Name can also be set using property element syntax with inner text, but that is uncommon. In contrast, x:Name cannot be set in XAML property element syntax, or in code using SetValue; it can only be set using attribute syntax on objects because it is a directive. If Name is available as a property on the class, Name and x:Name can be used interchangeably as attributes, but a parse exception will result if both are specified on the same element. If the XAML is markup compiled, the exception will occur on the markup compile, otherwise it occurs on load.

它们都是一样的东西，很多框架元素本身公开了name属性，但对于那些不公开的元素，你可以使用x:name -我通常只使用x:name，因为它适用于任何东西。

控件可以将名称本身公开为依赖属性(因为它们需要在内部使用该依赖属性)，也可以选择不这样做。

更多细节在msdn这里和这里:

Some WPF framework-level applications might be able to avoid any use of the x:Name attribute, because the Name dependency property as specified within the WPF namespace for several of the important base classes such as FrameworkElement/FrameworkContentElement satisfies this same purpose. There are still some common XAML and framework scenarios where code access to an element with no Name property is necessary, most notably in certain animation and storyboard support classes. For instance, you should specify x:Name on timelines and transforms created in XAML, if you intend to reference them from code. If Name is available as a property on the class, Name and x:Name can be used interchangeably as attributes, but an error will result if both are specified on the same element.

这不是一个WPF项，而是一个标准的XML项，BtBh已经正确地回答了它，x指的是默认的名称空间。在XML中，如果不给元素/属性加上名称空间前缀，则假定您需要默认名称空间。 因此，只输入Name只不过是x:Name的缩写。关于XML名称空间的更多细节可以在链接文本中找到

The specified x:Name becomes the name of a field that is created in the underlying code when XAML is processed, and that field holds a reference to the object. In Silverlight, using the managed API, the process of creating this field is performed by the MSBuild target steps, which also are responsible for joining the partial classes for a XAML file and its code-behind. This behavior is not necessarily XAML-language specified; it is the particular implementation that Silverlight applies to use x:Name in its programming and application models.

阅读更多关于MSDN…

当您在XAML中声明Button元素时，您引用的是在windows运行时中定义的一个名为Button的类。

按钮有很多属性，如背景，文本，边距，.....和一个名为Name的属性。

现在，当您在XAML中声明一个Button时，就像创建一个匿名对象，该对象碰巧有一个名为Name的属性。

一般来说，你不能引用一个匿名对象，但是在WPF框架中，XAML处理器允许你通过给Name属性的任何值来引用该对象。

到目前为止一切顺利。

创建对象的另一种方法是创建命名对象而不是匿名对象。在这种情况下，XAML名称空间有一个名为Name的对象属性(由于它在XAML名称空间中，因此有X:)，您可以设置该属性，以便识别对象并引用它。

结论:

Name是特定对象的属性，但X:Name是该对象的一个属性(有一个类定义了一个通用对象)。

X:如果有自定义控件，Name可能会导致内存问题。它将为NameScope条目保留一个内存位置。

我建议除非迫不得已，否则不要使用x:Name。