Unable to find suitable setter or adder for property Click of type Avalonia.Controls

[steskalja]

I am new to AvaloniaUI and I am trying to create a simple code-behind app, not mvvm. When I try to bind a button to Click as in the example documentation I cannot. I get the following error: Severity Code Description Project File Line Suppression State Error Unable to find suitable setter or adder for property Click of type Avalonia.Controls:Avalonia.Controls.Button for argument System.Private.CoreLib:System.String, available setter parameter lists are: System.EventHandler`1[[Avalonia.Interactivity.RoutedEventArgs, Avalonia.Interactivity, Version=0.9.0.0, Culture=neutral, PublicKeyToken=null]] (line 24 position 25) Line 24, position 25.

[steskalja]

Here is a screen shot showing the Click method is missing from the tag

[kekekeks]

You need your event handler to have exactly the required signature

public void OnButtonClick(object sender, RoutedEventArgs args)

[steskalja]

I've attempted that and it does not work. Attached is my sample code ArsAdd.zip

[obskyr]

I have a similar issue using Command in a MVVM app! This XAML:

      <Button Content="Add 1"
              Margin="0,10,0,0"
              HorizontalContentAlignment="Center"
              HorizontalAlignment="Stretch"
              Command="{Binding ButtonAddClicked}"/>

Gives me the error:

Unable to find suitable setter or adder for property Command of type Avalonia.Controls:Avalonia.Controls.Button for argument System.Private.CoreLib:System.String, available setter parameter lists are: Avalonia.UnsetValueType Avalonia.Data.IBinding System.Windows.Input.ICommand

However, it compiles fine. This error only shows up in Visual Studio's error list while editing, but doesn't actually obstruct compilation. Is there a way to avoid this?

[maxkatz6]

@obskyr you need to rebuild project, so xaml editor can see new changes in your assemblies.

[maxkatz6]

Original issue was answered. Sample code works with both 0.9.12 (issue is that old) and 0.10.12

[obskyr]

@maxkatz6 Thank you kindly!

[omarisai]

I am still seeing this issue in the last version, it would be better to adjust the documentation to a way that actually works.

[maxkatz6]

@omarisai what documentation page and what adjustments do you mean?

[omarisai]

Hi @maxkatz6; thanks for responding!

I was referring to Controls: Buttons documentation section Binding to Events, in the second code block.

I discovered my error 😅, my apologies, I was wrong, I was declaring the event in the ModelView file instead of the View file. After moving the event to the View file it worked.

[timunie]

@omarisai if you think there is something that can be done to improve the docs, feel free to send a PR for this.

[Mihawk2022]

found some problem in tutorial: https://docs.avaloniaui.net/docs/get-started/test-drive/respond-to-an-event

ButtonClicked function should be written in MainView.axaml.cs, not in MainWindow.axaml.cs

[timunie]

@Mihawk2022 that's not 100% true. If could be MainWindow or MainView, depending on the template used. But a PR to clarify this is welcome.

[gschlitt]

Following the tutorial https://docs.avaloniaui.net/docs/get-started/test-drive/respond-to-an-event definitely requires the placement of ButtonClicked eventhandler in MainView.axaml.cs

[zbarrier]

Ran into the button click issue today while following the tutorial. This really needs to be fixed, very frustrating.

[timunie]

@zbarrier a PR to the docs is really welcome 🤗

[zbarrier]

@zbarrier a PR to the docs is really welcome 🤗

I didn't have the time earlier when going through the tutorial. I will try to create PR with the change later. I really like Avalonia so far and understand it can be difficult to maintain the docs as they grow and things change.

[reelthymeos]

found some problem in tutorial: https://docs.avaloniaui.net/docs/get-started/test-drive/respond-to-an-event

ButtonClicked function should be written in MainView.axaml.cs, not in MainWindow.axaml.cs

This is still an issue in the documentation. Someone please update it.

[timunie]

@reelthymeos I don't see why it is wrong? You have to add the event handler to the control you are working on.

• Working on MainWindow? --> MainWindow.axaml.cs
• Working on MainView? --> MainView.axaml.cs
• Working on PersonView? --> PersonView.axaml.cs
• and so on

If you think this can be make more clear, feel free to file a PR proposal to the docs.

[cornerbowlsoftware]

I have defined a ContentControl that includes the exact code found in the documentation:

public void ClickHandler(object sender, RoutedEventArgs args)

The axaml includes the following inside the ControlTemplate definition:

<Button Click="ClickHandler">Press Me!</Button>

The application fails to compile with the above referenced error message.

[maxkatz6]

@cornerbowlsoftware

ControlTemplate

Control template is basically a static factory method, that won't have access to your instance-bound handler.

[cornerbowlsoftware]

Thanks, I figured that out a little later. I figured it out using someone else's post.

protected override void OnApplyTemplate(TemplateAppliedEventArgs e)
{
    var btn = e.NameScope.Find<Button>("PART_btn");
    if (btn != null)
    {
        btn.Click += ViewPswd;
    }
}

[maxkatz6]

@cornerbowlsoftware yeah, OnApplyTemplate is a preferred approach.

[sedwick2048]

In my OnApplyTemplate, btn was null. I had success with OnInit:

<UserControl ... Initialized="OnInit">

  private void OnInit(object sender, EventArgs e) {
    PART_btn.Click += ViewPswd;
  }

[reelthymeos]

Hi,

I am having this same issue. I have a button in my view:

<Button Grid.Row="1" Grid.Column="2" HorizontalAlignment="Left" Click="SendCommand_Click">Send</Button>

and in my view model:

public void SendCommand_Click(object sender, RoutedEventArgs args)
{
    //do some stuff
}

When I try to compile I get the above error. People on this thread are talking about use of some template to resolve this. Can someone explain what that is and how to use it? I am somewhat new to this and not familiar with templates and their usage.

[timunie]

Click is an event, not a command. It belongs into code behind not your viewmodel. You can also bind to commands which I prefer. Check Avalonia.Samples for a tutorial on that topic

[workgroupengineering]

Hi,

I am having this same issue. I have a button in my view:

<Button Grid.Row="1" Grid.Column="2" HorizontalAlignment="Left" Click="SendCommand_Click">Send</Button>

and in my view model:

public void SendCommand_Click(object sender, RoutedEventArgs args)
{
  //do some stuff
}

When I try to compile I get the above error. People on this thread are talking about use of some template to resolve this. Can someone explain what that is and how to use it? I am somewhat new to this and not familiar with templates and their usage.

Move this code in code-behind

public void SendCommand_Click(object sender, RoutedEventArgs args)
{
    //do some stuff
}

es: MyView.axaml.cs

If you need comunicate with VW using should use Command