I want to implement a custom accordion ui element but the code has been written in C# ( https://github.com/Kimserey/AccordionView ) but I want to use xaml. I tried to add Accordion view in my content but while I am compiling I get following error
HomePage.xaml : error : The given key was not present in the dictionary.
Here is the my xaml code
<?xml version="1.0" encoding="UTF-8"?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:customaccordionmenu="clr-namespace:CustomAccordionMenu"
x:Class="CustomAccordionMenu.HomePage" Title="Accordion Example" >
<ContentPage.Content>
<StackLayout VerticalOptions = "Center">
<customaccordionmenu:AccordionView/>
</StackLayout>
</ContentPage.Content>
</ContentPage>
So I just want to create an accordionview and add the content in xaml, not in c#
PS: The project is for Xamarin.Forms
You are trying to instantiate an empty AccordionView. Judging by the code in github, the accordionview doesn't have a parameterless constructor, which could cause a problem.
Also the AccordionSectionView class calls
private ImageSource _arrowRight = ImageSource.FromFile("ic_keyboard_arrow_right_white_24dp.png");
as well as
private ImageSource _arrowDown = ImageSource.FromFile("ic_keyboard_arrow_down_white_24dp.png");
so if these files aren't in your app's resources and named in the very same way, this is also a possible cause for a crash.
Related
The "new" and recommended way to display a modal page with the Xamarin.Forms Shell uri-based navigation is to set this tag in the XAML file (source): Shell.PresentationMode="ModalAnimated"
and to navigate to it by using a standard route and invoking it with the function Shell.Current.GoToAsync("routeToMyPage").
However, this displays the modal page without a toolbar. Without Shell navigation, I would have wrapped this page in a NavigationPage, but since the pages are initialized through reflection (at least that's what it looks like - don't quote me on this), I don't know how to do that.
Adding a ToolbarItem in the page's XAML code doesn't solve this, neither does the Shell.NavBarIsVisible="True" property, and adding a Button in the Shell.TitleView tag doesn't display a toolbar either.
Is there a way to display the default navigation toolbar without rendering a custom one myself?
Here is the XAML code I used to try to have the Toolbar displayed:
<ContentPage
xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
Shell.PresentationMode="ModalAnimated"
Shell.NavBarIsVisible="True"
x:Class="StackOverflow.Views.MyModalPage">
<ContentPage.ToolbarItems >
<ToolbarItem Text="Hi"/>
</ContentPage.ToolbarItems>
<Shell.TitleView>
<Button Text="Toolbar Button"/>
</Shell.TitleView>
<ContentPage.Content>
</ContentPage.Content>
</ContentPage>
Edit: I have created a small sample project to showcase my issue: https://github.com/Kuurse/StackOverflowExample
You can first create the NavigationPage root page in the app class:
public partial class App : Application
{
public App()
{
InitializeComponent();
MainPage = new NavigationPage(new MainPage());
}
}
Then set like this in your mainpage.xaml:
<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
x:Class="StackOverflow.Views.MyModalPage"
NavigationPage.HasNavigationBar="True">
<ContentPage.ToolbarItems>
<ToolbarItem Text="Hi"/>
</ContentPage.ToolbarItems>
</ContentPage>
By the way, do you want to display only the default navigation toolbar?
I have a ContentPage which is assigned to the Xamarin.Forms.Shell class as a ShellContent and require the back button to be displayed in the navigation bar of the ContentPage.
The XAML source of the ContentPage in concern is as follows:
<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
x:Class="UI_test.TestPage">
<Shell.NavBarIsVisible>True</Shell.NavBarIsVisible>
<Shell.BackButtonBehavior>
<BackButtonBehavior IsEnabled="True" />
</Shell.BackButtonBehavior>
<Shell.FlyoutBehavior>Disabled</Shell.FlyoutBehavior>
<ContentPage.Content>
<StackLayout>
<Label Text="Welcome to Xamarin.Forms!"
VerticalOptions="CenterAndExpand"
HorizontalOptions="CenterAndExpand" />
</StackLayout>
</ContentPage.Content>
</ContentPage>
I found that that assigning a custom value to the attributes TextOverride and IconOverride of the <BackButtonBehavior> tag will display the back button, but I am looking for a way to display the platform's default back button (rather than a custom one) as the above ContentPage does not display as back button in its navigation bar as seen in the screenshot below.
Thanks in advance.
Your project seems to contain one page only, It won't appear if no navigation has been made, and it makes sense. If you do a Shell.GotoAsync(..) or Shell.Navigation.PushAsync(..) to navigate to another page it will then appears (the default native back button) allowing to go back to the previous page in the navigation stack.
Now I got started with Prism Framework for xamarine, but I'm having a little problem achieving connections across views.
I have this folder "Views" and inside it I have another folder called PartialViews. Now inside PartialViews I have a contentPage called "Header.xaml".
Now I would like to atach this file to the Index.xaml view, which is located in the Views folder. I would like to atach the "Header.xaml" to other views also, like for example I would like to atach it to the "Orders.xaml" view.
My Header.xaml file is as follows :
<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:prism="http://prismlibrary.com"
xmlns:local="clr-namespace:PROJECTX.Views"
prism:ViewModelLocator.AutowireViewModel="True"
x:Class="PROJECTX.Views.Header">
<StackLayout>
<Label Text="Trying partial views" />
</StackLayout>
</ContentPage>
While my Index.xaml is as follows:
<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:combobox="clr-namespace:Syncfusion.XForms.ComboBox;assembly=Syncfusion.SfComboBox.XForms"
xmlns:ListCollection="clr-namespace:System.Collections.Generic;assembly=mscorlib"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:prism="http://prismlibrary.com"
xmlns:local="clr-namespace:PROJECTX.Views"
prism:ViewModelLocator.AutowireViewModel="True"
x:Class="PROJECTX.Views.Index"
x:Name="selfi">
<ScrollView>
<local:Header mvvm:ViewModelLocator.AutowirePartialView="{x:Reference selfi}" />
<combobox:SfComboBox x:Name="comboBox">
<combobox:SfComboBox.ComboBoxSource>
<ListCollection:List x:TypeArguments="x:String">
<x:String>Rendit sipas: Me te kerkuara</x:String>
<x:String>Rendit sipas: Te fundit</x:String>
<x:String>Rendit sipas: Alfabetit</x:String>
</ListCollection:List>
</combobox:SfComboBox.ComboBoxSource>
</combobox:SfComboBox>
</ScrollView>
</ContentPage>
I also registred on my App.xaml.cs the routing of the PartialViews folder with the view model like this:
protected override void RegisterTypes(IContainerRegistry containerRegistry)
{
containerRegistry.RegisterForNavigation<NavigationPage>();
containerRegistry.RegisterForNavigation<MainPage, MainPageViewModel>();
containerRegistry.RegisterForNavigation<Index, IndexViewModel>();
//containerRegistry.RegisterForNavigation<Header, HeaderViewModel>();
ViewModelLocationProvider.Register<Header, HeaderViewModel>();
}
Now I get a few errors...
1. The property 'Content' is set more than once.
2. The attachable property 'AutowirePartialView' was not found in type 'ViewModelLocator'.
3. Property 'Content' does not support values of type 'Header'.
Now I know this might be a rookie question, but I just can't seem to get it to work this partial views thing.
Is my understanding of partial views in xamarin correct? I'm supposed to call the partial view from the view.. correct?
Any help I would really really appreciate.
So you have to understand that in Xamarin forms, you can only have one ContentPage object for a page, hence you are getting the error “Content is set more than once”. You can however have multiple Layouts inside a single page
Here’s a quick snippet explaining pages versus layouts
Since you’re looking to use the Prism "PartialViews", a common way of referencing them is a "Template". So you’d have a HeaderTemplate file as you have shared. But instead of a ContentPage object, you would use a ContentView object (which is of type Layout) and you would define the content of the header inside that. (Official Docs)
And then you can add it to any page using this line inside your XAML as you would add a regular layout:
<templates: HeaderTemplate/>
I'm new to xamarin forms, I created an Android Forms apps. But when i give x:Name="" to any element in xaml. In code behind i can't access this property id.
- I updated nuget packages even i keep trying to rebuild projects. But still unable to access xaml ids in code behind. I also uninstalled and installed visual studio multiple times. But still the same problem.
You have to build the project once after adding control in the Xaml.Then you will be able to access the control.
Try to execute this code and find what is wrong in your code:
TestPage.xaml:
<?xml version="1.0" encoding="UTF-8"?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
x:Class="TestImageCropping.TestPage">
<ContentPage.Content>
<Label x:Name="label1" Text="Hello"/>
<Button x:Name="button1" Text="Xamarin"/>
</ContentPage.Content>
</ContentPage>
TestPage.xaml.cs:
using System;
using System.Collections.Generic;
using Xamarin.Forms;
namespace TestImageCropping
{
public partial class TestPage : ContentPage
{
public TestPage()
{
InitializeComponent();
label1.TextColor = Color.Blue;
button1.Text = "Click here";
}
}
}
There are some issues related to x:Name property and accessing it in background...
Try to write it manually, it will work.
I am trying the Xamarin Forms for the first time so this may be a badly written question, pardon me please if so.
I have a image as a Embeded resource:
screenshot
Can i use that image as BackgroundImage in XAML, for the ContentPage? How
Thank you all in advance.
UPDATE, as proposed here:
https://developer.xamarin.com/guides/xamarin-forms/working-with/images/#Embedded_Images:
i added the custom xaml markup extension to main page cs:
[Xamarin.Forms.ContentProperty("Source")]
public class ImageResourceExtension : Xamarin.Forms.Xaml.IMarkupExtension
{
public string Source { get; set; }
public object ProvideValue(IServiceProvider serviceProvider)
{
if (Source == null)
{
return null;
}
// Do your translation lookup here, using whatever method you require
var imageSource = Xamarin.Forms.ImageSource.FromResource(Source);
return imageSource;
}
}
I can now use the image like this:
<StackLayout VerticalOptions="Center" HorizontalOptions="Center">
<!-- use a custom Markup Extension -->
<Image Source="{local:ImageResource App2.images.back_01.png}" />
</StackLayout>
Still the original question i am unable to answer, how to make it background in
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:local="clr-namespace:App2;assembly=App2"
x:Class="App2.MainPage"
BackgroundImage="">
It seems that making the image Embedded resource only in portable, works for all image usages except BackgroundImage.
To be used for BackgroundImage the image has to be also embedded in the per platform resources (correct per platform Build Action must be selected).
Then, for BackgroundImage, it can be refereed to like this: "folder_name/file_name.png"
So, it must be done several times instead once (as opposed to other image usages).
The above has worked for me as a solution.
If someone know how to do this without redundant actions, please do post.
Put images to folder:
for Android into Resources/drawable
for iOS into Resources
And then try
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:local="clr-namespace:App2;assembly=App2"
x:Class="App2.MainPage"
BackgroundImage="back01.png">