Question

我在Stack Overflow上找到了这个，但没有我能得到答案的地方。

我想将数据网格的ComboBox绑定到property of a class，返回[Enum Value之一]。

MyEnum
{
    [StringValue("SomeVal")]
    SomeVal,
    [StringValue("AnotherVal")]
    AnotherVal,
    [StringValue("OneMoreVal")]
    OneMoreVal
}

class MyClass
{
    public MyEnum A_Value
    {
        return whatever; // whatever is MyEnum type
    }
}

现在我创建了一个带有组合框的数据网格列，我需要绑定一个属性

myCombo.DataSource = Enum.GetValues(typeof(MyEnum)); 
myCombo.DataBindings.Add("SelectedValue", myDataSource, bindingPath + ".A_Value");

当我运行此代码时，它失败并显示错误

“无法为没有ValueMember的组合框设置值”

然后我添加以下行

myCombo.ValueMember = "Value";

这次没有失败，但没有设置选定的值。 有人可以帮我解决这个问题吗？

我所说的：

Answer 1

我假设myDataSource应该是MyClass的实现...这是一个如何对其进行数据绑定的示例。它有点冗长，但也许有人可以改进它。

public partial class Form2 : Form
{
    private MyClass one;
    private Label label1;
    private ComboBox comboBox1;
    private FlowLayoutPanel panel;
    private Button btn1;
    public Form2()
    {
        InitializeComponent();

        one = new MyClass();
        panel = new FlowLayoutPanel();
        label1 = new Label();
        comboBox1 = new ComboBox();
        btn1 = new Button();
        btn1.Text = "Click to change Property";
        btn1.Click += (sender, args) => { one.A_Value = MyEnum.BtnVal; }; // to test binding to the property

        panel.Dock = DockStyle.Fill;

        Controls.Add(panel);
        panel.Controls.Add(comboBox1);
        panel.Controls.Add(label1);
        panel.Controls.Add(btn1);

        comboBox1.SelectedIndexChanged += (sender, args) =>
        {
            one.A_Value = (MyEnum)(sender as ComboBox).SelectedItem; // update the object when the ComboBox is changed
        };

        comboBox1.DataSource = Enum.GetValues(typeof(MyEnum));
        comboBox1.DataBindings.Add("SelectedItem",one,"A_Value"); // update the ComboBox if the Property is changed by something else
        label1.DataBindings.Add("Text",one,"A_Value"); // to show that changes happen to the property and not just the ComboBox
    }



}

public enum MyEnum
{
    [Description("SomeVal")]
    SomeVal,
    [Description("AnotherVal")]
    AnotherVal,
    [Description("OneMoreVal")]
    OneMoreVal,
    [Description("ButtonClickedValue")]
    BtnVal
}

public class MyClass : INotifyPropertyChanged
{
    private MyEnum whatever;

    public MyEnum A_Value
    {
        get { return whatever; } 
        set { whatever = value;
            PropertyChanged(this, new PropertyChangedEventArgs("A_Value"));
        }
    }

    public event PropertyChangedEventHandler PropertyChanged = delegate { };
}

Answer 2

据我所知，您的datagridview已绑定到MyClass列表如果您使用DataGridViewComboBoxColumn类型，请使用属性DatPropertyName。

'Use property name of your class to where combobox will be binding
myCombo.DataPropertyName = "A_Value"

然后在myCombo.DataSource = Enum.GetValues(typeof(MyEnum));之后如果instanceOf MyClass.A_Value的值将在组合框的数据源中它被显示出来。

<强>更新如果您使用普通ComboBox控件，则需要指定ValueMember属性

myCombo.ValueMember = "A_Value";

检查物业名称是否正确。因为在你质疑它是错误的。

如何将Enum绑定到DataGrid中的ComboBox

2 个答案: