向ASP.NET Gridview添加动态列

我在GridView中动态添加列时遇到问题.我需要根据DropDownList中的值来更改布局(即包含的列).当用户更改此列表中的选择时,我需要删除除第一列之外的所有内容,并根据选择动态添加其他列.

我的标记中只有一列 – 列0,一个模板列,其中我声明一个选择链接和另一个应用程序特定的LinkButton.那个列需要永远在那里.当创建ListBoxSelection时,我删除除第一列之外的所有列,然后重新添加所需的列(在此示例中,我简化了它以始终添加“标题”列).以下是代码的一部分：

RemoveVariableColumnsFromGrid();
BoundField b = new BoundField();
b.datafield = "Title";
this.gvPrimaryListView.Columns.Add(b);
this.gvPrimaryListView.DataBind();


private void RemoveVariableColumnsFromGrid() {
    int ColCount = this.gvPrimaryListView.Columns.Count;
    //Leave column 0 -- our select and view template column
    while (ColCount > 1) {
        this.gvPrimaryListView.Columns.RemoveAt(ColCount - 1);
        --ColCount;
    }
}

该代码第一次运行时,我看到静态列和动态添加的“标题”列.但是,下一次进行选择时,第一列生成为空(其中没有内容).我看到标题列,我看到左边的第一列 – 但是内部没有任何内容.在调试器中,我可以看到gvPrimaryListView确实还有两列,第一列(索引0)确实是一个模板列.实际上,列甚至保留了下面标记中设置为165px的宽度(用于调试目的).

有任何想法吗？

<asp:GridView ID="gvPrimaryListView" runat="server" Width="100%" AutoGenerateColumns="false"
    DataKeyNames="Document_ID" EnableViewState="true" DataSourceID="odsPrimaryDataSource"
    AllowPaging="true" AllowSorting="true" PageSize="10" OnPageIndexChanging="activeListView_PageIndexChanging"
    AutoGenerateSelectButton="False" OnSelectedindexChanged="activeListView_SelectedindexChanged"
    Visible="true" OnRowDataBound="CtlDocList_RowDataBound" Font-Size="8pt" Font-Names="Helvetica">
    <Columns>
        <asp:TemplateField ShowHeader="false">
            <ItemTemplate>
                <asp:LinkButton EnableTheming="false" ID="CtlSelectDocRowBtn" runat="server" Text="Select"
                    CommandName="Select" CssClass="gridbutton" OnClick="RowSelectBtn_Click" />
                <asp:ImageButton EnableTheming="false" ID="DocViewBtn" runat="server" ImageUrl="../../images/ViewDoc3.png"
                    CssClass="gridbutton" CommandName="Select" OnClick="DocViewBtn_Click" />
            </ItemTemplate>
            <ItemStyle Width="165px" />
        </asp:TemplateField>
    </Columns>
    <EmptyDataTemplate>
        <asp:Label ID="Label6" runat="server" Text="No rows found." SkinID="LabelHeader"></asp:Label>
    </EmptyDataTemplate>
</asp:GridView>

只是一些额外的信息.

它与第一列无关,但它与TemplateField的事实有关.如果我将一个普通的列放在左边(在标记中),并且将TemplateField列移到右边,那么第一列渲染得很好,(现在第二个)TemplateField列消失.

另一个奇怪的事情 – 问题不会发生在第一次回发 – 或第二 – 但它开始于第三个回发,然后继续后续的回发.我被困了

解决方法

我最近在网格视图中征服了动态列的类似问题,也许这将有所帮助.

首先关闭viewstate
第二,在oninit事件触发的函数中以列表方式添加列
最后,我使用以下帮助器类来使得复选框在RowDataBound事件启动时实例化.是的,有些是硬编码.

这里是所有的代码.有在这里:) Warrenty as is,blah blah blah …

最后,因为我刚刚得到我的脚湿DotNet任何提示将不胜感激[IE不要撕我太多:)].是的,“借用”网站上的初始代码,对不起,我不记得我的头顶

– 在受保护的覆盖范围内将其释放掉OnInit

private void GridViewProject_AddColumns()
    {
        DataSet dsDataSet = new DataSet();
        TemplateField templateField = null;

        try
        {
            StoredProcedure sp = new StoredProcedure("ExpenseReportItemType_GetList","INTRANETWEBDB",Context.User.Identity.Name);
            dsDataSet = sp.GetDataSet();

            if (sp.RC != 0 && sp.RC != 3000)
            {
                labelMessage.Text = sp.ErrorMessage;
            }

            int iIndex = 0;
            int iCount = dsDataSet.Tables[0].Rows.Count;
            string strCategoryID = "";
            string strCategoryName = "";
            iStaticColumnCount = GridViewProject.Columns.Count;

            // Insert all columns immediatly to the left of the LAST column
            while (iIndex < iCount)
            {
                strCategoryName = dsDataSet.Tables[0].Rows[iIndex]["CategoryName"].ToString();
                strCategoryID = dsDataSet.Tables[0].Rows[iIndex]["CategoryID"].ToString();

                templateField = new TemplateField();
                templateField.HeaderTemplate = new GridViewTemplateExternal(DataControlRowType.Header,strCategoryName,strCategoryID);
                templateField.ItemTemplate = new GridViewTemplateExternal(DataControlRowType.DaTarow,strCategoryID);
                templateField.FooterTemplate = new GridViewTemplateExternal(DataControlRowType.Footer,strCategoryID);

                // Have to decriment iStaticColumnCount to insert dynamic columns BEFORE the edit row
                GridViewProject.Columns.Insert((iIndex + (iStaticColumnCount-1)),templateField);
                iIndex++;
            }
            iFinalColumnCount = GridViewProject.Columns.Count;
            iERPEditColumnIndex = (iFinalColumnCount - 1); // iIndex is zero based,Count is not
        }
        catch (Exception exception)
        {
            labelMessage.Text = exception.Message;
        }
    }

– 助手班

public class GridViewTemplateExternal : System.Web.UI.ITemplate
{
    #region Fields
    public DataControlRowType DaTarowType;
    private string strCategoryID;
    private string strColumnName;
    #endregion

    #region Constructor
    public GridViewTemplateExternal(DataControlRowType type,string ColumnName,string CategoryID)
    {
        DaTarowType = type; // Header,DaTarow,strColumnName = ColumnName; // Header name
        strCategoryID = CategoryID;
    }
    #endregion

    #region Methods
    public void InstantiateIn(System.Web.UI.Control container)
    {
        switch (DaTarowType)
        {
            case DataControlRowType.Header:
                // build the header for this column
                Label labelHeader = new Label();
                labelHeader.Text = "<b>" + strColumnName + "</b>";
                // All CheckBoxes "Look Up" to the header row for this information
                labelHeader.Attributes["ERICategoryID"] = strCategoryID;
                labelHeader.Style["writing-mode"] = "tb-rl";
                labelHeader.Style["filter"] = "flipv fliph";
                container.Controls.Add(labelHeader);
                break;
            case DataControlRowType.DaTarow:
                CheckBox checkBoxAllowedRow = new CheckBox();
                checkBoxAllowedRow.Enabled = false;
                checkBoxAllowedRow.DataBinding += new EventHandler(this.CheckBox_DataBinding);
                container.Controls.Add(checkBoxAllowedRow);
                break;
            case DataControlRowType.Footer:
                // No data handling for the footer addition row
                CheckBox checkBoxAllowedFooter = new CheckBox();
                container.Controls.Add(checkBoxAllowedFooter);
                break;
            default:
                break;
        }
    }
    public void CheckBox_DataBinding(Object sender,EventArgs e)
    {
        CheckBox checkBoxAllowed = (CheckBox)sender;// get the control that raised this event
        GridViewRow row = (GridViewRow)checkBoxAllowed.NamingContainer;// get the containing row
        string RawValue = DataBinder.Eval(row.DataItem,strColumnName).ToString();
        if (RawValue.toupper() == "TRUE")
        {
            checkBoxAllowed.Checked = true;
        }
        else
        {
            checkBoxAllowed.Checked = false;
        }
    }
    #endregion
}

原文地址：https://www.jb51.cc/aspnet/250533.html

向ASP.NET Gridview添加动态列

解决方法

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