文件名称:图片上传并按比例缩小
文件大小:8KB
文件格式:TXT
更新时间:2012-05-28 07:40:10
图片上传并按比例缩小 在ASP.NET中上传图片并生成缩略图的C#源码 using System; using System.Collections; using System.ComponentModel; using System.Data; using System.Drawing; using System.Web; using System.Web.SessionState; using System.Web.UI; using System.Web.UI.WebControls; using System.Web.UI.HtmlControls; using System.IO; using System.Drawing.Imaging; namespace eMeng.Exam { ///
在ASP.NET里轻松实炙趼酝?lt;/h3>";
Button1.Text = "上载并显示缩略图";
}
#region Web 窗体设计器生成的代码
override protected void OnInit(EventArgs e)
{
//
// CODEGEN: 该调用是 ASP.NET Web 窗体设计器所必需的。
//
InitializeComponent();
base.OnInit(e);
}
///
/// 设计器支持所需的方法 - 不要使用代码编辑器修改
/// 此方法的内容。
///
private void InitializeComponent()
{
this.Button1.Click += new System.EventHandler(this.Button1_Click);
this.Load += new System.EventHandler(this.Page_Load);
}
#endregion
private void Button1_Click(object sender, System.EventArgs e)
{
HttpFileCollection MyFileColl = HttpContext.Current.Request.Files;
HttpPostedFile MyPostedFile = MyFileColl[0];
if (MyPostedFile.ContentType.ToString().ToLower().IndexOf("image") < 0)
{
Response.Write("无效的图形格式。");
return;
}
GetThumbNail(MyPostedFile.FileName, 100, 100,
MyPostedFile.ContentType.ToString(), false, MyPostedFile.InputStream);
}
private System.Drawing.Imaging.ImageFormat GetImageType(object strContentType)
{
if ((strContentType.ToString().ToLower()) == "image/pjpeg")
{
return System.Drawing.Imaging.ImageFormat.Jpeg;
}
else if ((strContentType.ToString().ToLower()) == "image/gif")
{
return System.Drawing.Imaging.ImageFormat.Gif;
}
else if ((strContentType.ToString().ToLower()) == "image/bmp")
{
return System.Drawing.Imaging.ImageFormat.Bmp;
}
else if ((strContentType.ToString().ToLower()) == "image/tiff")
{
return System.Drawing.Imaging.ImageFormat.Tiff;
}
else if ((strContentType.ToString().ToLower()) == "image/x-icon")
{
return System.Drawing.Imaging.ImageFormat.Icon;
}
else if ((strContentType.ToString().ToLower()) == "image/x-png")
{
return System.Drawing.Imaging.ImageFormat.Png;
}
else if ((strContentType.ToString().ToLower()) == "image/x-emf")
{
return System.Drawing.Imaging.ImageFormat.Emf;
}
else if ((strContentType.ToString().ToLower()) == "image/x-exif")
{
return System.Drawing.Imaging.ImageFormat.Exif;
}
else if ((strContentType.ToString().ToLower()) == "image/x-wmf")
{
return System.Drawing.Imaging.ImageFormat.Wmf;
}
else
{
return System.Drawing.Imaging.ImageFormat.MemoryBmp;
}
}
private void GetThumbNail(string strFileName, int iWidth, int iheight,
string strContentType, bool blnGetFromFile, System.IO.Stream ImgStream)
{
System.Drawing.Image oImg;
if (blnGetFromFile)
{
oImg = System.Drawing.Image.FromFile(strFileName);
}
else
{
oImg = System.Drawing.Image.FromStream(ImgStream);
}
oImg = oImg.GetThumbnailImage(iWidth, iheight, null, IntPtr.Zero);
string strGuid = System.Guid.NewGuid().ToString().ToUpper();
string strFileExt = strFileName.Substring(strFileName.LastIndexOf("."));
Response.ContentType = strContentType;
MemoryStream MemStream = new MemoryStream();
oImg.Save(MemStream, GetImageType(strContentType));
MemStream.WriteTo(Response.OutputStream);
}
}
}
功能:
1。把图片文件(JPG GIF PNG)上传,
2。保存到指定的路径(在web.config中设置路径,以文件的原有格式保存),
3。并自动生成指定宽度的(在web.config中设置宽度)
4。和指定格式的(在web.config中指定缩略图的格式)
5。和原图比例相同的缩略图(根据宽度和原图的宽和高计算所略图的高度)
6。可以判断是否已经存在文件
7。如果不覆盖,则给出错误
8。如果选中"覆盖原图"checkbox,则覆盖原图。
9。可以根据要求,在webform上设置1个以上的file input和相应的checkbox
10。并在文件上传完毕后,显示原图的文件名,尺寸,字节,和
11。缩略图的文件名尺寸。
12。缩略图的文件名格式:原图+"_thumb."+指定格式,如:test.jpg_thumb.gif,以便于管理。
--------------------
public void UploadFile(object sender, System.EventArgs e)
{
string imgNameOnly, imgNameNoExt, imgExt;
string imgThumbnail;
int erroNumber = 0;
System.Drawing.Image oriImg, newImg;
string strFePicSavePath = ConfigurationSettings.AppSettings["FePicSavePath"].ToString();
string strFePicThumbFormat = ConfigurationSettings.AppSettings["FePicThumbFormat"].ToString().ToLower();
int intFeThumbWidth = Int32.Parse(ConfigurationSettings.AppSettings["FePicThumbWidth"]);
string fileExt;
StringBuilder picInfo = new StringBuilder();
if(Page.IsValid)
{
for(int i = 0;i < Request.Files.Count; i++)
{
HttpPostedFile PostedFile = Request.Files[i];
fileExt = (System.IO.Path.GetExtension(PostedFile.FileName)).ToString().ToLower();
imgNameOnly = System.IO.Path.GetFileName(PostedFile.FileName);
if(fileExt == ".jpg" || fileExt == ".gif" || fileExt == ".png")
{
if(System.IO.File.Exists(strFePicSavePath + imgNameOnly) && (checkboxlistRewrite.Items[i].Selected == false))
{
erroNumber = erroNumber + 1;
picInfo.Append("错误:文件("+ (i+1) +") " + imgNameOnly + " 已经存在,请修改文件名" ); } } else { erroNumber = erroNumber + 1; picInfo.Append("错误:文件("+ (i+1) +") " + imgNameOnly + " 扩展名 " + fileExt + " 不被许可
" ); } } if(erroNumber > 0) { picInfo.Append("全部操作均未完成,请修改错误,再进行操作
"); } else { for(int i = 0;i < Request.Files.Count; i++) { HttpPostedFile PostedFile = Request.Files[i]; imgNameOnly = System.IO.Path.GetFileName(PostedFile.FileName); imgNameNoExt = System.IO.Path.GetFileNameWithoutExtension(PostedFile.FileName); imgExt = System.IO.Path.GetExtension(PostedFile.FileName).ToString().ToLower(); oriImg = System.Drawing.Image.FromStream(PostedFile.InputStream); newImg = oriImg.GetThumbnailImage(intFeThumbWidth, intFeThumbWidth * oriImg.Height/oriImg.Width,null,new System.IntPtr(0)); switch(imgExt) { //case ".jpeg": case ".jpg": oriImg.Save(strFePicSavePath + imgNameOnly , System.Drawing.Imaging.ImageFormat.Jpeg); break; case ".gif": oriImg.Save(strFePicSavePath + imgNameOnly , System.Drawing.Imaging.ImageFormat.Gif); break; case ".png": oriImg.Save(strFePicSavePath + imgNameOnly , System.Drawing.Imaging.ImageFormat.Png); break; } //oriImg.Save(ConfigurationSettings.AppSettings["FePicSavePath"] + imgNameNoExt + ".jpg", System.Drawing.Imaging.ImageFormat.Jpeg); switch(strFePicThumbFormat) { //jpeg format can get the smallest file size, and the png is the largest size //case "jpeg": case "jpg": newImg.Save(strFePicSavePath + imgNameOnly + "_thumb.jpg",System.Drawing.Imaging.ImageFormat.Jpeg); imgThumbnail = imgNameOnly + "_thumb.jpg"; break; case "gif": newImg.Save(strFePicSavePath + imgNameOnly + "_thumb.gif",System.Drawing.Imaging.ImageFormat.Gif); imgThumbnail = imgNameOnly + "_thumb.gif"; break; case "png": newImg.Save(strFePicSavePath + imgNameOnly + "_thumb.png",System.Drawing.Imaging.ImageFormat.Png); imgThumbnail = imgNameOnly + "_thumb.png"; break; default: newImg.Save(strFePicSavePath + imgNameOnly + "_thumb.jpg",System.Drawing.Imaging.ImageFormat.Jpeg); imgThumbnail = imgNameOnly + "_thumb.jpg"; break; }//switch picInfo.Append("文件 名:" + imgNameOnly + " ( " + oriImg.Width + " x " + oriImg.Height + " ) " + PostedFile.ContentLength/1024 + "KB
"); picInfo.Append("缩略图名:" + imgThumbnail + " ( " + newImg.Width + " x " + newImg.Height + " )
"); oriImg.Dispose(); newImg.Dispose(); }//for picInfo.Append("所有操作成功
"); }// if erronumber = 0 } else { picInfo.Append("有错误,请检查。操作未成功
"); } lblPicInfo.Text = picInfo.ToString(); } 资料引用:http://www.knowsky.com/5723.html