数据注释和WPF验证 [英] Data annotation and wpf validation

问题描述

有什么方法可以将数据注释用作WPF中的验证来源？我希望能够定义一个类，例如：

Is there any way that I use data annotation as the source of validation in WPF? I want to be able to define a class such as:

class myData
{
    [Required]
    [MaxLength(50)]
    public string Name{get;set;}
}

然后将其绑定到视图中的字段，并且wpf验证用户为此字段输入了一些值，并确保其长度不大于50。我知道我可以编写一个验证器为此，但是如果我将maxLength更改为60，则需要在验证器中进行更改，并且我不想在其他位置进行更改。

And then bind it to a field in a view and the wpf validate that user enter some value for this field and also make sure that its length is not greater than 50. I know that I can write a validator for this, but then if I change the maxLength to say 60, then I need to change it in validator and I don't want to have changes in different places.

推荐答案

您需要创建该类的元数据定义。您将需要以下内容：

You need to create a "metadata" definition of the class. You'll need something like this:

[MetadataTypeAttribute(typeof(MyClass.MyClassMetadata))]
public partial class MyClass
{
    internal sealed class MyClassMetadata
    {
        // Metadata classes are not meant to be instantiated.
        private MyClassMetadata()
        {
        }

        [Required]
        [MaxLength(50)]
        public string Name{ get; set; }
    }
}

此类将必要的元数据扩展为支持验证。

This extends the class with the necessary meta data to support the validation.

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