如果value为null，则在剃刀模板上放一个空字符串? [英] If value is null put an empty string on razor template?

问题描述

我有一个如下的剃刀模板.我想检查输入字段中的值是否为空，放置一个空字符串，如果@UIManager.Member.EMail有一个值，则放置它的值.我该怎么办?

I have a razor template like below. I want to check if the value in the input field is null, put a empty string, if the @UIManager.Member.EMail has a value, put its value. How can I do that?

正常输入:

<input name="EMail" id="SignUpEMail" type="text" class="Input" 
       value="@UIManager.Member.EMail" validate="RequiredField" />

剃刀语法尝试:

<input name="EMail" id="SignUpEMail" type="text" class="Input" validate="RequiredField"
       value="@(UIManager.Member == null) ? string.Empty : UIManager.Member.EMail" />

在输入字段中显示的值是:

The value is shown in the input field is:

True ? string.Empty : UIBusinessManager.MemberCandidate.EMail

推荐答案

如果您只想听这样的话:

If sounds like you just want:

@(UIManager.Member == null ? "" : UIManager.Member.Email)

请注意，括号的位置很重要；使用剃刀，@(....)为代码定义了一个显式范围-因此，括号内 之外的所有内容均被视为标记(不是代码).

Note the locations of the brackets is critical; with razor, @(....) defines an explicit range to the code - hence anything outside the brackets is treated as markup (not code).

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