I'm new to Xamarin.Forms and try to use Caliburn Micro like i did with WPF.
But my button click doesn't fire ?
My mainview does show on my connected phone, so far so good!
I know this is very basic but i can't get it work
<Button x:Name="Connect" Grid.Row="1" Text="Connect" TextColor="Gainsboro" BackgroundColor="green" />
In my view model :
public void Connect()
{
IntroLabel = "Caliburn.Micro!";
}
Kind Regards
Johan
Related
I am stuck with this annoying problem in iOS(works perfectly fine in Android) and I can't seem to find a solution at all. Could someone please help me? Thanks.
I have tabbed pages in which I have a Message Tab which consists of a collection view which shows the user messages. When the app starts I download about 5 messages and then wait for the remainingitemthresholdreached to fire so I can go ahead and fetch more data but unfortunately, it doesn't fire and I am stuck with the initial 5 messages.
XAML
<CollectionView Grid.Row="1" ItemsSource="{Binding AllMessages, Mode=TwoWay}" x:Name="myMessagesCV" SelectionMode="Single" SelectionChanged="MyMessagesCV_SelectionChanged" RemainingItemsThresholdReached="MyMessagesCV_RemainingItemsThresholdReached" RemainingItemsThreshold="5">
<CollectionView.ItemTemplate>
<DataTemplate>
// Some Code here
</DataTemplate>
</CollectionView.ItemTemplate>
</CollectionView>
Code Behind
private void MyMessagesCV_RemainingItemsThresholdReached(object sender, EventArgs e)
{
if (IsBusy)
return;
IsBusy = true;
if (!LoadedAllMyMessages)
{
GetMyMessages();
}
if (LoadedAllMyMessages)
{
myMessagesCV.RemainingItemsThreshold = -1;
}
}
Please someone save me. Cheers guys!
The RemainingItemsThresholdReached could be triggered with enough items.
You could check it in IncrementalLoadingPage of Scrolling. Or you could use the RemainingItemsThresholdReachedCommand
Here is the example for yoru reference. https://github.com/xamarin/xamarin-forms-samples/tree/master/UserInterface/CollectionViewDemos
I'm learning Xamarin Forms. And specifically, if I want to share a complex link, but have the text be something simple how do you do that? What I have now is below.
await Share.RequestAsync(new ShareTextRequest
{
Uri = "thelink",
Title = "title", //ios doesn't use title
Text = "extra text"
});
That obviously just puts in the link and some text. But I want something more akin to an html hyperlink.
Well if you are asking how to put a hiperlink in Xamarin forms, you can do it like this, just create a class in the Portable project and then call it from your XAML page, but remember to read the Xamarin Essentials documentation cause you need to put this in you info.plist:
<key>LSApplicationQueriesSchemes</key>
<array>
<string>lyft</string>
<string>fb</string>
</array>
If you mean the Label with Hyperlinks , you can have a look at this doc here .
The text displayed by Label and Span instances can be turned into hyperlinks, sample code as follow :
<Label>
<Label.FormattedText>
<FormattedString>
<Span Text="Alternatively, click " />
<Span Text="here"
TextColor="Blue"
TextDecorations="Underline">
<Span.GestureRecognizers>
<TapGestureRecognizer Command="{Binding TapCommand}"
CommandParameter="https://learn.microsoft.com/xamarin/" />
</Span.GestureRecognizers>
</Span>
<Span Text=" to view Xamarin documentation." />
</FormattedString>
</Label.FormattedText>
</Label>
When the hyperlink is tapped, the TapGestureRecognizer will respond by executing the ICommand defined by its Command property. In addition, the URL specified by the CommandParameter property will be passed to the ICommand as a parameter.
The code-behind for the XAML page contains the TapCommand implementation:
public partial class MainPage : ContentPage
{
// Launcher.OpenAsync is provided by Xamarin.Essentials.
public ICommand TapCommand => new Command<string>(async (url) => await Launcher.OpenAsync(url));
public MainPage()
{
InitializeComponent();
BindingContext = this;
}
}
The effect :
In addition , you also can create a reusable hyperlink class to make the xaml code more sample .
I've implemented Borderless Editor in my Xamarin.Forms application using Custom EditorRenderer. But I'm facing an issue that the editor text is not selectable at all in both cases, neither in Forms editor control nor in Rendered native editor control. My app has the functionality to let user copy paste the text in the editor while typing, like in any other text editing app. This is a basic feature in most of the apps and is by default there. But it's not working in my app. I've tried enabling it through
Control.SetTextIsSelectable(true);
but still it's not working. I've tried other things too, like:
Control.CustomSelectionActionModeCallback = new
CustomSelectionActionModeCallback();
Control.CustomInsertionActionModeCallback = new CustomInsertionActionModeCallback();
But nothing is working at all and text is not getting selected even a single word. Does anyone has any idea about this issue? How can I make the text selectable and allow default copy paste feature in custom editor?
Here's my code in Xaml:
<renderer:BorderlessEditor
Grid.Row="1"
x:Name="UserTextEditorAndroid"
BackgroundColor="{StaticResource WhiteColor}"
HeightRequest="350"
Margin="20,2"
MaxLength="1024"
IsReadOnly="{Binding Source={x:Reference LongTextTemplate}, Path=Editable, Converter={StaticResource InverseBool}}" />
And the custom render code is:
public class BorderlessEditorRenderer : EditorRenderer
{
public BorderlessEditorRenderer()
{
}
public static void Init() { }
protected override void OnElementChanged(ElementChangedEventArgs<Editor> e)
{
base.OnElementChanged(e);
if (e.OldElement == null)
{
Control.Background = null;
var layoutParams = new MarginLayoutParams(Control.LayoutParameters);
layoutParams.SetMargins(0, 0, 0, 0);
LayoutParameters = layoutParams;
Control.LayoutParameters = layoutParams;
Control.SetPadding(0, 0, 0, 0);
SetPadding(0, 0, 0, 0);
Control.SetTextIsSelectable(true);
Control.VerticalScrollBarEnabled = false;
}
}
}
Even if I use Xamarin.Forms own editor in Xaml instead of custom renderer then also it doesn't work at all. The text is still un-selectable.
I am having the same problem - but I'm not using Telerik. I'm running VS 2019 on Win 10. This is easy to repro ...
Create a new "Mobile App (Xamarin Forms)" and simply add an Editor to the MainPage.xaml file. I also put the Editor inside a ScrollView for kicks. The code below only shows a few words of text placed in the Editor, but I actually used a long paragraph from the Microsoft docs. I left that out below so as to simplify code presentation ... and avoid a mess!
<?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:d="http://xamarin.com/schemas/2014/forms/design"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
x:Class="Editor_Test.MainPage">
<StackLayout>
<!-- Place new controls here -->
<ScrollView>
<Editor Text="Visual Studio makes it easier ..."
HorizontalOptions="FillAndExpand"
VerticalOptions="FillAndExpand" />
</ScrollView>
</StackLayout>
</ContentPage>
I get normal behavior:
Because of the ScrollView, I can scroll the text with a finger (mouse) drag
A long press (click) selects the word pressed
A double tap (click) selects the word tapped
I get different results if I change 1 line of code in the App ctor, in App.xaml.cs, to instantiate the MainPage with a NavigationPage, like so:
public App()
{
InitializeComponent();
//MainPage = new MainPage();
MainPage = new NavigationPage(new MainPage());
}
Now the behavior changes:
A long press (click) has no effect (no selection)
A double tap (click) has no effect (no selection)
In fact there is no way at all that I can see to select text in the Editor. I don't know why this happens ... but it does. It drove me a bit mad until I realized what was causing it.
I'm using:
Xamarin Forms 4.5.0.495
Xamarin Essentials 1.3.1
Building for Android 9 (Pie)
I'm new to Android/Xamarin ... so my question is, how best to implement my own simple page navigation - ie, without using Xamarin's NavigationPage? I have a simple 3 page app I'd like to make some progress with!
I have a popup page in my application which includes some checkboxes, and I also have a ContentPage in my MainPage which contains some stacklayouts, I want to bind the IsVisible Property of my stacklayout to the IsChecked property of my checkbox (which is in another page), but i don't know how to do it, can anybody please help?
I've tried this, but it doesn't work
here's the code in my popup page:
<StackLayout Orientation="Horizontal" Spacing="60">
<local:Checkbox x:Name="va1Checkbox" Text="VA1"/>
<local:Checkbox x:Name="va2Checkbox" Text="VA2"/>
</StackLayout>
and this is the piece of code i have in my MainPage:
<StackLayout IsVisible="{Binding Source={x:Reference
va1Checkbox},Path=IsChecked}">
</StackLayout>
Thanks in advance
<StackLayout Orientation="Horizontal" Spacing="60">
<local:Checkbox x:Name="va1Checkbox" Text="VA1"/>
<local:Checkbox x:Name="va2Checkbox" Text="VA2"/>
</StackLayout>
I believe your popup represents some kind of settings based on which you control your StackLayout in Main Page.
If this is the case, there are two possible solutions.
Create a separate class which is binding for both checkbox and layout. You can use this either with MVVM or without it.
Value Passing: open popup from Main Page and register to its close event. When popup is closed you can use its checkbox's value to enable/disable the layout.
In your Popup.xaml.cs :
create an event action
public event Action<Popup> OnClose;
I believe you will have a way to close it. I don't know you are closing it so I will just use OnBackButtonPressed() here:
protected override bool OnBackButtonPressed()
{
OnClose?.Invoke(this);
return base.OnBackButtonPressed();
}
In your MainPage.xaml.cs :
private void OpenPopup()
{
var popup = new PopupPage();
popup.OnClose += OnPopupClosed;
}
void OnPopupClosed(Popup popup)
{
yourStackLayout.IsVisible = popup.va1Checkbox.Value;
}
UPDATE:
You can pass custom data class instead of popup object:
public class PopupData
{
public bool va1CheckboxValue;
public bool va1CheckboxValue;
// other data which you need to access in other page.
}
then
public event Action<PopupData> OnClose;
and
protected override bool OnBackButtonPressed()
{
PopupData data = new PopupData() { va1CheckboxValue = va1Checkbox.Value; }
OnClose?.Invoke(data);
return base.OnBackButtonPressed();
}
and in main page:
void OnPopupClosed(PopupData data)
{
yourStackLayout.IsVisible = data.va1CheckboxValue;
}
Hope this helps.
I don't know very well XAML and MVVM, but I think you can pass MainPage's ViewModel to Popup... if you change MainPage's ViewModel properties in Popup I think these changes will reflect also to MainPage's binded controls.
If you are not using MVVM (you should...), I think you have to pass a reference to properties used in MainPage to Popup... in this way, Popup can change MainPage's properties and its UI could change
I'm having a problem with showing Dialogs from a View Model. The problem is that the "underlying content is not dimmed and disabled" as the documentation says it should be. If I click on the underlying view the button in the dialog wired to the closed command is sometimes disabled and the user is not able to click it.
I defined the DialogHost in my MainView like this (also tried it in the ShellView):
<materialDesign:DialogHost
HorizontalAlignment="Center"
VerticalAlignment="Center"
CloseOnClickAway="True" />
From my MainViewModel I show the dialog like this:
Dim errView As New ErrorView
Dim res = Await DialogHost.Show(errView)
I wired up the close command on a button in the ErrorView dialog like this:
Command="{x:Static materialDesign:DialogHost.CloseDialogCommand}"
You problem is with the definition of DialogHost; you have it as an empty element.
The DialogHost is a ContentControl. Everything inside is what will become dimmed. So you define it at the root of your main Window/Page XAML, a bit more like:
<materialDesign:DialogHost CloseOnClickAway="True">
<StackPanel>
<TextBlock>Hello World</TextBlock>
<TextBlock>This is the main content of my application</TextBlock>
</StackPanel>
</materialDesign:DialogHost>