在设计视图中必需标志控制属性 [英] Flag control properties as required in design view

问题描述

我想强制控制的消费者给予的属性放置在页面上控制时的值。

I'd like to force the consumer of a control to give a property a value when placing the control on a page.

在VisualStudio中，当你创建一个＆LT;而对用户控件属性SRC或ALT img>标签时，它会强调说，SRC和ALT需要的属性。我以为这只是在编辑器中的标签的特殊处理，但有没有办法来定义控制的类似行为？

In VisualStudio when you create an < img > tag without attributes SRC or ALT on a user control, it gets underlined saying that SRC and ALT are required attributes. I assume this is just a special handling of the tag by the editor, but is there a way to define a similar behavior for controls?

如果控制过这样定义的属性：

If the control had a property defined like this:

public object AProperty
{
    get 
    {
        if (ViewState["AProperty"] == null)
        {
            throw new Exception("AProperty is a required property of this control");
        }
        return ViewState["AProperty"];
    }
    set { ViewState["AProperty"] = value; }
}

有没有办法使用自定义属性或别的东西，一个办法是标志设计？

Is there a way to use a Custom Attribute or something else that would flag in the designer?

推荐答案

您可以使用Microsoft.Build.Framework.Required属性。这需要一个值在构建时要设定或构建将失败，表明该属性没有一个值的消息。

You could use the Microsoft.Build.Framework.Required attribute. This would require a value to be set at build time or the build will fail with a message which indicates that the property does not have a value.

我不相信这是表示一个特定的标签必须包含在一个服务器控件（或至少我没有看到对System.Web.UI.HtmlControl.Image类中的任何这样的属性）的属性。我认为，痘痘下划线是IDE的HTML验证的一部分。

I don't believe there is an attribute to indicate that a specific tag must be included in a server control (or at least I don't see any such attribute on the System.Web.UI.HtmlControl.Image class). I believe that the litle underlines are part of the HTML validation of the IDE.

您可以随时创建，如果属性缺失会抛出一个警告的自定义属性

You could always create a custom attribute which throws a warning if a property is missing

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