向ASP.NET Gridview添加动态列

我最近克服了GridView中动态列的类似问题,也许这会有所帮助。

首先关闭viewstate

最后,我使用以下帮助器类在RowDataBound事件启动时使复选框实例化。是的,有些是硬编码的。

见鬼,这是所有的代码。试试看:)沃伦蒂就这样,胡说八道。。。

最后,由于我刚刚在互联网上获得成功,任何提示都将不胜感激。是的,从网上某处“借用”了最初的代码,对不起,我记不得了:(

--在受保护的override void OnInit中将其关闭

    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, strCategoryName, strCategoryID);
                templateField.FooterTemplate = new GridViewTemplateExternal(DataControlRowType.Footer, strCategoryName, 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;
        }
    }

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
}

通过以下地址将动态列添加到放置在代码项目上的网格视图(ASP)的最佳解决方案: 请查看: http://www.codeproject.com/Articles/13461/how-to-create-columns-dynamically-in-a-grid-view

问题是每次回发时都必须重新绑定网格,因此必须重新生成列。我希望有一个名为BindGrid()的方法,它首先清除列GridView1.Columns.Clear();然后以编程方式添加它们,然后设置数据源并调用databind。确保已禁用网格的viewstate,并且autogeneratecolumns=false;

我今天早些时候发现: TemplateField in a GridView doesn't have its ViewState restored when BoundFields are inserted .

看起来像是一个微软不打算修复的bug,所以你必须尝试上面的一个解决方案。我也遇到了同样的问题——我有一些DataBoundFields和一些TemplateFields,在回发之后,基于TemplateField的列将失去它们的控件和数据。

How to generate GridView columns dynamically based on user selection? .

    void Page_PreRenderComplete(object sender, EventArgs e)
    {
        // TemplateField reorder bug: if there is a TemplateField based column (or derived therefrom), GridView may blank out
        // the column (plus possibly others) during any postback, if the user has moved it from its original markup position.
        // This is probably a viewstate bug, as it happens only if a TemplateField based column has been moved.  The workaround is
        // to force a databind before each response. See https://connect.microsoft.com/VisualStudio/feedback/details/104994/templatefield-in-a-gridview-doesnt-have-its-viewstate-restored-when-boundfields-are-inserted
        //
        // This problem is also happening for grid views inside a TabPanel, even if the TemplateField based columns have not
        // been moved.  Also do a databind in that case.
        //
        // We also force a databind right after the user has submitted the column chooser dialog.
        // (This is because the user could have moved TemplateField based column(s) but ColChooserHasMovedTemplateFields()
        // returns false -- ie when the user has moved all TemplateField based columns back to their original positions.
        if ((!_DataBindingDone && (ColChooserHasMovedTemplateFields() || _InTabPanel)) || _ColChooserPanelSubmitted || _ColChooserPanelCancelled)
            DataBind();

        // There is a problem with the GridView in case of custom paging (which is true here) that if we are on the last page,
        // and we delete all row(s) of that page, GridView is not aware of the deletion during the subsequent data binding,
        // will ask the ODS for the last page of data, and will display a blank.  By PreRenderComplete, it will somehow have
        // realized that its PageIndex, PageCount, etc. are too big and updated them properly, but this is too late
        // as the data binding has already occurred with oudated page variables.  So, if we were on the last page just before
        // the last data binding (_LastPageIndex == _LastPageCount - 1) and PageIndex was decremented after the data binding,
        // we know this scenario has happened and we redo the data binding.  See http://scottonwriting.net/sowblog/archive/2006/05/30/163173.aspx
        // for a discussion of the problem when the GridView uses the ODS to delete data.  The discussion also applies when we
        // delete data directly through ClassBuilder objects.
        if (_LastPageIndex == _LastPageCount - 1 && PageIndex < _LastPageIndex)
            DataBind();

        if (EnableColChooser)
        {
            if (!_IsColChooserApplied)
                ApplyColChooser(null, false, false);
            else
            {
                // The purpose of calling ApplyColChooser() here is to order the column headers properly.  The GridView
                // at this point will have reverted the column headers to their original order regardless of ViewState,
                // so we need to apply our own ordering.  (This is not true of data cells, so we don't have to apply
                // ordering to them, as reflected by the parameters of the call.)

                // If we have already processed column reordering upon the column chooser panel being submitted,
                // don't repeat the operation.
                if (!_ColChooserPanelSubmitted)
                    ApplyColChooser(null, false, true);
            }
        }
    }

如果您使用的是GridView或DetailsView控件,则自动创建的DataControlField对象(例如,当AutoGenerateColumns属性为true时)不会存储在可公开访问的fields集合中。您只能访问和操作未自动生成的DataControlField对象。

我想答案是在代码中完成所有列操作,然后您的方法应该可以很好地工作。

您是否可以在开始时定义列,并根据需要隐藏/显示它们(使用Visible=“false”或将控件/页眉/页脚的CssClass设置为使用“display:none;”的类,而不是动态添加列?我在一些代码中使用此方法,包括模板列,没有任何问题。

对不起,戴克。我显然遗漏了几个关键点:)

如果这对您来说仍然是一个问题,我想知道这是否会对您在项目模板中的内容产生影响?如果你只是把一些文本放在那里,然后刷新页面几次,文本是在第一次加载时出现的,而不是在第二次加载时出现的吗?