logo
Tags down

shadow

WinForms ComboBox data binding gotcha


By : tdowg1
Date : March 29 2020, 07:55 AM
help you fix your problem This has to do with how data bindings are set up in the dotnet framework, especially the BindingContext. On a high level it means that if you haven't specified otherwise each form and all the controls of the form share the same BindingContext. When you are setting the DataSource property the ComboBox will use the BindingContext to get a ConcurrenyMangager that wraps the list. The ConcurrenyManager keeps track of such things as the current selected position in the list.
When you set the DataSource of the second ComboBox it will use the same BindingContext (the forms) which will yield a reference to the same ConcurrencyManager as above used to set up the data bindings.
code :


Share : facebook icon twitter icon

Linq sql data binding to winforms combobox


By : user92363
Date : March 29 2020, 07:55 AM
wish help you to fix your issue Ok...Issue was traced to funky winform behavior. Evidently, there is no guarantee that the OnLoad for a user control will not be called more than once. As a consequence, the two tables involved, (see diagram above), were being loaded from different DataContexts. Splat!!

Data binding an Enum stored in an object into a Winforms ComboBox?


By : user1662712
Date : March 29 2020, 07:55 AM
I hope this helps you . You can use a two-way binding on the SelectedItem property of the ComboBox. When adding values to the combo box, be sure to add the enum values and not just strings that match their display name.
code :
comboBox.Items.Add(ConsoleColor.Red);
comboBox.Items.Add(ConsoleColor.Blue);
// ... etc
public partial class Form1 : Form {

    private Person p = new Person( );

    public Form1( ) {

        InitializeComponent( );

        comboBox1.DataSource = Enum.GetValues( typeof( Gender ) );

        textBox1.DataBindings.Add( "Text", p, "Name", false, DataSourceUpdateMode.OnPropertyChanged );
        comboBox1.DataBindings.Add( "SelectedItem", p, "Gender", false, DataSourceUpdateMode.OnPropertyChanged );

        label1.DataBindings.Add( "Text", p, "Name", false, DataSourceUpdateMode.Never );
        label2.DataBindings.Add( "Text", p, "Gender", false, DataSourceUpdateMode.Never );

    }
    private void Form1_Load( object sender, EventArgs e ) {
        // yeah, that's right i voted for him,
        // go ahead and downvote me
        p.Name = "John McCain";
        p.Gender = Gender.Male;
    }
    private void Form1_Click( object sender, EventArgs e ) {
        p.Name = "Sarah Palin";
        p.Gender = Gender.Female;
    }
}

public enum Gender {
    Male,
    Female
}

public class Person : INotifyPropertyChanged {

    private string name;
    private Gender gender;

    public string Name
    {
        get { return name; }
        set {
            name = value;
            PropertyChanged( this, new PropertyChangedEventArgs( "Name" ) );
        }
    }

    public Gender Gender {
        get { return gender; }
        set {
            gender = value;
            PropertyChanged( this, new PropertyChangedEventArgs( "Gender" ) );
        }
    }

    public event PropertyChangedEventHandler PropertyChanged = delegate {};

} 

Binding Label and Value to ComboBox Winforms


By : Angelo Ruggiero
Date : March 29 2020, 07:55 AM
this will help You can bind a dictionary to a datasource by using the ToList() method of the dictionary.
Edit
code :
LvName.DataSource = itemValue.ToList()
LvName.DisplayMember = "Value"
LvName.ValueMember = "Key"

Linq-to-sql to Combobox binding (Winforms)


By : seco yah
Date : March 29 2020, 07:55 AM
should help you out The selected item of a combobox is the current object in its data source, in this case: a User. You must use SelectedValue:
code :
comboBoxAssessor.DataBindings.Add("SelectedValue", _comment, "UserId");

Winforms ComboBox User Control Binding


By : Williams Douglas
Date : March 29 2020, 07:55 AM
I wish this helpful for you http://social.msdn.microsoft.com/forums/vstudio/en-US/3e35b534-7d3f-4832-8859-b5cb838bd62a/extended-combobox-adds-items-twice
code :
public partial class CheckSeriesBox : ComboBox
{
    private static List<string> CheckSeries;

    public CheckSeriesBox()
    {
        InitializeComponent();

        CheckSeries = new List<string>();
        SetCheckSeries();

        if (DesignMode)
        {
             this.Items.AddRange(CheckSeries.ToArray());
        }
    }

    public static List<string> SetCheckSeries()
    {
        CheckSeries.Add("A");
        CheckSeries.Add("B");
    }

    protected new bool DesignMode
    {
        get
        {
            if (base.DesignMode)
            {
                return true;
            }
            else
            {
                Control parent = this.Parent;
                while ((parent != null))
                {
                    System.ComponentModel.ISite site = parent.Site;
                    if ((site != null) && site.DesignMode)
                    {
                        return true;
                    }
                    parent = parent.Parent;
                }
                return false;
            }
        }
    }

}
Related Posts Related Posts :
  • How to check whether string contains specific string in c#
  • UPnP hole punching can't use external IP to access device on local subnet
  • Is there a way to use a conditional when declaring method variables?
  • c# interop Excel - disable or remove automatic page breaks
  • How can I read in these commands from a file using?
  • Pinch and rotate around a point using MRTK and Hololens 1
  • Enhance performance to paint image, is SIMD perhapse a solution?
  • Which one has better performance, data types .NET or alias name data types C#?
  • HttpClient GetAsync taking ~2 seconds
  • linq fastest where method
  • Why can I read more than 254 characters with Console.ReadLine when the docs suggest that I shouldn't be able to?
  • C# - Delayed execution for a collection of items
  • How to display images in a CollectionView from a Base64 string?
  • Convert class object to class index
  • c# identifier expected in controller
  • Subscribe to multiple Observables and gets notified on the same thread
  • how to create windows service using crud operations in c# asp.net
  • Iterating through list of values in a dictionary c#
  • How to Implement Expo.io Push Notifications Send Through C#
  • Gridview columns not being set to width I enter
  • Impersonate User with Forms Authorization
  • ASP.NET MVC Impersonate not working with Forms Authentication
  • Found a potential bug in Moq library while selecting a constructor
  • I want to show a list but page is empty
  • Can this kind of concurrency problem be solved with async/await?
  • Yield keyword giving unexpected values for IEnumerable
  • Many DLLs in System namespace are included when installing library via Nuget
  • C# - range for textbox inputs
  • the Console.ReadLine() Doesn't set the string as the user input
  • Get notified when a variable changed
  • How to list players in room in Photon?
  • Link compile-time created resources to a class library
  • How to quickly choose numbers and weights in such a way as to obtain a specific weighted sum?
  • Downgrade .Net Core project from 3.1 to 2.2 - The type or namespace name 'IWebHostEnvironment' could not be found
  • c# multiplying array elements using system.numerics
  • Private methods vs local functions
  • C# project wants .NET 4.7.1 but I can't install it
  • Binding to object itself, doesn't update when individual property changes
  • remove duplicate from list in object c#
  • JSON.NET - find JObject by value regex in complex object?
  • Save an unknown sized array from unknown string length
  • Camera not centre on player sprite (monogame)
  • How to set a default type for T in a static generic method?
  • How can I insert multiple items of data into SQL using Web API?
  • Finding longest time in an array
  • How to find two quotation marks in a string
  • X509Certificate2 certification issue
  • Image format change in Azure
  • Why is there such big time difference in searching for element with higher index in ConcurrentBag?
  • Async Lambda Issue
  • C# SSIS Script Task - Add Thousand Seperator when formatting Excel column
  • How to check if a textbox starts with numeric value
  • c# Strange Pairs || I can't spot the difference between these 2 solutions?
  • str.Split(".") not working in C# interactive window but work in C# .Net core project?
  • How to do 3 conditions with if else C#
  • merge two lists of same type in c#
  • Blazor - SortBy parameter for table column component
  • InvalidCastException: Specified cast is not valid Error when tried to fetch image from url
  • Search based on Properties
  • Ref string parameter is empty?
  • shadow
    Privacy Policy - Terms - Contact Us © voile276.org