解决SharePoint中GridView导出Excel按钮的问题

大家都知道ASP.NET中GridView导出Excel的方法。在SharePoint中SPGridView是继承GridView的一个扩展控件，那么ASP.NET中的导出方法在SharePoint中也应适用。是可以用，但是有一个问题，就是第一次点击按钮导出成功后，你再次点击按钮的话，按钮就不在有用了。于是Google了一下，找到了这篇Export GridView to Excel in web part帖子解决了问题，就是在Page_Load中注册两行Javascript脚本。
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protected void Page_Load(object sender, EventArgs e)
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{
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this.CreateToolBar();
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string script = "_spOriginalFormAction = document.forms[0].action;\n_spSuppressFormOnSubmitWrapper = true;";
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this.ClientScript.RegisterClientScriptBlock(this.GetType(), "script", script, true);
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}
创建ToolBar方法：
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private void CreateToolBar()
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{
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ToolBar toolBar = (ToolBar)Page.LoadControl("~/_controltemplates/ToolBar.ascx");
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ToolBarButton btnExportToExcel = (ToolBarButton)Page.LoadControl("~/_controltemplates/ToolBarButton.ascx");
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btnExportToExcel.ID = "btnExportToExcel";
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btnExportToExcel.Text = "Export to Spreadsheet";
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btnExportToExcel.ImageUrl = "/_layouts/images/icxls.gif";
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btnExportToExcel.Click += new EventHandler(btnExportToExcel_Click);
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toolBar.Buttons.Controls.Add(btnExportToExcel);
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this.Toolbar.Controls.Clear();
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this.Toolbar.Controls.Add(toolBar);
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}
导出按钮事件：
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void btnExportToExcel_Click(object sender, EventArgs e)
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{
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ExportToExcel("SearchResults", gvSearchResults);
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}
下面是SharePoint中导出Excel的完整代码：
view sourceprint?
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protected void ExportToExcel(string fileName, GridView gv)
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{
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Response.Clear();
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Response.Charset = "GB2312";
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Response.AddHeader("content-disposition", string.Format("attachment; filename={0}", fileName));
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Response.ContentType = "application/ms-excel";
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using (TextWriter tw = new StringWriter())
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{
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using (HtmlTextWriter htw = new HtmlTextWriter(tw))
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{
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Table table = new Table();
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table.GridLines = gv.GridLines;
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if (gv.HeaderRow != null)
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{
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PrepareControlForExport(gv.HeaderRow);
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table.Rows.Add(gv.HeaderRow);
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}
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foreach (GridViewRow row in gv.Rows)
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{
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PrepareControlForExport(row);
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table.Rows.Add(row);
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}
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if (gv.FooterRow != null)
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{
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PrepareControlForExport(gv.FooterRow);
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table.Rows.Add(gv.FooterRow);
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}
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table.RenderControl(htw);
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Response.Write(tw.ToString());
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Response.End();
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}
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}
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}
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private void PrepareControlForExport(Control control)
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{
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for (int i = 0; i < control.Controls.Count; i++)
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{
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Control current = control.Controls[i];
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if (current is LinkButton)
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{
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control.Controls.Remove(current);
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control.Controls.AddAt(i, new LiteralControl((current as LinkButton).Text));
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}
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else if (current is ImageButton)
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{
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control.Controls.Remove(current);
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control.Controls.AddAt(i, new LiteralControl((current as ImageButton).AlternateText));
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}
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else if (current is HyperLink)
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{
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control.Controls.Remove(current);
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control.Controls.AddAt(i, new LiteralControl((current as HyperLink).Text));
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}
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else if (current is DropDownList)
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{
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control.Controls.Remove(current);
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control.Controls.AddAt(i, new LiteralControl((current as DropDownList).SelectedItem.Text));
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}
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else if (current is CheckBox)
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{
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control.Controls.Remove(current);
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control.Controls.AddAt(i, new LiteralControl((current as CheckBox).Checked ? "True" : "False"));
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}
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if (current.HasControls())
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{
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PrepareControlForExport(current);
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}
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}
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}