上传图片生成缩略图
#region 上传图片
EntryInfoF entryInfoF = new EntryInfoF();
EntryInfo entryInfo = entryInfoF.GetEntryInfo(this.EntryId);
HttpPostedFile postFile1 = System.Web.HttpContext.Current.Request.Files["post1"];
if(postFile1.FileName == "")
{
this.Alert("请提供图片文件！");
return;
}
string strPostFileName = System.IO.Path.GetFileName(postFile1.FileName);
string strFilePath = entryInfo.PhysicalPath + "\\" + "Picture\\";
string strSaveFileUrlL = "";
string strSaveFileUrlS = "";
string strSaveFileName = System.DateTime.Now.ToString("yyyy-MM-dd HH.mm ss") + " " + strPostFileName;
if(!System.IO.Directory.Exists(strFilePath))
System.IO.Directory.CreateDirectory(strFilePath);
postFile1.SaveAs(strFilePath + strSaveFileName);
#region 检查图片规格
System.Drawing.Image image = System.Drawing.Image.FromFile(strFilePath + strSaveFileName);
int iWidth = image.Width;
int iHeight = image.Height;
image.Dispose();
bool bIsValid = true;
if((iWidth != 800) | (iHeight != 600))
bIsValid = false;
if(bIsValid != true)
{
this.Alert("图片规格错误！(800*600)");
try
{
System.IO.File.Delete(strFilePath + strSaveFileName);
}
catch{}
return ;
}
#endregion
//缩略图
this.ToThumbnailImages(strFilePath + strSaveFileName,strFilePath + "s" + strSaveFileName,98);
//图片文件Url地址
strSaveFileUrlL = entryInfo.Url + "/" + "Picture" + "/" + strSaveFileName;
strSaveFileUrlS = entryInfo.Url + "/" + "Picture" + "/s" + strSaveFileName;
interfacePicInfo.lUrl = strSaveFileUrlL;
interfacePicInfo.sUrl = strSaveFileUrlS;
// this.lab_logo.Text = string.Format("<a href='{0}' target=_blank>{1}</a>",strSaveFileUrlL,strSaveFileUrlL);
// if(strLogo != "")
// {
// //删除原图片
// string strLLogo = strFilePath + System.IO.Path.GetFileName(GetmagazineInfo.LLogoPath);
// string strsLogo = strFilePath + System.IO.Path.GetFileName(GetmagazineInfo.SLogoPath);
// try
// {
// System.IO.File.Delete(strLLogo);
// System.IO.File.Delete(strsLogo);
// }
// catch{}
// }
#endregion
//生成缩略图ToThumbnailImage.cs文件
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.Drawing.Imaging;
namespace DM100Professional.Base
{
/// <summary>
/// ToThumbnailImage 的摘要说明。
/// </summary>
public class ToThumbnailImage :DM100Professional.Base.PageBase
{
static Hashtable htmimes = new Hashtable();
internal readonly string AllowExt = ".jpe|.jpeg|.jpg|.png|.tif|.tiff|.bmp";
#region Web 窗体设计器生成的代码
override protected void OnInit(EventArgs e)
{
#region
htmimes[".jpe"]="image/jpeg";
htmimes[".jpeg"]="image/jpeg";
htmimes[".jpg"]="image/jpeg";
htmimes[".png"]="image/png";
htmimes[".tif"]="image/tiff";
htmimes[".tiff"]="image/tiff";
htmimes[".bmp"]="image/bmp";
#endregion
}
#endregion
#region Helper
/// <summary>
/// 获取图像编码解码器的所有相关信息
/// </summary>
/// <param name="mimeType">包含编码解码器的多用途网际邮件扩充协议 (MIME) 类型的字符串</param>
/// <returns>返回图像编码解码器的所有相关信息</returns>
static ImageCodecInfo GetCodecInfo(string mimeType)
{
ImageCodecInfo[] CodecInfo = ImageCodecInfo.GetImageEncoders();
foreach(ImageCodecInfo ici in CodecInfo)
{
if(ici.MimeType == mimeType)return ici;
}
return null;
}
/// <summary>
/// 检测扩展名的有效性
/// </summary>
/// <param name="sExt">文件名扩展名</param>
/// <returns>如果扩展名有效,返回true,否则返回false.</returns>
bool CheckValidExt(string sExt)
{
bool flag=false;
string[] aExt = AllowExt.Split('|');
foreach(string filetype in aExt)
{
if(filetype.ToLower()==sExt)
{
flag = true;
break;
}
}
return flag;
}
/// <summary>
/// 保存图片
/// </summary>
/// <param name="image">Image 对象</param>
/// <param name="savePath">保存路径</param>
/// <param name="ici">指定格式的编解码参数</param>
void SaveImage(System.Drawing.Image image,string savePath,ImageCodecInfo ici)
{
//设置 原图片 对象的 EncoderParameters 对象
EncoderParameters parameters = new EncoderParameters(1);
parameters.Param[0] = new EncoderParameter(Encoder.Quality, ((long) 90));
image.Save(savePath, ici, parameters);
parameters.Dispose();
}
#endregion
#region Methods
/// <summary>
/// 生成缩略图
/// </summary>
/// <param name="sourceImagePath">原图片路径(绝对对路径)</param>
/// <param name="thumbnailImagePath">生成的缩略图路径,如果为空则保存为原图片路径(绝对路径)</param>
/// <param name="thumbnailImageWidth">缩略图的宽度（高度与按源图片比例自动生成）</param>
public void ToThumbnailImages(string sourceImagePath,string thumbnailImagePath,int thumbnailImageWidth)
{
string SourceImagePath = sourceImagePath;
string ThumbnailImagePath = thumbnailImagePath;
int ThumbnailImageWidth = thumbnailImageWidth;
string sExt = SourceImagePath.Substring(SourceImagePath.LastIndexOf(".")).ToLower();
if(SourceImagePath.ToString()==System.String.Empty)
throw new NullReferenceException("SourceImagePathis null!");
if(!CheckValidExt(sExt))
{
throw new ArgumentException("原图片文件格式不正确,支持的格式有[ "+ AllowExt +"]","SourceImagePath");
}
//从 原图片 创建 Image 对象
//System.Drawing.Image image = System.Drawing.Image.FromFile(HttpContext.Current.Server.MapPath(SourceImagePath));
System.Drawing.Image image = System.Drawing.Image.FromFile(SourceImagePath);
//int num = ((ThumbnailImageWidth / 4) * 3);
int width = image.Width;
int height = image.Height;
//计算图片的比例
int num = (int)((float)ThumbnailImageWidth * ((float)height / (float)width));
/*
if ((((double) width) / ((double) height)) >= 1.3333333333333333f)
{
num = ((height * ThumbnailImageWidth) / width);
}
else
{
ThumbnailImageWidth = ((width * num) / height);
}
if ((ThumbnailImageWidth < 1) || (num < 1))
{
return;
}
*/
//用指定的大小和格式初始化 Bitmap 类的新实例
Bitmap bitmap = new Bitmap(ThumbnailImageWidth, num, PixelFormat.Format32bppArgb);
//从指定的 Image 对象创建新 Graphics 对象
Graphics graphics = Graphics.FromImage(bitmap);
//清除整个绘图面并以透明背景色填充
graphics.Clear(Color.Transparent);
//在指定位置并且按指定大小绘制 原图片 对象
graphics.DrawImage(image, new Rectangle(0, 0, ThumbnailImageWidth, num));
image.Dispose();
try
{
//将此 原图片 以指定格式并用指定的编解码参数保存到指定文件
string savepath = (ThumbnailImagePath==null?SourceImagePath:ThumbnailImagePath);
//SaveImage(bitmap,HttpContext.Current.Server.MapPath(savepath),GetCodecInfo((string)htmimes[sExt]));
SaveImage(bitmap,savepath,GetCodecInfo((string)htmimes[sExt]));
}
catch(System.Exception e)
{
throw e;
}
finally
{
bitmap.Dispose();
graphics.Dispose();
}
}
#endregion
}
}
