C# 如何下载已上载的图像？
我有一个页面，其中有一个C# 如何下载已上载的图像？,c#,asp.net,image,download,C#,Asp.net,Image,Download,我有一个页面，其中有一个asp:fileupload，当图片上传时，它将被存储到一个图像文件夹中。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。然而，我的问题是，我想下载上传的图像时点击。我搜索过谷歌，但我的问题没有答案。希望你能帮助我。以下是我在grid view部分的代码，它从中获取所有上传的图像： protected void Page_Load(object sender, EventArgs e) { if (!Page.IsPos
asp:fileuploadprotected 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();
}
公共类MyNameTransfom:ICSharpCode.SharpZipLib.Core.INameTransform
{
#大城市区域成员
公共字符串目录（字符串名称）
{
返回null；
}
公共字符串文件（字符串名称）
{
返回Path.GetFileName（名称）；
}
#端区
}
公共部分类Default1:System.Web.UI.Page
{
受保护的无效页面加载（对象发送方、事件参数e）
{
ZipFileByCode（）；
}
///
/// 压缩打包文件
///
公共无效ZipFileByCode（）
{
MemoryStream ms=新的MemoryStream（）；
字节[]缓冲区=空；
使用（ZipFile file=ZipFile.Create（ms））
{
BeginUpdate（）文件；
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拉链中创建有关的文件夹。
Add（Server.MapPath（“/Content/images/img01.jpg”）；
Add（Server.MapPath（“/Content/images/img02.jpg”）；
file.CommitUpdate（）；
缓冲区=新字节[ms.Length]；
ms.Position=0；
ms.Read（缓冲区，0，缓冲区长度）；
}
AddHeader（“内容处置”、“附件；文件名=test.zip”）；
二进制写入（缓冲区）；
Response.Flush（）；
Response.End（）；
}
}
您需要下载dll
ICSharpCode.SharpZipLibProcessRequest（）//我已将
ContentType“应用程序/八位字节流”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。我在gridview中使用了链接按钮，有很多方法可以做到这一点。这是我的密码
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;
}
}
因为图像的MIME类型可以用IIS来解释，所以我认为您可能需要将图像文件添加到zip文件中，然后下载zip文件，当然，这些操作必须自动完成。我如何才能做到这一点。此文件allready包含如下所示的ProcessRequest（）public void ProcessRequest（HttpContext上下文）如何获取处理程序？无法搜索有关此的教程。对不起，我是新来的@Kiran Bhagat右键单击项目并添加新项目选择通用处理程序
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;
}
}