asp.net 导出excel 表之后 按钮 页面控件失效不可用，没反应的解决办法。

页面导出excel 后无奈的面对了另一个问题

就是导出excel 表之后 页面上的所有按钮 点击都没有反应,需要重新载入

在页面导出excel代码如下:

public void DataTableToExcel(DataTable dt,string filename)
        {
            if (dt != null & dt.Rows.Count > 0)
            {
                Response.Clear();
                Response.Buffer = true;
                //Response.Charset = "utf-8";
                Response.ContentEncoding = System.Text.Encoding.Default;
                Response.AppendHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(filename, Encoding.Default).ToString());
                Response.ContentType = "application/vnd.ms-excel";
                this.EnableViewState = false;
                StringWriter oStringWriter = new StringWriter();
                HtmlTextWriter oHtmlTextWriter = new HtmlTextWriter(oStringWriter);
                Response.Write(style);
                DataGrid ExcelDG = new DataGrid();

                ExcelDG.DataSource = dt; 
                ExcelDG.DataBind();
                ExcelDG.RenderControl(oHtmlTextWriter);
                Response.Write(oStringWriter.ToString());
                Response.End();
            }
        }

刚开始 我以为是response的 表头属性的缘故  或者是 response.Write 这个方法的问题

几经搜索，发现 是由于 response.end() 的缘故   

所有 只需要写一个方法 refresh（）放到 page_load 里 问题就解决了。

VB.NET    这个是根据C#的代码改写的 使用了 StringBuilder 。

sub refresh（）

       Dim beforeSubmitJS As StringBuilder = New StringBuilder()

        beforeSubmitJS.Append("var exportRequested = false;" & vbCrLf)
        beforeSubmitJS.Append("var beforeFormSubmitFunction = theForm.onsubmit;" & vbCrLf)
        beforeSubmitJS.Append("theForm.onsubmit = function(){ " & vbCrLf)
        beforeSubmitJS.Append("var returnVal = beforeFormSubmitFunction();" & vbCrLf)
        beforeSubmitJS.Append("if(exportRequested && returnVal) {_spFormOnSubmitCalled=false; exportRequested=false;}" & vbCrLf)
        beforeSubmitJS.Append("return returnVal;" & vbCrLf)
        beforeSubmitJS.Append("}; " & vbCrLf)

        Me.Page.ClientScript.RegisterStartupScript(Me.GetType(), "alterFormSubmitEvent", beforeSubmitJS.ToString(), True)

        Me.btnClose.Attributes("onclick") = "javascript:exportRequested=true;"
        Me.btnSave2Excel.Attributes("onclick") = "javascript:exportRequested=true;"
        Me.btnSelect.Attributes("onclick") = "javascript:exportRequested=true;"

end sub

C#

public void refresh(Button btn)
{
string beforeSubmitJS = "\nvar exportRequested = false; \n";
beforeSubmitJS += "var beforeFormSubmitFunction = theForm.onsubmit;\n";
beforeSubmitJS += "theForm.onsubmit = function(){ \n";
beforeSubmitJS += "var returnVal = beforeFormSubmitFunction(); \n";
beforeSubmitJS += "if(exportRequested && returnVal) {_spFormOnSubmitCalled=false; exportRequested=false;} \n";
beforeSubmitJS += "return returnVal; \n";
beforeSubmitJS += "}; \n";
this.Page.ClientScript.RegisterStartupScript(this.GetType(), "alterFormSubmitEvent", beforeSubmitJS, true);
btn.Attributes["onclick"] = "javascript:exportRequested=true;";
}

调用例如下：

protected void Page_Load(object sender, EventArgs e)
{
refresh(btnExport);//这里改成你的按钮的名字即可

}

 原理：页面按钮提交时会调用一个内置的方法并修改一个内置变量_spFormOnSubmitCalled，我们通过按钮来调用方法重置

这个参数的值，达到系统检索页面时，一直默认为未提交状态。