CODEWITHSUNDEEP
c#vb.netxaml
busarider29
busarider29

Reputation: 305

Bind checkbox.ischecked to boolean property?

Can someone smarter than me please help with what should be a simple coding task: Binding .ischecked of a checkbox to a boolean property of an object? I have created a simple project to mimic what I'm trying to do in a larger project for simple debug and demonstration. I have a checkbox that when clicked sets a boolean property of my class object. Another checkbox on the UI should update its checked state based on the T/F value of that boolean property. What is wrong here and how to fix and just make it work? I "believe" the problem may be because I'm setting the property of a different object than what the checkbox.ischecked property is bound to (???). Is that the problem, and if so how do I remedy that? What code on the VB or XAML side needs to be implemented?

MainWindow.xaml.vb

Public Bools As New Boolean_Properties

Private Sub ckbx1_Click(sender As Object, e As RoutedEventArgs) Handles ckbx1.Click
    If ckbx1.IsChecked Then
        Bools.Sta1Mode = True
    Else Bools.Sta1Mode = False
    End If
End Sub

Class Boolean_Properties

Implements INotifyPropertyChanged
Private ModeSta1 As Boolean
Public Event ThePropertyChanged As PropertyChangedEventHandler Implements INotifyPropertyChanged.PropertyChanged

Property Sta1Mode As Boolean
    Get
        Return ModeSta1
    End Get
    Set(ByVal value As Boolean)
        ModeSta1 = value
        RaiseEvent ThePropertyChanged(Me, New PropertyChangedEventArgs("Sta1Mode"))
    End Set
End Property

XAML

<Window x:Class="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:local="clr-namespace:BindBooleanProperty"
    mc:Ignorable="d"
    xmlns:diag="clr-namespace:System.Diagnostics;assembly=WindowsBase"
    Title="MainWindow" Height="217.032" Width="226.067">
<Window.DataContext>
    <local:Boolean_Properties/>
</Window.DataContext>
<Grid>
    <CheckBox Content="Output" HorizontalAlignment="Left" Margin="99.866,134.399,0,0" VerticalAlignment="Top" IsChecked="{Binding Sta1Mode, Mode=OneWay}">
        <CheckBox.DataContext>
            <local:Boolean_Properties/>
        </CheckBox.DataContext>
    </CheckBox>
    <CheckBox x:Name="ckbx1" Content=" Input" HorizontalAlignment="Left" Margin="99.866,78.932,0,0" VerticalAlignment="Top"/>

</Grid>

Upvotes: 4

Views: 2359

Answers (1)

Tony
Tony

Reputation: 17637

You can use WPF Data Binding:
Instead of changing it using if, just bind the XAML interface and change the properties on the class.

Imports System.ComponentModel

Public Class Class1
    Implements INotifyPropertyChanged
    Public Event PropertyChanged As PropertyChangedEventHandler Implements INotifyPropertyChanged.PropertyChanged

    Private _ModeSta1 As Boolean
    Property ModeSta1 As Boolean
        Get
            Return _ModeSta1
        End Get
        Set(ByVal value As Boolean)
            _ModeSta1 = value
            RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs(NameOf(ModeSta1)))
        End Set
    End Property

End Class

Change the CheckBox to just Bind to the ModeSta1 property

<CheckBox x:Name="ckbx1" 
    Content=" Input" 
    Margin="99.866,78.932,0,0" 
    VerticalAlignment="Top" 
    HorizontalAlignment="Left" 
    IsChecked="{Binding Path=ModeSta1, Mode=TwoWay}" 
/>

When the value of ModeSta1 is changed, the User Interface is updated, and if user clicks the checkbox, the ModeSta1 value is changed as well.

    Dim c = New Class1
    DataContext = c
    ' You can change the property and this change will be visible on the UI
    c.ModeSta1 = True

CheckBox

Upvotes: 4

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