用ASP.NET上传图片并生成带版权信息的缩略图

作者：zhaozj
发表时间：2020-12-23 10:38
来源：未知

<%@ 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 id="uploadFile" type="file" runat="server" /><asp:Label id="lblErrInfo" runat="server" forecolor="Red"></asp:Label></p><p>width:<asp:TextBox id="txtWidth" runat="server" Width="40px">100</asp:TextBox> height:<asp:TextBox id="txtHeight" runat="server" Width="40px">150</asp:TextBox> </p><p>添加信息：<asp:TextBox id="txtAddInfo" runat="server">AspxBoy.Com</asp:TextBox></p><p>信息位置：left:<asp:TextBox id="txtLeft" runat="server" Width="40px">10</asp:TextBox> right:<asp:TextBox id="txtRight" runat="server" Width="40px">135</asp:TextBox></p><p> <input id="button" type="button" value="上传生成缩略图" onServerClick="Button_Click" runat="server" /></p><p><asp:Image id="ImgPreview" runat="server"></asp:Image></p></form></body></html>