ASP.NET GridView 第二个标题行跨越主标题行

Posted 2023-04-01

【中文标题】ASP.NET GridView 第二个标题行跨越主标题行

【英文标题】：ASP.NET GridView second header row to span main header row

【发布时间】：2010-09-23 19:19:21

【问题描述】：

我有一个 ASP.NET GridView，它的列如下所示：

| Foo | Bar | Total1 | Total2 | Total3 |

是否可以在两行上创建一个像这样的标题？

|           |  Totals   |    
| Foo | Bar | 1 | 2 | 3 |

每一行中的数据将保持不变，因为这只是为了美化标题并减少网格占用的水平空间。

在重要的情况下，整个 GridView 都是可排序的。我不打算让添加的“总计”跨越列具有任何排序功能。

编辑：

根据下面给出的一篇文章，我创建了一个继承自 GridView 的类，并在其中添加了第二个标题行。

namespace CustomControls

    public class TwoHeadedGridView : GridView
    
        protected Table InnerTable
        
            get
            
                if (this.HasControls())
                
                    return (Table)this.Controls[0];
                

                return null;
            
        

        protected override void OnDataBound(EventArgs e)
        
            base.OnDataBound(e);
            this.CreateSecondHeader();
        

        private void CreateSecondHeader()
        
            GridViewRow row = new GridViewRow(0, -1, DataControlRowType.Header, DataControlRowState.Normal);

            TableCell left = new TableHeaderCell();
            left.ColumnSpan = 3;
            row.Cells.Add(left);

            TableCell totals = new TableHeaderCell();
            totals.ColumnSpan = this.Columns.Count - 3;
            totals.Text = "Totals";
            row.Cells.Add(totals);

            this.InnerTable.Rows.AddAt(0, row);
        
    

如果您像我一样是 ASP.NET 新手，我还应该指出您需要：

1) 通过在您的网络表单中添加这样的一行来注册您的课程：

<%@ Register TagPrefix="foo" NameSpace="CustomControls" Assembly="__code"%>

2) 将之前标记中的 asp:GridView 更改为 foo:TwoHeadedGridView。不要忘记结束标记。

另一个修改：

您也可以在不创建自定义类的情况下执行此操作。

只需为网格的 DataBound 事件添加一个事件处理程序，如下所示：

protected void gvOrganisms_DataBound(object sender, EventArgs e)

    GridView grid = sender as GridView;

    if (grid != null)
    
        GridViewRow row = new GridViewRow(0, -1,
            DataControlRowType.Header, DataControlRowState.Normal);

        TableCell left = new TableHeaderCell();
        left.ColumnSpan = 3;
        row.Cells.Add(left);

        TableCell totals = new TableHeaderCell();
        totals.ColumnSpan = grid.Columns.Count - 3;
        totals.Text = "Totals";
        row.Cells.Add(totals);

        Table t = grid.Controls[0] as Table;
        if (t != null)
        
            t.Rows.AddAt(0, row);
        
    

自定义控件的优点是您可以在 Web 表单的设计视图上看到额外的标题行。不过，事件处理程序方法要简单一些。

【问题讨论】：

更新后的答案对我有很大帮助，感谢您花时间记录它

这里相同 - 感谢您填写空白

注意 - 我发现我必须添加 row.TableSection = TableRowSection.TableHeader 才能使代码正常工作

【参考方案1】：

我采用了接受的答案方法，但将标题添加到现有的 GridView 而不是自定义继承的 GridView。

绑定 GridView 后，我执行以下操作：

/*Create header row above generated header row*/

//create row    
GridViewRow row = new GridViewRow(0, -1, DataControlRowType.Header, DataControlRowState.Normal);

//spanned cell that will span the columns I don't want to give the additional header 
TableCell left = new TableHeaderCell();
left.ColumnSpan = 6;
row.Cells.Add(left);

//spanned cell that will span the columns i want to give the additional header
TableCell totals = new TableHeaderCell();
totals.ColumnSpan = myGridView.Columns.Count - 3;
totals.Text = "Additional Header";
row.Cells.Add(totals);

//Add the new row to the gridview as the master header row
//A table is the only Control (index[0]) in a GridView
((Table)myGridView.Controls[0]).Rows.AddAt(0, row);

/*fin*/

【参考方案2】：

This article 应该为您指明正确的方向。您可以以编程方式创建行并将其添加到位置 0 的集合中。

【讨论】：

谢谢！我使用该链接提出了解决方案。

【参考方案3】：

在VB.NET中选择使用RowDataBound方法的注意

如果您最终弹出了太多额外的标题行，请添加一个 If 语句，该语句仅在 gridview 的标题行没有任何内容（意味着它是当前被绑定的行）时才继续

 If grid.HeaderRow Is Nothing Then

【参考方案4】：

您必须创建一个扩展 gridview 的类，然后覆盖 CreateRow 方法。

尝试以this 为起点

【参考方案5】：

添加行后添加t.EnableViewState = false;：

Dim t As Table = TryCast(grid.Controls(0), Table)
If t IsNot Nothing Then
    t.Rows.AddAt(0, row)
End If

t.EnableViewState = false;

【参考方案6】：

请参考https://***.com/a/9333714/1060656

我创建了这个解决方案示例

要在本地系统中运行，需要创建 2 个文件（一个用于控件，一个用于 aspx），您可以创建一个项目或 2 个项目。

GridViewPlus ==> 控件类 GridViewPlusCustomHeaderRows ==> 保存自定义标头类的集合 CustomHeaderEventArgs ==> 创建自定义标题行时的事件参数

aspx 文件 ==> 测试程序

public class GridViewPlus : GridView


    public event EventHandler<CustomHeaderEventArgs> CustomHeaderTableCellCreated;

    private GridViewPlusCustomHeaderRows _rows;

    public GridViewPlus() : base ()
    
        _rows = new GridViewPlusCustomHeaderRows();
    

    /// <summary>
    /// Allow Custom Headers
    /// </summary>
    public bool ShowCustomHeader  get; set; 


    [PersistenceMode(PersistenceMode.InnerDefaultProperty)]
    [MergableProperty(false)]
    public GridViewPlusCustomHeaderRows CustomHeaderRows
    
        get return  _rows; 

    

    protected virtual void OnCustomHeaderTableCellCreated(CustomHeaderEventArgs e)
    
        EventHandler<CustomHeaderEventArgs> handler = CustomHeaderTableCellCreated;

        // Event will be null if there are no subscribers
        if (handler != null)
        
            // Use the () operator to raise the event.
            handler(this, e);
        

    

    protected override void OnRowCreated(GridViewRowEventArgs e)
    
        if (ShowCustomHeader && e.Row.RowType == DataControlRowType.Header) return;
        base.OnRowCreated(e);
    


    protected override void PrepareControlHierarchy()
    
        //Do not show the Gridview header if show custom header is ON
        if (ShowCustomHeader) this.ShowHeader = false;


        base.PrepareControlHierarchy();
        //Safety Check
        if (this.Controls.Count == 0)
            return;
        bool controlStyleCreated = this.ControlStyleCreated;
        Table table = (Table)this.Controls[0];

        int j = 0;
        if (CustomHeaderRows ==null )return ;

        foreach (TableRow tr in CustomHeaderRows)
        
            OnCustomHeaderTableCellCreated(new CustomHeaderEventArgs(tr,j));
            table.Rows.AddAt(j, tr);
            tr.ApplyStyle(this.HeaderStyle);
            j++;
        


    


public class GridViewPlusCustomHeaderRows : System.Collections.CollectionBase

    public GridViewPlusCustomHeaderRows()
    
    

    public void Add(TableRow aGridViewCustomRow)
    
        List.Add(aGridViewCustomRow);
    

    public void Remove(int index)
    
        // Check to see if there is a widget at the supplied index.
        if (index > Count - 1 || index < 0)
        // If no widget exists, a messagebox is shown and the operation 
        // is cancelled.
        
            throw (new Exception("Index not valid"));
        
        else
        
            List.RemoveAt(index);
        
    

    public TableRow Item(int Index)
    
        // The appropriate item is retrieved from the List object and
        // explicitly cast to the Widget type, then returned to the 
        // caller.
        return (TableRow)List[Index];
    




public class CustomHeaderEventArgs : EventArgs

    public CustomHeaderEventArgs(TableRow tr ,int RowNumber  )
    
        tRow = tr;
        _rownumber = RowNumber;
    
    private TableRow tRow;
    private int _rownumber = 0;


    public int RowNumber  get  return _rownumber;  

    public TableRow HeaderRow
    
        get  return tRow; 
        set  tRow = value; 
    





public partial class _Default : System.Web.UI.Page

    protected void Page_Load(object sender, EventArgs e)
    
        Example1();
        GridViewExtension1.CustomHeaderTableCellCreated += new EventHandler<CustomHeaderEventArgs>(GridViewExtension1_CustomHeaderTableCellCreated);
    

    void GridViewExtension1_CustomHeaderTableCellCreated(object sender, CustomHeaderEventArgs e)
    
        TableRow tc = (TableRow)e.HeaderRow;

        tc.BackColor = System.Drawing.Color.AliceBlue;
    

    private void Example1()
    
        System.Data.DataTable dtSample = new DataTable();
        DataColumn dc1 = new DataColumn("Column1",typeof(string));
        DataColumn dc2 = new DataColumn("Column2",typeof(string));
        DataColumn dc3 = new DataColumn("Column3",typeof(string));
        DataColumn dc4 = new DataColumn("Column4",typeof(string));
       // DataColumn dc5 = new DataColumn("Column5",typeof(string));
        dtSample.Columns.Add(dc1);
        dtSample.Columns.Add(dc2);
        dtSample.Columns.Add(dc3);
        dtSample.Columns.Add(dc4);
       // dtSample.Columns.Add(dc5);
        dtSample.AcceptChanges();

        for (int i = 0; i < 25; i++)
        
            DataRow dr = dtSample.NewRow();

            for (int j = 0; j < dtSample.Columns.Count; j++)
            
                dr[j] = j;
            
            dtSample.Rows.Add(dr);
        
        dtSample.AcceptChanges();
        //GridViewExtension1.ShowHeader = false;
        GridViewExtension1.ShowCustomHeader = true;

        /*
         *=======================================================================
         *  |Row 1 Cell 1   |   Row 1 Col 2 (Span=2)        | Row 1 Col 3   |
         *  |               |                               |               |
         *=======================================================================             
         *  |Row 2 Cell 1   |               |               |               |
         *  |               |   Row 2 Col 2 | Row 2 Col 3   |Row 2 Col 4    |
         *=======================================================================
         * 
         * 
         * 
         * 
         * */

        // SO we have to make 2 header row as shown above

        TableRow TR1 = new TableRow();
        TableCell tcR1C1 = new TableCell();
        tcR1C1.Text = "Row 1 Cell 1";
        tcR1C1.ColumnSpan = 1;
        TR1.Cells.Add(tcR1C1);       

        TableCell tcR1C2 = new TableCell();
        tcR1C2.Text = "Row 1 Cell 2";
        tcR1C2.ColumnSpan = 2;
        TR1.Cells.Add(tcR1C2);  

        TableCell tcR1C3 = new TableCell();
        tcR1C3.Text = "Row 1 Cell 3";
        tcR1C3.ColumnSpan = 1;
        TR1.Cells.Add(tcR1C3);


        GridViewExtension1.CustomHeaderRows.Add(TR1);

        TableRow TR2 = new TableRow();
        TableCell tcR2C1 = new TableCell();
        tcR2C1.Text = "Row 2 Cell 1";
        tcR2C1.ColumnSpan = 1;
        TR2.Cells.Add(tcR2C1);

        TableCell tcR2C2 = new TableCell();
        tcR2C2.Text = "Row 2 Cell 2";
        tcR2C2.ColumnSpan = 1;
        TR2.Cells.Add(tcR2C2);

        TableCell tcR2C3 = new TableCell();
        tcR2C3.Text = "Row 2 Cell 3";
        tcR2C3.ColumnSpan = 1;
        TR2.Cells.Add(tcR2C3);

        TableCell tcR2C4 = new TableCell();
        tcR2C4.Text = "Row 2 Cell 4";
        tcR2C4.ColumnSpan = 1;
        TR2.Cells.Add(tcR2C4);

        GridViewExtension1.CustomHeaderRows.Add(TR2);


        GridViewExtension1.DataSource = dtSample;
        GridViewExtension1.DataBind();

    

【参考方案7】：

我想做一个类似的任务，但需要标题内的可点击按钮 - 在这种情况下，以上都不起作用，因为事件处理程序没有连接（由于事件的顺序）。最后，我在网格视图的相应模板字段中使用了 headertemplate 标记。 html 看起来有点臃肿，但事件保持不变，无需额外的代码。例如

<asp:TemplateField >
             <HeaderTemplate>
               <div>
                <div style="text-align: center;padding-bottom: 5px;">
                                                          text
                   </div>
                    <div>
                     <asp:Button ID="Button1" runat="server" Text="Apply to all" ToolTip="Apply to all - Special Bolt On" CssClass="sub_button input_btn_5" OnClick="ApplyButton1_Click" />
                   </div>
                  </div>
                  </HeaderTemplate>
                  <ItemTemplate>....