用ASP.NET上传图片并生成带版权信息的缩略图

OStack程序员社区-中国程序员成长平台 › 门户 › 编程› ASP.NET›ASP.NET编程经验

原作者: [db:作者] 来自: [db:来源] 收藏邀请

<%@ Page Language="C#" ResponseEncoding="gb2312" %>
<%@ import Namespace="System" %>
<%@ import Namespace="System.IO" %>
<%@ import Namespace="System.Drawing" %>
<%@ import Namespace="System.Drawing.Imaging" %>
<script runat="server">

void Page_Load(Object sender, EventArgs e)
{
if(!Page.IsPostBack)
{
ImgPreview.Visible=false;
}
}
void GetThumbnailImage(int width,int height,string strInfo,int left,int right)
{
string file="Uploads/"+uploadFile.PostedFile.FileName.Substring(uploadFile.PostedFile.FileName.LastIndexOf(''\\'')+1);
string newfile="Uploads/"+uploadFile.PostedFile.FileName.Substring(uploadFile.PostedFile.FileName.LastIndexOf(''\\'')+1)+".jpg";
string strAdd=strInfo;
System.Drawing.Image oldimage = System.Drawing.Image.FromFile(Server.MapPath(file));
System.Drawing.Image thumbnailImage =
oldimage.GetThumbnailImage(width, height,new System.Drawing.Image.GetThumbnailImageAbort(ThumbnailCallback), IntPtr.Zero);
Response.Clear();
Bitmap output=new Bitmap(thumbnailImage);
Graphics g=Graphics.FromImage(output);
g.DrawString(strAdd,new Font("Courier New", 14),new SolidBrush(Color.Red),left,right);
output.Save(Server.MapPath(newfile),System.Drawing.Imaging.ImageFormat.Jpeg);
Response.ContentType = "image/gif";
ImgPreview.Visible=true;
ImgPreview.ImageUrl=newfile;
}
bool ThumbnailCallback()
{
return true;
}

void Button_Click(object sender, EventArgs e)
{
int width,height,left,right;
string strAddInfo=txtAddInfo.Text;
width=Int32.Parse(txtWidth.Text);
height=Int32.Parse(txtHeight.Text);
left=Int32.Parse(txtLeft.Text);
right=Int32.Parse(txtRight.Text);
if(!(uploadFile.PostedFile.ContentLength>0))
{
lblErrInfo.Text="没有选择文件";
}
else
{

string path = Server.MapPath("./Uploads/"+uploadFile.PostedFile.FileName.Substring(uploadFile.PostedFile.FileName.LastIndexOf(''\\'')+1));
if(File.Exists(path))
{
lblErrInfo.Text="已经有同名文件";
}
else
{
uploadFile.PostedFile.SaveAs(path);
GetThumbnailImage(width,height,strAddInfo,left,right);
}
}
}
</script>
<html>
<head>
</head>
<body>
<form method="post" enctype="multipart/form-data" runat="server">
<p>
<input ></asp:Image>
</p>

</form>
</body>
</html>