Winforms ComboBox-Binding DisplayMember zu Unterobjekt-Eigenschaft

Nur Hinzugefügt, um den code-Methode (Ereignis), und es funktioniert.

public partial class Form1 : Form
{
    private List<UserDataModel> userData = new List<UserDataModel>();
    public Form1()
    {
        InitializeComponent();

        MyInit();
    }

    public void MyInit()
    {
        var userDataModel1 = new UserDataModel();
        userDataModel1.Name = "Mike";
        userDataModel1.Phone = "555-666";
        userDataModel1.Home = new HomeDataModel();
        userDataModel1.Home.StreetName = "MikeStreet";
        userDataModel1.Home.GeoLocationX = 111;
        userDataModel1.Home.GeoLocationY = 222;

        var userDataModel2 = new UserDataModel();
        userDataModel2.Name = "Jonathan";
        userDataModel2.Phone = "777-888";
        userDataModel2.Home = new HomeDataModel();
        userDataModel2.Home.StreetName = "JonathanStreet";
        userDataModel2.Home.GeoLocationX = 333;
        userDataModel2.Home.GeoLocationY = 444;

        userData.Add(userDataModel1);
        userData.Add(userDataModel2);

        //This works as usually:
        /*
        comboBox1.DisplayMember = "Name";
        comboBox1.ValueMember = "Home";
        comboBox1.DataSource = userData;
        */

        //But this works not (either with comboBox1.DataBindings.Add() nor with BindingSource):
        comboBox1.DisplayMember = "Home.StreetName";
        comboBox1.ValueMember = "Home";
        comboBox1.DataSource = userData;

        //To drive me crazy, THAT shit works:
        textBox1.DataBindings.Add("Text", userData, "Home.StreetName");

        /*
        So how can i use a String-Property of a SubObject as ComboBox-DisplayMember ???

        BTW: To rebuild the sample, you only need a normal Forms Application and
        then drop a ComboBox and a TextBox on it. Copy that code here, and run it.
        */
    }

    //To add this method - follow to my instructions below
    private void ComboBoxFormat(object sender, ListControlConvertEventArgs e)
    {
        e.Value = ((UserDataModel)e.ListItem).Home.StreetName;
    }
}

internal sealed class UserDataModel
{
    public string Name { get; set; }
    public string Phone { get; set; }
    public HomeDataModel Home { get; set; }
}

internal sealed class HomeDataModel
{
    public string StreetName { get; set; }
    public int GeoLocationX { get; set; }
    public int GeoLocationY { get; set; }
}

Um diese Methode zu erstellen (event), gehen Sie zu Ihrer form in eine [Design] - Modus, Rechtsklick auf die ComboBox -> Eigenschaften.

In der Spitze des Eigenschaften-Fenster, klicken Sie auf Ereignisse (Blitz-Symbol),

Blick für das Format in der Liste Ereignisse unten (unter Eigenschaft Geändert hat), und geben Sie es einige event-Namen, sagen wir mal: ComboBoxFormat , und drücken Sie die EINGABETASTE.
Das ist es 😉

InformationsquelleAutor Eliran Kuta

Ok, ich habe die DisplayMember-arbeiten. Sie cant verwenden Sie die "Home" als ValueMember wie Ihr ein Objekt, müssen Sie an einem Punkt seiner Eigenschaften(StreetName, GeoLocationX, GeoLocationY).

public partial class Form1 : Form
    {

        private List<UserDataModel> userData = new List<UserDataModel>();

        public Form1()
        {
            InitializeComponent();
            MyInit();
        }

        public void MyInit()
    {
        var mymodel = new UserDataModel("Derek", "999-999", new HomeDataModel("Sesame Street", 111, 222));

        var mymodel1 = new UserDataModel("John", "999-999", new HomeDataModel("Tin Can Alley", 333, 444));

        userData.Add(mymodel);
        userData.Add(mymodel1);

        BindingSource bs = new BindingSource();
        bs.DataSource = userData;

        comboBox1.DataSource = bs;
        comboBox1.DisplayMember = "Home.StreetName";

    }
}

internal sealed class UserDataModel
{
    public string Name { get; set; }
    public string Phone { get; set; }
    public HomeDataModel Home { get; set; }

    public UserDataModel()
    {

    }

    public UserDataModel(string name, string phone, HomeDataModel home)
    {
        this.Name = name;
        this.Phone = phone;
        this.Home = home;
    }
}

internal sealed class HomeDataModel
{
    public string StreetName { get; set; }
    public int GeoLocationX { get; set; }
    public int GeoLocationY { get; set; }

    public HomeDataModel()
    {

    }

    public HomeDataModel(string streetname, int x, int y)
    {
        this.StreetName = streetname;
        this.GeoLocationX = x;
        this.GeoLocationY = y;

    }
}

InformationsquelleAutor Derek