如何在ASP.NET MVC中使布尔HTML5属性“条件化”？

Question

我正在使用ASP.NET MVC(5.2.3.0)创建一个表单字段：

@Html.TextBoxFor(
    x => x.UserName, 
    new { 
        @class = "form-control", 
        placeholder = "Enter your username", 
        required = true, 
        autofocus = true 
});

autofocus = String.IsNullOrEmpty(this.Model.UserName)
autofocus = String.IsNullOrEmpty(this.Model.UserName) ? null : ""`

有人知道怎么解决这个问题吗？

Answer 1

您可以在视图之前的某个地方创建属性字典：

@{
    var usernameAttrs = new Dictionary<string, object>
    {
        {"class ", "form-control"},
        {"placeholder  ", "Enter your username"},
        {"required", true},
    };

    if (String.IsNullOrEmpty(this.Model.UserName))
    {
        usernameAttrs.Add("autofocus", true);
    }
}

并在textboxfor()中使用

@Html.TextBoxFor(x => x.UserName, usernameAttrs);