前台
<form id="Form1" method="post" runat="server" enctype="multipart/form-data">
<table id="Table1" cellpadding="1" cellspacing="1" width568 border="1">
<tr>
<td>
<asp:Label ID="Label1" Runat="server">要上传的图片</asp:Label>
</td>
<td>
<input id="upImage" type="file" name="File1" runat="server"></td>
<td><asp:Button ID="btnUp" Runat="server" Text="上传并生成缩图"></asp:Button></td>
</tr>
<tr>
<td><asp:Label ID="Label2" Runat="server">原图片</asp:Label></td>
<td align="center" colspan="2"><asp:Image ID="imageSource" Runat="server"></asp:Image>
</td>
</tr>
<tr>
<td><asp:Label ID="Label3" Runat="server">缩图</asp:Label></td>
<td align="center" colspan="2">
<asp:Image ID="imageSmall" Runat="server"></asp:Image></td>
</tr>
</table>
</form>
后台
public System.Drawing.Image image,newimage;//定义
protected string imagePath;
protected string imageType;
protected string imageName;
//提供一个回调方法,用于确定Image对象在执行生成缩图操作时河时提前取消执行
//如果此方法确定GetThumbnailImage方法应该提前停此执行,返回true 否则返回false
protected System.Drawing.Image.GetThumbnailImageAbort callb=null;
private void btnUp_Click(object sender, System.EventArgs e)
{
string mPath;
if(""!=upImage.PostedFile.FileName)
{
imagePath=upImage.PostedFile.FileName;
//取的图片类型
imageType=imagePath.Substring(imagePath.LastIndexOf(".")+1);
//取得图片名称
imageName=imagePath.Substring(imagePath.IndexOf("\\")+1);
if("jpg"!=imageType&&"gif"!=imageType)
{
Response.Write("<script laguage='javascript'>alert('请选择jpg和gif图片');</script>");
return;
}
else
{
try
{ //建立虚拟路径
mPath=Server.MapPath(upFile);
//保存到虚拟目录
upImage.PostedFile.SaveAs(mPath+"\\"+imageName);
//显示原图片
imageSource.ImageUrl="upFile"+imageName;
//为上传的图片建立应用
image=System.Drawing.Image.FromFile(mPath+"\\"+imageName);
//生存缩图
newimage=image.GetThumbnailImage(300,300,callb,new System.IntPtr());
//把缩图保存到指定的虚拟路径
newimage.Save(Server.MapPath("upFile")+"\\small"+imageName);
//释放image对象占用的资源
image.Dispose();
newimage.Dispose();
imageSmall.ImageUrl="upFile/"+"small"+imageName;
this.Response.Write("上传成功");
}
catch
{
this.Response.Write(" 上传失败");
}
}
}
}
