Question

我正在学习WPF而且我遇到了问题。我尝试在表单加载时初始化组合框数据，但我什么也没得到。这是我的代码：

XAML：

<Menu x:Name="mn_MainMenu" HorizontalAlignment="Left" Height="35" VerticalAlignment="Top" Width="518">
    <ComboBox Name="cbm_Menu" SelectedIndex="0" Width="340">
    </ComboBox>
    <Button HorizontalAlignment="Right" Content="Demo" Width="50"/>
    <Button HorizontalAlignment="Right" Content="Source Code" Width="80"/>
</Menu>

xaml.cs：

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
        InitCbxData(StaticVariable.ComboBoxData);
    }

    private void InitCbxData(string[] initStrings)
    {
        var comboBoxData = new ComboBoxData(initStrings);
        this.cbm_Menu.ItemsSource = comboBoxData.Items;
        this.cbm_Menu.DisplayMemberPath = "Name";
        this.cbm_Menu.SelectedValuePath = "Id";
        this.cbm_Menu.SelectedValue = "1";
    }
}

这是我在调试时的一个screeshot：

enter image description here

更新

 public class ComboBoxData:ItemCollection
    {
        public ComboBoxData(params string[] initStrings) : base(initStrings) { }
        public ComboBoxData(string initString, char[] delimiters) : base(initString, delimiters) { }
    }


public class Item
{
    public int Id;
    public string Name;

    public Item(int id, string name)
    {
        this.Id = id;
        this.Name = name;
    }
}


 public class ItemCollection : IEnumerable
{
    public Item[] Items;
    public int Ctr = 0;

    public ItemCollection(params string[] initStrings)
    {
        this.Items = new Item[initStrings.Count()];
        foreach (var s in initStrings)
        {
            this.Items[Ctr] = new Item(Ctr++, s);
        }
    }

    public ItemCollection(string initString, char[] delimiters)
    {
        string[] stringElements = initString.Split(delimiters);
        foreach (var s in stringElements)
        {
            this.Items[Ctr++] = new Item(Ctr, s);
        }
    }



    public IEnumerator GetEnumerator()
    {
        return new ItemCollectionEnumerator(this);
    }
}

public class ItemCollectionEnumerator : IEnumerator
{
    public int position = -1;
    public ItemCollection itemCollection;
    public ItemCollectionEnumerator(ItemCollection itemCollection)
    {
        this.itemCollection = itemCollection;
    }

    public object Current
    {
        get { return itemCollection.Items[position]; }
    }

    public bool MoveNext()
    {
        if (position < itemCollection.Items.Length - 1)
        {
            position++;
            return true;
        }
        else
        {
            return false;
        }
    }

    public void Reset()
    {
        position = -1;
    }
}

Answer 1

  private void InitCbxData(string[] initStrings)
    {
        var comboBoxData = new ComboBoxData(initStrings);
        this.cbm_Menu.ItemsSource = comboBoxData.Items;
        this.cbm_Menu.DisplayMemberPath = "Name";
        this.cbm_Menu.SelectedValuePath = "Id";
        this.cbm_Menu.SelectedValue = "1";
    }

我想这永远不会奏效。首先你收到一个字符串数组，因此，de DisplayMemberPath和SelectedValuePath没有“Name”或“Id”。

在我看来，你唯一需要做的就是

this.cbm_Menu.ItemsSource  = initstrings;

DisplayMemberPath和selectedValuePath应该用于具有ID和Name作为属性的对象....（适用于您的场景......）

Answer 2

问题解决了！

只需要在Item类中修改public field to property。我真的不知道为什么，但它确实有效！

修改为：

    public class Item
{
    public int Id {get;set;}
    public string Name {get;set;}

    public Item(int id, string name)
    {
        this.Id = id;
        this.Name = name;
    }
}

WPF ComboBox绑定不起作用

2 个答案: