數據注釋MVC

Question

僅當我的用戶名模型中有值時，才能添加必填字段。

我有：

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

我想要 ：

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

謝謝

Answer 1

好吧，您可以始終使用三元運算符?:來代替使用if語句?:

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

或者（如果將required設置設置為null不起作用），則可以向上使用它：

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

Answer 2

您可以簡單地使用

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

為什么需要使事情復雜化？