Question

我写了这个：

protected void btnup_Click(object sender, EventArgs e)
{
    if (ASPxUploadControl1.HasFile)
    {
        try
        {
            string filename = Path.GetFileName(ASPxUploadControl1.FileName);
            ASPxUploadControl1.SaveAs(Server.MapPath("upload/") + filename);
            StatusLabel.Text = "Upload status: File uploaded!";
        }
        catch (Exception ex)
        {
            StatusLabel.Text = "Upload status: The file could not be uploaded. The following error occured: " + ex.Message;
        }
    }
}

问题是，如果我已经有File1.jpg，如果其他人上传File1.jpg，它将覆盖它。

这里做什么？

Answer 1

这里可以做些什么来使文件名在服务器上唯一，以避免覆盖。

if (ASPxUploadControl1.HasFile)
{
    try
    {
        string extension = Path.GetExtension(ASPxUploadControl1.FileName);
        string id = Guid.NewGuid().ToString();
        string fileLocation = string.Format("{0}/{1}{2}", 
                                            Server.MapPath("upload/"), 
                                            id, extension);
        ASPxUploadControl1.SaveAs( fileLocation );
        StatusLabel.Text = "Upload status: File uploaded!";
    }
    catch (Exception ex)
    {
        StatusLabel.Text = "Upload status: The file could not be uploaded. " 
                            + "The following error occured: " + ex.Message;
    }
}

Answer 2

当您致电ASPxUploadControl1.SaveAs时，assign是一个唯一名称。例如，内容的运行编号/ GUID / MD5哈希。无论你认为合适。

我发现使用System.Guid.NewGuid().ToString()

创建新的GUID字符串最简单

Answer 3

您必须为文件名指定unique名称 DB序列或静态运行数变量可能适合您。

您可以使用随机唯一GUID字符串，请参阅this MSDN文章

Answer 4

我建议您在Web应用程序中保存文件时使用Guid以避免此类问题，我通常会使用：

Guid.NewGuid().ToString().Replace("-", "").ToUpper()

表示文件名。

Answer 5

protected void btnup_Click(object sender, EventArgs e)
        {
            if (ASPxUploadControl1.HasFile)
            {
                try
                {
                    string ext = Path.GetExtension(ASPxUploadControl1.FileName);
                    string filename = DateTime.Now.Ticks.ToString()+ext;
                    ASPxUploadControl1.SaveAs(Server.MapPath("upload/") + filename);
                    StatusLabel.Text = "Upload status: File uploaded!";
                }
                catch (Exception ex)
                {
                    StatusLabel.Text = "Upload status: The file could not be uploaded. The following error occured: " + ex.Message;
                }
            }
    }

ASP.net上传文件，如果存在则重命名

5 个答案: