string uploadName = InputFile.FileName;//获取待上传图片的完整路径，包括文件名
string pictureName = "";//上传后的图片名，以当前时间为文件名，确保文件名没有重复 
if (InputFile.HasFile)
{
    int idx = uploadName.LastIndexOf(".");
    string suffix = uploadName.Substring(idx);//获得上传的图片的后缀名 
    pictureName = DateTime.Now.Ticks.ToString() + suffix;
}
try
{
    if (InputFile.HasFile)
    {
        string path = Server.MapPath("~/images/");
        InputFile.PostedFile.SaveAs(path + pictureName);
    }
}
catch (Exception ex)
{
    Response.Write(ex.Message);
}