Asp.net MVC如何显示动态列 [英] Asp.net MVC how to display dynamic columns

问题描述

来自WebForms，我仍然是ASP.net MVC的新手。



我需要显示一个HTML表格，其中列在设计时未知。我有以下两个MS SQL表，它们表示将在运行时显示哪些列。

Coming from WebForms, I'm still brand new to ASP.net MVC.

I have a need to display a HTML table where the columns are unknown at design-time. I have the following two MS SQL tables which denote which columns will be displayed at runtime.

CREATE TABLE ActualData (
	Col1 int,
	Col2 int,
	Col3 int,
	Col4 int
)
INSERT INTO ActualData (Col1, Col2, Col3, Col4) VALUES (1, 2, 3, 4)

CREATE TABLE ColumnsToShow (
	UserID int,
	ColName varchar(10)
)
INSERT INTO ColumnsToShow(UserID, ColName) VALUES (1, 'Col1')
INSERT INTO ColumnsToShow(UserID, ColName) VALUES (1, 'Col2')
INSERT INTO ColumnsToShow(UserID, ColName) VALUES (2, 'Col3')
INSERT INTO ColumnsToShow(UserID, ColName) VALUES (2, 'Col4')

因此视图显示只有ActualData.Col1和ActualData.Col2到用户1，并且

ActualData.Col3和ActualData.Col4到用户2.



我知道在webforms中我可能会做这样的事情，在将数据表绑定到GridView控件之前删除匹配的列。

So that the view shows only ActualData.Col1 and ActualData.Col2 to user 1, and
ActualData.Col3 and ActualData.Col4 to user 2.

I know in webforms I would probably have done something like this, to remove matching columns before binding the datatable to a GridView control.

DataTable dtData = GetActualData(); // db call
List<string> colsToRemove = GetColumnsToRemove(); // db call returning only the fields to remove
// remove columns not neccessary for the current user
foreach (string colName in colsToRemove)
   foreach (DataColumn dc in dtData.Columns)
      if (dc.ColumnName == colName)
         dtData.Columns.Remove(colName);

// bind the datatable to a GridView
gridview.AutoGenerateColumns = true;
gridview.DataSource = dtData;
gridview.DataBind();

MVC的新手，我真的不知道从哪里开始。所以任何建议都会受到赞赏。



我尝试过：



还没有尝试任何东西，因为我正在寻找从哪里开始。

New to MVC, I really don't even know where to start. So any advice would be appreciated.

What I have tried:

Haven't tried anything yet, as I am looking for idea where to start.

推荐答案

你可能会想要使用 WebGrid助手 [ ^ ]：



ASP.NET MVC4中的WebGrid [ ^ ]

ASP.NET MVC中的WebGrid [ ^ ]

ASP.NET MVC的终极手册WebGrid | DanylkoWeb [ ^ ]



不幸的是，你需要定义列，因为 WebGrid 似乎无法为 DataTable 或 DataView 自动生成列。但这并不太难：

You're probably going to want to use the WebGrid helper[^]:

WebGrid in ASP.NET MVC4[^]
WebGrid in ASP.NET MVC[^]
The Ultimate Cookbook for the ASP.NET MVC WebGrid | DanylkoWeb[^]

Unfortunately, you'll need to define the columns, since the WebGrid doesn't seem to be able to auto-generate columns for a DataTable or DataView. But it's not too difficult:

var columns = new List<WebGridColumn>(dtData.Columns.Count);
foreach (DataColumn column in dtData.Columns)
{
    columns.Add(new WebGridColumn
    {
        ColumnName = column.ColumnName,
        Header = column.Caption,
    });
}

ViewBag.Columns = columns;
return View(dtData);

然后，在您看来：

Then, in your view:

@model DataTable

@{
    var grid = new WebGrid(Model);
}

@grid.GetHtml(columns: ViewBag.Columns)

或者，你可以将 DataTable 转换为动态对象列表，如此StackOverflow答案中所述 [ ^ ]。

Alternatively, you could convert your DataTable to a list of dynamic objects, as described in this StackOverflow answer[^].

var model = new List<dynamic>(dtData.Rows.Count);

foreach (DataRow row in dtData.Rows)
{
    var obj = (IDictionary<string, object>)new ExpandoObject();
    
    foreach (DataColumn col in dtData.Columns)
    {
        obj.Add(col.ColumnName, row[col]);
    }
    
    model.Add(obj);
}

return View(model);

然后，在您看来：

Then, in your view:

@model IList<dynamic>

@{
    var grid = new WebGrid(Model);
}

@grid.GetHtml()

谢谢理查德。我使用了动态列表版本。

像魅力一样工作： - ）

Thank you Richard. I used the dynamic list version.
Works like a charm :-)

我想动态地对列进行格式化

i want to agrigate column dynamicically

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