Question

如果我的用户名模型中有值，我该如何添加必填字段。

我有：

@Html.PasswordFor(
    model => model.Password, 
    new { required = "This field is required" }
)

我想：

@Html.PasswordFor(
    model => model.Password, 
    new { if (Model.UserName != null) {required = "This field is required"} }
)

谢谢

Answer 1

您可以使用三元运算符if

而不是使用?:语句

@Html.PasswordFor(
    model => model.Password, 
    new { required = Model.UserName != null ? "This field is required" : null }
)

或者（如果将required设置为null不起作用）那么你可以使用它一级：

@Html.PasswordFor(
    model => model.Password, 
    Model.UserName != null
        ? new { required = "This field is required" }
        : new { }
)

Answer 2

您只需使用

即可

if(Model.UserName != null) 
{
    @Html.PasswordFor(model => model.Password, new { required = "This fiels is required"})  
}
else
{
    @Html.PasswordFor(model => model.Password)
}

为什么你需要复杂化？

数据注释MVC

2 个答案: