解决gridview导出到excel中汉字出现乱码的问题

//导出乱码

protected void Button2_Click(object sender, EventArgs e)
{
GridView1.Focus();
Response.Clear();
Response.Buffer = false;
Response.Charset = "GB2312";
Response.AppendHeader("Content-Disposition", "attachment;filename=pickmorv.xls");
Response.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");
Response.ContentType = "application/ms-excel";
this.EnableViewState = false;
System.IO.StringWriter oStringWriter = new System.IO.StringWriter();
HtmlTextWriter oHtmlTextWriter = new HtmlTextWriter(oStringWriter);
GridView1.RenderControl(oHtmlTextWriter);
Response.Write(oStringWriter.ToString());
Response.End();
}

//导出正常

protected void Button3_Click(object sender, EventArgs e)
{
Response.Clear();
Response.Buffer = false;
Response.Charset = "GB2312";
Response.AppendHeader("Content-Disposition", "attachment;filename=pkmv_de.xls");
Response.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");
Response.ContentType = "application/ms-excel";
Response.Write("<meta http-equiv=Content-Type content=/"text/html; charset=GB2312/">");
this.EnableViewState = false;
System.IO.StringWriter oStringWriter = new System.IO.StringWriter();
HtmlTextWriter oHtmlTextWriter = new HtmlTextWriter(oStringWriter);
GridView2.RenderControl(oHtmlTextWriter);
Response.Write(oStringWriter.ToString());
Response.End();
}