
}
UPDATE
When using Storyboard:
Try this: Remove the name from the TextField and also remove the name from the ViewController class, then clean your project and rebuild. Re-add the class to the ViewController but when doing it click over the yellow icon in the bottom, there put the name and hit enter. Continue with the TextField, select it put the name and hit enter.
UPDATE # 2
When using XIBs
When you create the ViewController from the menu, Xamarin Studio will create both the ViewController class and the XIB file and will associate one with the other so here you don't have to do anything else to link them.
For the TextField you will need to do it adding the name as previously indicated.
Try this: Remove the name of the UITextField and save and clean/rebuild the project then add the name and hit enter.
Something you can do to verify if there's any problem, double click on the button in the XIB and this should take you to the ViewController class to create a method.
Hope this helps.
I have recently updated xamarin forms to 1.5.1-pre1 so that I can use the beautiful AppCompat themes. It works and looks very nice.
I do have one problem, in my old FormsApplicationActivity I used to override the OnOptionsItemSelected method to intercept when the user was clicking on the back arrow icon and do some viewmodel cleanup. Apparently this method is not being called after using the FormsAppCompatActivity.
How can I intercept the "soft" back button press (toolbar icon not hard back button) ?
I also tried to override the Xamarin.Forms.Platform.Android.AppCompat.NavigationPageRenderer but i can't seem to override it :(
Does anyone have a clue how I can intercept this?
You can add the following to your custom renderer. You can either user current activity plugin or cast your context to activity.
var toolbar = CrossCurrentActivity.Current?.Activity?.FindViewById<Toolbar>(Resource.Id.toolbar);
toolbar.NavigationClick += ToolbarNavigationClick;
Have a look at the last two lines of the OnCreate() After adding them OnOptionsItemSelected was called as expected).
https://raw.githubusercontent.com/UdaraAlwis/Xamarin-Playground/master/XFNavBarBackBtnClickOverride/XFNavBarBackBtnClickOverride/XFNavBarBackBtnClickOverride.Droid/MainActivity.cs
Toolbar toolbar = this.FindViewById<Toolbar>(Resource.Id.toolbar);
SetSupportActionBar(toolbar);
In Xamarin.Forms there's a better way to intercept the NavigationBar back button pressed and the hardware back button pressed, which is creating your own NavigationRenderer and overriding the method OnPopViewAsync:
[assembly: ExportRenderer(typeof(NavigationPage), typeof(CustomNavigationRenderer))]
namespace YourApp.Droid
{
public class CustomNavigationRenderer : NavigationPageRenderer
{
public CustomNavigationRenderer(Context context) : base(context)
{
}
protected override async Task<bool> OnPopViewAsync(Page page, bool animated)
{
// Write your code here
}
}
}
Hope this helps