数据将枚举属性绑定到网格并显示描述

Question

这是一个类似于如何将自定义枚举描述绑定到DataGrid的问题,但在我的情况下,我有多个属性.

public enum ExpectationResult
{
    [Description("-")]
    NoExpectation,

    [Description("Passed")]
    Pass,

    [Description("FAILED")]
    Fail
}

public class TestResult
{
    public string TestDescription { get; set; }
    public ExpectationResult RequiredExpectationResult { get; set; }
    public ExpectationResult NonRequiredExpectationResult { get; set; }
}

我将BindingList <TestResult>绑定到WinForms DataGridView(实际上是DevExpress.XtraGrid.GridControl,但通用解决方案将更广泛适用).我希望描述出现而不是枚举名称.我怎么能做到这一点？(class/enum/attributes没有约束;我可以随意更改它们.)

Answer 1

A TypeConverter通常会做这个工作; 这里有一些适用的代码DataGridView- 只需添加代码来阅读描述(通过反射等 - 我现在只使用字符串前缀来显示自定义代码的工作原理).

请注意,您可能也想要覆盖ConvertFrom.可以在类型或属性级别指定转换器(如果您只希望它应用于某些属性),并且如果枚举不在您的控制之下,也可以在运行时应用.

using System.ComponentModel;
using System.Windows.Forms;
[TypeConverter(typeof(ExpectationResultConverter))]
public enum ExpectationResult
{
    [Description("-")]
    NoExpectation,

    [Description("Passed")]
    Pass,

    [Description("FAILED")]
    Fail
}

class ExpectationResultConverter : EnumConverter
{
    public ExpectationResultConverter()
        : base(
            typeof(ExpectationResult))
    { }

    public override object ConvertTo(ITypeDescriptorContext context,
        System.Globalization.CultureInfo culture, object value,
        System.Type destinationType)
    {
        if (destinationType == typeof(string))
        {
            return "abc " + value.ToString(); // your code here
        }
        return base.ConvertTo(context, culture, value, destinationType);
    }
}

public class TestResult
{
    public string TestDescription { get; set; }
    public ExpectationResult RequiredExpectationResult { get; set; }
    public ExpectationResult NonRequiredExpectationResult { get; set; }

    static void Main()
    {
        BindingList<TestResult> list = new BindingList<TestResult>();
        DataGridView grid = new DataGridView();
        grid.DataSource = list;
        Form form = new Form();
        grid.Dock = DockStyle.Fill;
        form.Controls.Add(grid);
        Application.Run(form);
    }
}

Answer 2

我不确定这有多大帮助,但我在Enum上使用了一个扩展方法,如下所示:

    /// <summary>
    /// Returns the value of the description attribute attached to an enum value.
    /// </summary>
    /// <param name="en"></param>
    /// <returns>The text from the System.ComponentModel.DescriptionAttribute associated with the enumeration value.</returns>
    /// <remarks>
    /// To use this, create an enum and mark its members with a [Description("My Descr")] attribute.
    /// Then when you call this extension method, you will receive "My Descr".
    /// </remarks>
    /// <example><code>
    /// enum MyEnum {
    ///     [Description("Some Descriptive Text")]
    ///     EnumVal1,
    ///
    ///     [Description("Some More Descriptive Text")]
    ///     EnumVal2
    /// }
    /// 
    /// static void Main(string[] args) {
    ///     Console.PrintLine( MyEnum.EnumVal1.GetDescription() );
    /// }
    /// </code>
    /// 
    /// This will result in the output "Some Descriptive Text".
    /// </example>
    public static string GetDescription(this Enum en)
    {
        var type = en.GetType();
        var memInfo = type.GetMember(en.ToString());

        if (memInfo != null && memInfo.Length > 0)
        {
            var attrs = memInfo[0].GetCustomAttributes(typeof(DescriptionAttribute), false);
            if (attrs != null && attrs.Length > 0)
                return ((DescriptionAttribute)attrs[0]).Description;
        }
        return en.ToString();
    }

您可以在对象上使用自定义属性getter来返回名称:

public class TestResult
{
    public string TestDescription { get; set; }
    public ExpectationResult RequiredExpectationResult { get; set; }
    public ExpectationResult NonRequiredExpectationResult { get; set; }

    /* *** added these new property getters *** */
    public string RequiredExpectationResultDescr { get { return this.RequiredExpectationResult.GetDescription(); } }
    public string NonRequiredExpectationResultDescr { get { return this.NonRequiredExpectationResult.GetDescription(); } }
}

然后将网格绑定到"RequiredExpectationResultDescr"和"NonRequiredExpectationResultDescr"属性.

这可能有点过于复杂,但它是我提出的第一件事:)