WPF TextBlock 元素和 Label 控件之间的区别是什么？

下面的两个代码片段可视化地生成相同的 UI。
Snippet1 

<TextBlock>Name:</TextBlock>
<TextBox Name="nameTextBox" />

Snippet2

<Label>Name:</Label>
<TextBox Name="nameTextBox" />

(好吧，我要自己回答这个问题... ... 我认为这是我今天从《编程 WPF 》中学到的一个有用的趣闻)

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Label has an important focus handling responsibility.Its purpose is to allow you to place a caption with an access key. It has a Target property, which indicates the target of the access key. Like this...

<Label Target="{Binding ElementName=nameTextBox}">_Name:</Label>
<TextBox x:Name="nameTextBox" />

In the absence of the Target property, the Label control does nothing useful. You'll just hear a beep if you press the access key indicating 'unable to process request'

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最佳答案

The WPF Textblock inherits from FrameworkElement instead of deriving from System.Windows.Control like the Label Control. This means that the Textblock is much more lightweight. The downside of using a textblock is no support for Access/Accerelator Keys and there is no link to other controls as target.

When you want to display text by itself use the TextBlock. The benefit is a light, performant way to display text.

When you want to associate text with another control like a TextBox use the Label control. The benefits are access keys and references to target control.

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Label can be used as an alternative to TextBlock for situations where minimal text support is required such as the label for a control. Using Label can be advantageous because it requires even less resources (lighter weight) then a TextBlock.

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With TextBlock we can easily have multi-line support I guess - using TextWrapping.

Using Label in such cases, e.g. displaying validation message, need to use <AccessKey> tags, which is less straight-forward than TextBlock.

On the other hand, using TextBlock not allow us to set the BorderBrush property.

So, to me, the two controls should be combined into a text-full-feature control.

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The two biggest reasons for the confusion regarding TextBlocks and Labels are Windows Forms and common sense.

  1. When you wanted to slap a small bit of text on your form in Windows Forms, you used a Label, so it follows (incorrectly) that you would do the same thing with a WPF Label.

  2. Common sense would lead you to believe that a Label is lightweight and a TextBlock isn't, when the opposite is true.

Note that you can put a TextBlock inside a Label.

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Label takes all kinds of data inputs like String, Number etc... TextBlock, as the name suggests, only accepts a Text string.


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