C#•2y ago

❔ Using mvvm toolkit- Why my view has no access to my command?

I got the following Code in the view model:

      [RelayCommand]
        public void CalculateAndSave()

      [RelayCommand]
        public void CalculateAndSave()

And the view:

And in the View:
<Window x:Class="Calculator.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:VM="clr-namespace:Calculator.ViewModels"
        xmlns:local="clr-namespace:Calculator"
        mc:Ignorable="d"
        Title="MainWindow" Height="525" Width="350">
    <Window.DataContext>
        <VM:CalculatorVM/>
    </Window.DataContext>

And in the View:
<Window x:Class="Calculator.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:VM="clr-namespace:Calculator.ViewModels"
        xmlns:local="clr-namespace:Calculator"
        mc:Ignorable="d"
        Title="MainWindow" Height="525" Width="350">
    <Window.DataContext>
        <VM:CalculatorVM/>
    </Window.DataContext>

I got a few button on the view, when it try to give the button a command to CalculateAndSave, method isn't available, is my binding wrong?

65 Replies

ACiDCA7•2y ago

is just the designer saying its not available or did you try it during running app to check if the method is called? if its just the designer.. well it isnt so smart.. you would have to tell it more explicitly of what type the datacontext is

antimatter8189OP•2y ago

Meaning what? i tried just now running it didnt hit the breakpoint of the command so it aint working for sure

ACiDCA7•2y ago

ok well since you didnt copy the part of the button i cant help further

antimatter8189OP•2y ago

        <Button x:Name="oneButton"
                Command="{Binding CalculateAndSave}"
                Click="NumberButton_Click"
                Style="{StaticResource numberButtonsStyle}"
                Content="1"
                Grid.Row="4"/>

        <Button x:Name="oneButton"
                Command="{Binding CalculateAndSave}"
                Click="NumberButton_Click"
                Style="{StaticResource numberButtonsStyle}"
                Content="1"
                Grid.Row="4"/>

@ACiDCA7 nothing to see much just want to bind a command to it

ACiDCA7•2y ago

click and command maybe clashing?

antimatter8189OP•2y ago

hmm Nop. now when i click nothing happens command isnt binded Probably the entire view model isnt binded properly no autocompletion on the method name

ACiDCA7•2y ago

try setting datacontext in codebehind/where oyu are creating the window

antimatter8189OP•2y ago

I did

    public partial class MainWindow : Window
    {
        double lastNumber, result;
        SelectedOperator selectedOperator;
        public MainWindow()
        {
            InitializeComponent();
            DataContext = new CalculatorVM();

            acButton.Click += AcButton_Click;
            negativeButton.Click += NegativeButton_Click;
            percentageButton.Click += PercentageButton_Click;
            equalButton.Click += EqualButton_Click;
        }

    public partial class MainWindow : Window
    {
        double lastNumber, result;
        SelectedOperator selectedOperator;
        public MainWindow()
        {
            InitializeComponent();
            DataContext = new CalculatorVM();

            acButton.Click += AcButton_Click;
            negativeButton.Click += NegativeButton_Click;
            percentageButton.Click += PercentageButton_Click;
            equalButton.Click += EqualButton_Click;
        }

didnt help either smth is quite odd here

ACiDCA7•2y ago

<Button x:Name="oneButton"
                Command="{Binding CalculateAndSaveCommand}"
                Style="{StaticResource numberButtonsStyle}"
                Content="1"
                Grid.Row="4"/>

<Button x:Name="oneButton"
                Command="{Binding CalculateAndSaveCommand}"
                Style="{StaticResource numberButtonsStyle}"
                Content="1"
                Grid.Row="4"/>

try this

hengi•2y ago

Should be called CalculateAndSaveCommand

antimatter8189OP•2y ago

I have this code in place, it does nothing

ACiDCA7•2y ago

like hengi said Command is missing in the binding name dont change the methodname tho just where you are binding

antimatter8189OP•2y ago

@ACiDCA7 , @hengi : https://github.com/KostaKing/Calculator

GitHub

GitHub - KostaKing/Calculator

Contribute to KostaKing/Calculator development by creating an account on GitHub.

antimatter8189OP•2y ago

look at line 100 at the xaml i got it It doesnt work the breakpoint isn't being activated in the command

hengi•2y ago

The CalculatorVM needs to be partial so it can generate the code And add it to the class

antimatter8189OP•2y ago

meaning?

    public partial class CalculatorVM: ObservableObject

    public partial class CalculatorVM: ObservableObject

whats next still doesnt work

hengi•2y ago

Try to run it and see if there are binding errors Unless you set the design time type of the data context (don't remember exactly what it's called) it will not autocomplete and might give you a warning

antimatter8189OP•2y ago

Nothing shows up, btw you do have the full repo the codebase is rly simple , just trying to convert it to using mvvm u can run it on your own machine, press 1 and see nothing happens it just doesnt go in the method

hengi•2y ago

1 sec

ACiDCA7•2y ago

grr i couldnt get it to work with the attribute aswell but if you go the "oldshool" way it works

antimatter8189OP•2y ago

but i dont wanna go oldschool lol thats the point why doesnt the attribute works? like tf 😄

hengi•2y ago

seems like the source generator doesn't work? need ilspy oof

antimatter8189OP•2y ago

im not on that lvl mate hah btw can u give code?

hengi•2y ago

yes it seems like .net 4.8 doesn't like the source generator of mvvm toolkit

antimatter8189OP•2y ago

thats interesting any fix?

ACiDCA7•2y ago

oh i didnt even check which target was set.. good point

antimatter8189OP•2y ago

yup am stuck on that 4.8

ACiDCA7•2y ago

public RelayCommand CalculateAndSaveCommand { get; set; }
        public CalculatorVM()
        {
            CalculateAndSaveCommand  = new RelayCommand(CalculateAndSave);
        }

public RelayCommand CalculateAndSaveCommand { get; set; }
        public CalculatorVM()
        {
            CalculateAndSaveCommand  = new RelayCommand(CalculateAndSave);
        }

add this to calculator vm

antimatter8189OP•2y ago

Yup That works but how do we make source generators work with 4.8?

ACiDCA7•2y ago

why are you stuck on net framework? you should not go in with the mindset that new features get backported to old runtimes

antimatter8189OP•2y ago

legacy project mate not my choice

hengi•2y ago

ohhhh

antimatter8189OP•2y ago

millions of lines of code wont be switched to .net core overnight

hengi•2y ago

you need to do right click on the calculator project and migrate to PackageReference it's packages.config not working

antimatter8189OP•2y ago

hengi sorry how do i migrate? what? give more details mate 😄

ACiDCA7•2y ago

hengi•2y ago

in the solution explorer in visual studio, expand your Calculator project, right click "References" and select "Migrate packages.config to PackageReference" also that, you need to set the LangVersion of the Project to at least 8..

ACiDCA7•2y ago

net framework is stuck on 7.3

antimatter8189OP•2y ago

yup it is

hengi•2y ago

it's not stuck, just edit the csproj

antimatter8189OP•2y ago

shit lol

ACiDCA7•2y ago

i dont think srcgens are included in latest but lemme try

hengi•2y ago

open the csproj with editor and add <LangVersion>9.0</LangVersion> under "TargetFrameworkVersion" works for me when migrated and the LangVersion manually added

antimatter8189OP•2y ago

hengi

in the solution explorer in visual studio, expand your Calculator project, right click "References" and select "Migrate packages.config to PackageReference"
also that, you need to set the LangVersion of the Project to at least 8..

in the solution explorer in visual studio, expand your Calculator project, right click "References" and select "Migrate packages.config to PackageReference"
also that, you need to set the LangVersion of the Project to at least 8..

after selecting refernces where do i find migrate packages.config?

hengi•2y ago

there's an article from Microsoft with screenshots: https://devblogs.microsoft.com/nuget/migrate-packages-config-to-package-reference/

The NuGet Blog

Migrate to PackageReference with 3 clicks - The NuGet Blog

Last year, we introduced the option to make PackageReference the default package management format for managing NuGet dependencies when installing the first NuGet package for a newly created projects. With Visual Studio Version 15.7 Preview 3, we have introduced the capability to migrate existing projects that use the packages.config format to u...

ACiDCA7•2y ago

indeed it does work

antimatter8189OP•2y ago

sec doing it

hengi•2y ago

to set the lang version: https://blog.ndepend.com/using-c9-record-and-init-property-in-your-net-framework-4-x-net-standard-and-net-core-projects/ you technically only need 8.0

ACiDCA7•2y ago

i was under the impression that the MS sourcegens were jsut for net5+.. well TIL

antimatter8189OP•2y ago

soz am kinda lost lol trying but

hengi•2y ago

it's actually .NET Standard 2.0 I guess..

antimatter8189OP•2y ago

no Default package management format exsist in the setting

antimatter8189OP•2y ago

referncing this: https://devblogs.microsoft.com/nuget/migrate-packages-config-to-package-reference/

The NuGet Blog

Migrate to PackageReference with 3 clicks - The NuGet Blog

hengi•2y ago

oh you only need to do the right click thing you don't need to change the setting

antimatter8189OP•2y ago

hhaha well i did any chance 1 of you gives me an updated repo that works? clearly above my head I just need to update the lang ver u saying?

hengi•2y ago

https://github.com/KostaKing/Calculator/pull/1

GitHub

migrate to PackageReference, set LangVersion to 8.0 by HengiFettlic...

hengi•2y ago

@AntiMatter you can either look at the branch or just merge, it's the new LangVersion and changing to ProjectReference

antimatter8189OP•2y ago

I merged jesus lol thank you so much i will go over what u did and learn from it

hengi•2y ago

np lol, we also have a project at work with .net 4.8 because of WCF, we'll probably never drop that it's good to know that source generators are indeed working

ACiDCA7•2y ago

meeh i was just about to create a quick gif how to do it..xD

antimatter8189OP•2y ago

do it would love to save it 😄 i just merged i dont know tf going on lol give me the fig gif*

ACiDCA7•2y ago

ACiDCA7•2y ago

hope you like it.. ignore that its in german^^

antimatter8189OP•2y ago

amazing dude thank you so much you 2 my gods will sacrifice goat tonight @ACiDCA7 @hengi 😄

Accord•2y ago

Was this issue resolved? If so, run /close - otherwise I will mark this as stale and this post will be archived until there is new activity.

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❔ Using mvvm toolkit- Why my view has no access to my command?

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