MarkupExtension.ProvideValue - 是否IServiceProvider的实际使用？

问题描述

我要通过我的一些旧的代码并在混合的IValueConverter / 的MarkupExtension 类来了。这让我想知道如果的IServiceProvider 在 ProvideValue 方法实际上是有用的，以及它如何将是有益的？

我看到的IServiceProvider 只有一个方法：的GetService ，它必须被转换为合适的服务类型。我又看了看。

I was going through some old code of mine and came across a hybrid IValueConverter / MarkupExtension class. It got me wondering if the IServiceProvider in the ProvideValue method was actually useful, and how it would be useful?

I see that IServiceProvider only has one method: GetService, which must be cast to the proper service type. I also looked at the MarkupExtension.ProvideValue MSDN page and it lists different types of services. I guess, I'm just wondering if any of those services are useful or should I just leave my method as it is?

Current Method:

public Object ProvideValue(IServiceProvider serviceProvider)
{
    return new MyConverter();
}

Basically, should I do the following:

public Object ProvideValue(IServiceProvider serviceProvider)
{
    var provider = serviceProvider as SomeType;

    if (provider == null) return new MyConverter();

    //Do something with the provider here?
}

解决方案

If your MarkupExtension works without neeeding any interaction with the IServiceProvider then obviously there's nothing to be gained from accessing it. All MarkupExtension/ValueConverter combos I 've seen and written myself also fall into this category.

Moving on from practical matters, if you are just looking for reading material there's more information on what services the provider can make available and how they might be useful here.

这篇关于MarkupExtension.ProvideValue - 是否IServiceProvider的实际使用？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！