同时使用File复制文件.复制我得到错误

当我运行文件。对于大文件，我得到以下错误，但在后端文件被复制了两次。

无法访问此站点http://*******************的网页可能暂时关闭或已永久移动到新网址。ERR_INVALID_HANDLE

foreach (GridViewRow row in grdAppDetails.Rows)
{
    Label lblPublishPath = (Label)row.FindControl("lblPublishPath");
    Label lblBackupPath = (Label)row.FindControl("lblBackupPath");
    string BackupPath = lblBackupPath.Text + "''" + drpApplication.SelectedValue.ToString() + "_" + DateTime.Now.ToString("yyyyMMdd");
    DirectoryCopy(lblPublishPath.Text, BackupPath, true);
    DirectoryCopy(txtFolderUpload.Text, lblPublishPath.Text, true);
    deploymentdata.AddAppLogDetails(drpApplication.SelectedValue.ToString(), drpEnv.SelectedValue.ToString(), lblUserName.Text, DateTime.Now, txtFolderUpload.Text, BackupPath, lblPublishPath.Text, txtComments.Text, filenames);
}