Question

我有一个页面，其中有一个asp:fileupload，然后当图片上传时，它将被存储到图像文件夹中。我还制作了另一个网页，它有一个gridview，可以从目标文件夹中获取图像。但是我的问题是我想在点击时下载上传的图像。我搜索过谷歌，但我的查询没有答案。希望您能够帮助我。这是我在网格视图部分的代码，它获取所有上传的图像：

protected void Page_Load(object sender, EventArgs e)
    {
        if (!Page.IsPostBack)
        {

            binddepositslipgrid();

        }
    }
    public void binddepositslipgrid()
    {
        SqlConnection conn = new SqlConnection("Data Source = 'PAULO'; Initial Catalog=ShoppingCartDB;Integrated Security =True");
        SqlCommand cmd = new SqlCommand("select DepositID, Image from DepositSlip ", conn);

        SqlDataAdapter da = new SqlDataAdapter("", conn);
        da.SelectCommand = new SqlCommand("select DepositID, Image from DepositSlip", conn);
        DataSet ds = new DataSet();
        da.Fill(ds, "data");
        gvDeposit.DataSource = ds.Tables[0].DefaultView;
        gvDeposit.DataBind();


    }
    protected void gvDeposit_RowDeleting(object sender, GridViewDeleteEventArgs e)
    {

        int catid = int.Parse(gvDeposit.DataKeys[e.RowIndex].Value.ToString());
        SqlConnection conn = new SqlConnection("Data Source = 'PAULO'; Initial Catalog=ShoppingCartDB;Integrated Security =True");
        SqlDataAdapter da = new SqlDataAdapter("", conn);
        conn.Open();
        da.DeleteCommand = new SqlCommand("delete from DepositSlip where DepositID=" + catid, conn);
        da.DeleteCommand.ExecuteNonQuery();
        conn.Close();
        binddepositslipgrid();
    }

Answer 1

public class MyNameTransfom : ICSharpCode.SharpZipLib.Core.INameTransform
    {

        #region INameTransform 成员

        public string TransformDirectory(string name)
        {
            return null;
        }

        public string TransformFile(string name)
        {
            return Path.GetFileName(name);
        }

        #endregion
    }

    public partial class Default1 : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            ZipFileByCode();
        }

        /// <summary>
        /// 压缩打包文件
        /// </summary>
        public void ZipFileByCode()
        {
            MemoryStream ms = new MemoryStream();
            byte[] buffer = null;

            using (ZipFile file = ZipFile.Create(ms))
            {
                file.BeginUpdate();
                file.NameTransform = new MyNameTransfom();//通过这个名称格式化器，可以将里面的文件名进行一些处理。默认情况下，会自动根据文件的路径在zip中创建有关的文件夹。

                file.Add(Server.MapPath("/Content/images/img01.jpg"));
                file.Add(Server.MapPath("/Content/images/img02.jpg"));
                file.CommitUpdate();

                buffer = new byte[ms.Length];
                ms.Position = 0;
                ms.Read(buffer, 0, buffer.Length);
            }
            Response.AddHeader("content-disposition", "attachment;filename=test.zip");
            Response.BinaryWrite(buffer);
            Response.Flush();
            Response.End();
        }
    }

您需要下载dll ICSharpCode.SharpZipLib

Answer 2

您必须为此操作编写处理程序，并在ProcessRequest()方法中编写用于下载文件的代码

//我已将ContentType设置为"application/octet-stream"，涵盖任何类型的文件

context.Response.ContentType = "application/octet-stream";

                    // context.Response.AddHeader("content-disposition", "attachment;filename=abc.jpg" + Path.GetFileName(file));
                    context.Response.AddHeader("content-disposition", "attachment;filename=" + fileName);

                    //context.Response.w(file);
                    context.Response.OutputStream.Write(data, 0, data.Length);

                    //you can also implement other business request such as delete the file after download
                    context.Response.End();

使用上面的代码，您可以下载图像。

Answer 3

有很多方法可以通过gridview中的链接按钮完成。这是我的代码。

   protected void gvDetails_RowCommand(object sender, System.Web.UI.WebControls.GridViewCommandEventArgs e)
    {
        try
        {
            GridViewRow row = (GridViewRow)((LinkButton)e.CommandSource).NamingContainer;
            Int32 RowIndex = row.RowIndex;
            DataTable dtable = new DataTable();
            dynamic di = new DirectoryInfo(FinalPath+"\\");
            dtable.Columns.Add("DownloadLink", typeof(string));
            dtable.Columns.Add("FileName", typeof(string));
            DataRow dr = null;
            foreach (FileInfo fi in di.GetFiles())
            {
                dr = dtable.NewRow();
                dr["FileName"] = fi.Name;
                dr["DownloadLink"] = FinalPath+"\\" + fi.Name;
                dtable.Rows.Add(dr);
            }
            int i = row.RowIndex;
            string filename = null;
            filename = dtable.Rows[i]["FileName"].ToString();
            string path__1 = (FinalPath + filename);
            string name = dtable.Rows[i]["FileName"] .ToString();
            string last = name.Substring(name.LastIndexOf('.'));
            string ext = last;
            string type = "";
            if (ext != null)
            {
                switch (ext.ToLower())
                {
                    case ".html":
                        {
                            type = "text/HTML";
                            break;
                        }

                    case ".txt":
                        {
                            type = "text/plain";
                            break;
                        }

                    case ".GIF":
                        {
                            type = "image/GIF";
                            break;
                        }

                    case ".pdf":
                        {
                            type = "Application/pdf";
                            break;
                        }

                    case ".doc":
                        {
                            type = "Application/doc";
                            break;
                        }
                    case ".rtf":
                        {
                            type = "Application/msword";
                            break; 
                        }

                    default:
                        {
                            type = "";
                            break; 
                        }

                }
            }
            Response.AppendHeader("content-disposition", "attachment; filename=" + name);
            if (!string.IsNullOrEmpty(type))
            {
                Response.ContentType = type;
            }
            Response.WriteFile(path__1);
            Response.End();
        }
        catch
        {
            ScriptManager.RegisterClientScriptBlock(this.Page, this.GetType(), "myscript", "alert('Something Went Wrong!');", true);
            return;
        }
}

单击链接按钮时将下载图像。它会像这样。

enter image description here

如何下载我上传的图片？

3 个答案: