dcsimg
Results 1 to 15 of 15
  1. #1

    Thread Starter
    Junior Member
    Join Date
    Dec 2016
    Posts
    20

    Resolved [RESOLVED] How to prevent a TabItem from being selected

    There is no TabControl.Selecting Event in the WPF while there is in the Winform as you can see following.
    https://msdn.microsoft.com/en-us/lib...v=vs.110).aspx


    I have found following source for this issue.
    https://joshsmithonwpf.wordpress.com...eing-selected/

    Code:
    public Window1()
    {
         InitializeComponent();
    
         base.DataContext = new DataSource();
    
         var items = new string[] { "A", "B", "C" };
         this.tab.ItemsSource = items;
         var collView = CollectionViewSource.GetDefaultView(items);
         collView.CurrentChanging += this.OnTabItemSelecting;
    }
    
    void OnTabItemSelecting(object sender, CurrentChangingEventArgs e)
    {
         bool allow = this.chk.IsChecked.GetValueOrDefault();
         if (!allow)
         {
              // SelectedContent hasn't changed yet, so use it to figure out
              // the index of the previously selected tab
              int prevIdx = this.tab.Items.IndexOf(this.tab.SelectedContent);
              this.tab.SelectedIndex = prevIdx;
         }
    }

    Converted code via http://converter.telerik.com/;

    Code:
    Public Sub Window1()
        InitializeComponent()
        MyBase.DataContext = New DataSource()
        Dim items = New String() {"A", "B", "C"}
        Me.tab.ItemsSource = items
        Dim collView = CollectionViewSource.GetDefaultView(items)
        collView.CurrentChanging += AddressOf Me.OnTabItemSelecting
    End Sub
    
    Private Sub OnTabItemSelecting(ByVal sender As Object, ByVal e As CurrentChangingEventArgs)
        Dim allow As Boolean = Me.chk.IsChecked.GetValueOrDefault()
        If Not allow Then
            Dim prevIdx As Integer = Me.tab.Items.IndexOf(Me.tab.SelectedContent)
            Me.tab.SelectedIndex = prevIdx
        End If
    End Sub
    But I have no idea how that vb.net code works.

    So, please somebody explain me how that vb.net code works in WPF.
    Last edited by Kram Kramer; Feb 26th, 2018 at 01:19 AM.

  2. #2
    .NUT jmcilhinney's Avatar
    Join Date
    May 2005
    Location
    Sydney, Australia
    Posts
    98,631

    Re: How to prevent a TabItem from being selected

    There are lots of code converters around the web. Try using one or more of them and then, if you have any issues, we can help you fix them.

    Alternatively, download Instant VB from Tangible Software Solutions. There's a free version and it will likely produce an error-free result.
    Why is my data not saved to my database? | MSDN Data Walkthroughs
    VBForums Database Development FAQ
    My CodeBank Submissions: VB | C#
    My Blog: Data Among Multiple Forms (3 parts)
    Beginner Tutorials: VB | C# | SQL

  3. #3

    Thread Starter
    Junior Member
    Join Date
    Dec 2016
    Posts
    20

    Re: How to prevent a TabItem from being selected

    I tried http://converter.telerik.com/.
    But converted code doesnt work.

  4. #4
    .NUT jmcilhinney's Avatar
    Join Date
    May 2005
    Location
    Sydney, Australia
    Posts
    98,631

    Re: How to prevent a TabItem from being selected

    Quote Originally Posted by Kram Kramer View Post
    But converted code doesnt work.
    Did you miss this part of my previous post:

    if you have any issues, we can help you fix them.
    I'm not seeing where you've provided any information about those issues. If you want use to help you with conversion issues then you should be providing the original code (as formatted text in your post, not an off-site image) and the converted code, along with specific details of what "doesn't work" actually means so that we have an idea what to look for. That's how you help us help you.

    Alternatively, download Instant VB from Tangible Software Solutions. There's a free version and it will likely produce an error-free result.
    Did you try that?
    Why is my data not saved to my database? | MSDN Data Walkthroughs
    VBForums Database Development FAQ
    My CodeBank Submissions: VB | C#
    My Blog: Data Among Multiple Forms (3 parts)
    Beginner Tutorials: VB | C# | SQL

  5. #5

    Thread Starter
    Junior Member
    Join Date
    Dec 2016
    Posts
    20

    Re: How to prevent a TabItem from being selected

    @jmcilhinney

    I have updated my question.

  6. #6
    .NUT jmcilhinney's Avatar
    Join Date
    May 2005
    Location
    Sydney, Australia
    Posts
    98,631

    Re: How to prevent a TabItem from being selected

    For one thing, the first method is a constructor, so the code it contains should be put into the New sub in your VB window, because that's the constructor. Also, does your window contain a TabControl named 'tab'?
    Why is my data not saved to my database? | MSDN Data Walkthroughs
    VBForums Database Development FAQ
    My CodeBank Submissions: VB | C#
    My Blog: Data Among Multiple Forms (3 parts)
    Beginner Tutorials: VB | C# | SQL

  7. #7

    Thread Starter
    Junior Member
    Join Date
    Dec 2016
    Posts
    20

    Re: How to prevent a TabItem from being selected

    xaml

    Code:
    <Window x:Class="MainWindow"
      xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
            xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
            Title="TabControlSample" Height="200" Width="250">
        <Grid>
            <TabControl x:Name="tab">
                <TabItem Header="General">
                    <Label Content="Content goes here..." />
                </TabItem>
                <TabItem Header="Security" />
                <TabItem Header="Details" />
            </TabControl>
        </Grid>
    </Window>
    vb

    Code:
    Class MainWindow 
        Public Sub Window1()
            InitializeComponent()
            MyBase.DataContext = New DataSource()
            Dim items = New String() {"A", "B", "C"}
            Me.tab.ItemsSource = items
            Dim collView = CollectionViewSource.GetDefaultView(items)
            collView.CurrentChanging += AddressOf Me.OnTabItemSelecting
        End Sub
    
        Private Sub OnTabItemSelecting(ByVal sender As Object, ByVal e As CurrentChangingEventArgs)
            Dim allow As Boolean = Me.chk.IsChecked.GetValueOrDefault()
            If Not allow Then
                Dim prevIdx As Integer = Me.tab.Items.IndexOf(Me.tab.SelectedContent)
                Me.tab.SelectedIndex = prevIdx
            End If
        End Sub
    
    End Class
    Picture which shows errors https://prnt.sc/ijtvm4
    Attached Images Attached Images  

  8. #8
    .NUT jmcilhinney's Avatar
    Join Date
    May 2005
    Location
    Sydney, Australia
    Posts
    98,631

    Re: How to prevent a TabItem from being selected

    So, you're just ignoring the bit about the constructor? Create an appropriate window, i.e. a window with the appropriate control(s) and then add a constructor to the code. Next, copy the code from the first method (which is a constructor in the C# code) and then copy the second method (the event handler) as is. If you still have issues, please describe them clearly. Don't post screenshots. Post the code, highlight the lines that are at issue and describe the issues, which means providing error messages if there are any.
    Why is my data not saved to my database? | MSDN Data Walkthroughs
    VBForums Database Development FAQ
    My CodeBank Submissions: VB | C#
    My Blog: Data Among Multiple Forms (3 parts)
    Beginner Tutorials: VB | C# | SQL

  9. #9

    Thread Starter
    Junior Member
    Join Date
    Dec 2016
    Posts
    20

    Re: How to prevent a TabItem from being selected

    @jmcilhinney
    I am very fresh in vb.net programming.
    So, I need completed code which is ready to run.
    Because I have no idea what you mean

  10. #10
    .NUT jmcilhinney's Avatar
    Join Date
    May 2005
    Location
    Sydney, Australia
    Posts
    98,631

    Re: How to prevent a TabItem from being selected

    If all you're going to do is copy code from elsewhere then that's your prerogative but that's not programming, so I'm not much interested in helping you do that. If you want to learn how to program then you actually need to learn the basics first and then apply them. People should be able to use terms like class, method, property, constructor, event, etc and you should know what they mean or know how to find out. We shouldn't have to teach the basics each time we answer a specific question. As I said, what you do is up to you but if you want to jump in without a decent grounding in the fundamentals then you're going to get stuck on easy stuff and I don't see it as my job to help people with the easy stuff that they can find for themselves without much effort. I want to help with the hard stuff that people have attempted but can't get on their own. How to write a constructor doesn't fall into that category as far as I'm concerned. Others may feel differently and you're welcome to wait and see if someone else does, but It would be a good idea to research the fundamentals in the mean time.
    Why is my data not saved to my database? | MSDN Data Walkthroughs
    VBForums Database Development FAQ
    My CodeBank Submissions: VB | C#
    My Blog: Data Among Multiple Forms (3 parts)
    Beginner Tutorials: VB | C# | SQL

  11. #11

    Thread Starter
    Junior Member
    Join Date
    Dec 2016
    Posts
    20

    Re: How to prevent a TabItem from being selected

    I have searched for constructors in the web.
    Constructors are very difficult for me to understand.
    So, I need completed code which is ready to run.

  12. #12
    .NUT jmcilhinney's Avatar
    Join Date
    May 2005
    Location
    Sydney, Australia
    Posts
    98,631

    Re: How to prevent a TabItem from being selected

    So you spent less than 22 minutes researching constructors and decided that it was too hard? I'll leave you to it.
    Why is my data not saved to my database? | MSDN Data Walkthroughs
    VBForums Database Development FAQ
    My CodeBank Submissions: VB | C#
    My Blog: Data Among Multiple Forms (3 parts)
    Beginner Tutorials: VB | C# | SQL

  13. #13

    Thread Starter
    Junior Member
    Join Date
    Dec 2016
    Posts
    20

    Re: How to prevent a TabItem from being selected

    I dont think constructors are difficult.
    Code from https://joshsmithonwpf.wordpress.com...eing-selected/ is so difficult for newbies like me.
    You can help me, I trust you

  14. #14
    Frenzied Member KGComputers's Avatar
    Join Date
    Dec 2005
    Location
    Cebu, PH
    Posts
    1,907

    Re: How to prevent a TabItem from being selected

    Based from the screenshot provided, you need to import the System.ComponentModel namespace to use the CurrentChangingEventArgs class and make sure to add a checkbox control with name chk in your XAML since it's looking for that control which does not exist in your XAML.

    - kgc
    CodeBank: VB.NET & C#.NET | ASP.NET
    Programming: C# | VB.NET
    Blogs: Personal |Programming | GitHub
    ___________________________________________________________________________________

    Rating someone's post is a way of saying Thanks...

  15. #15

    Thread Starter
    Junior Member
    Join Date
    Dec 2016
    Posts
    20

    Re: How to prevent a TabItem from being selected

    Solved by myself.

    Code:
    Class MainWindow
    PublicSubNew()
            InitializeComponent()
            Me.tab.ItemsSource=NewString(){"A","B","C"}
            AddHandler tab.SelectionChanged,AddressOfOnTabItemSelecting
        EndSub
        PrivateSubOnTabItemSelecting(ByVal sender AsObject,ByVal e AsSelectionChangedEventArgs)
            Dim allow AsBoolean=Me.chk.IsChecked.GetValueOrDefault()
            IfNot allow Then
                Dim prevIdx AsInteger=Me.tab.Items.IndexOf(Me.tab.SelectedContent)
                Me.tab.SelectedIndex= prevIdx
            EndIf
        EndSub
    EndClass

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  



Featured


Click Here to Expand Forum to Full Width