为什么下拉列表在一种情况下显示，而在另一种情况下不显示

Question

在我看来，当我这样做时，下拉列表显示正确-

@Html.DropDownListFor(m => m.SelectedEstimateState, Model.EstimateStateList.ToSelectList(c => c.Value, c => c.Text), new { });

但是当我这样做的时候没有-

@{
    Html.DropDownListFor(m => m.SelectedEstimateState, Model.EstimateStateList.ToSelectList(c => c.Value, c => c.Text), new { });
}

两者的区别是什么?

Answer 1

这是code block expression，用于计算表达式。但它没有写出来。更多信息请查看razor语法razor语法和web-programming-using-the-razor-syntax

@{
     Html.DropDownListFor(m => m.SelectedEstimateState, Model.EstimateStateList.ToSelectList(c => c.Value, c => c.Text), new { });
}

下面的Where将写出内容(基本上与经过编码的response.write()相同)

@Html.DropDownListFor(m => m.SelectedEstimateState, Model.EstimateStateList.ToSelectList(c => c.Value, c => c.Text), new { });