Asp.net Image Upload and thumbnail generation

Using system; using system. data; using system. configuration; using system. web; using system. web. security; using system. web. ui; using system. web. UI. webcontrols; using system. web. UI. webcontrols. webparts; using system. web. UI. htmlcontrols; using system. io; using system. text; using system. drawing; /// <summary> /// Image Upload class // </Summary> public class uploadimg {public uploadimg () {}/ * call: after instantiating the class, set the desired attribute. Uploadimg (this. fileupload1) input the ID of the file upload control as the parameter. */Private Static string _ MSG; private string ofullname; // The complete path for saving. original Image private string tfullname; // The complete path for saving. thumbnail Private Static string _ ofilename; // The Name Of The saved image. original Image private string tfilename; // The image name when it is saved. thumbnail // Private string _ tfullname = "0"; // Private string _ ofilename = "0"; // Private string _ tfilename = "0 "; private string _ tprefix = "small _"; private int _ limitwidth = 3072; private int _ limitheight = 2304; private int _ twidth = 100; private int _ theight = 100; private int _ size = 3000000; private bool _ israte; private bool _ iscreate; private string _ Path = "Upload"; // <summary> // information // </Summary> Public static string MSG {get {return _ MSG ;} set {_ MSG = value ;}/// <summary> /// thumbnail prefix /// </Summary> Public String tprefix {get {return _ tprefix ;} set {_ tprefix = value ;}/// <s Ummary >/// maximum width of the source image /// </Summary> Public int limitwidth {get {return _ limitwidth;} set {_ limitwidth = value ;}} /// <summary> /// maximum height of the source image /// </Summary> Public int limitheight {get {return _ limitheight;} set {_ limitheight = value ;}} /// <summary> /// maximum width of the thumbnail /// </Summary> Public int twidth {get {return _ twidth;} set {_ twidth = value ;}} /// <summary> /// maximum height of the thumbnail /// </Summary> Publ IC int theight {get {return _ theight;} set {_ theight = value ;}} /// <summary> /// file size /// </Summary> Public int size {get {return _ size;} set {_ size = value ;}} /// <summary> /// proportional to/// </Summary> Public bool israte {get {return _ israte;} set {_ israte = value ;}} /// <summary> /// whether to generate a thumbnail // </Summary> Public bool iscreate {get {return _ iscreate;} set {_ iscreate = value ;}} /// <Summary> /// name of the folder where the image is stored /// </Summary> Public String path {get {return _ path ;} set {_ Path = value ;}/// <summary> // source image name /// </Summary> Public static string ofilename {get {return _ ofilename ;} set {_ ofilename = value ;}/// <summary> // Image Upload (default: "proportional compression, limited upload size: 2048*1536, thumbnail size: 100*100, the upload size is limited to 1 MB and is stored in the root directory upload ") /// </Summary> /// <Param name = "uploadfile"> File Upload Control </param> /// <return S> whether the image is successfully saved </returns> Public bool uploadimg (fileupload uploadfile) {If (uploadfile. hasfile) // check whether the selected file {string filename = uploadfile. filename. tolower (); int I = filename. lastindexof (". "); filename = filename. substring (I, filename. length-I); If (! (Filename = ". jpg "| filename = ". JPEG "| filename = ". GIF "| filename = ". PNG "| filename = ". BMP ") {MSG =" the file format is incorrect. It can only be JPEG, JPG, GIF, PNG or BMP! "; Return false;} // check whether the format of the uploaded file is valid if (uploadfile. postedfile. contentlength = 0 | uploadfile. postedfile. contentlength> = size) {MSG = string. format ("the image size should be smaller than {0} m! ", Math. round (_ size/1024.0/1024.0, 2); Return false;} // check the image file size // generate the source image stream ostream = uploadfile. postedfile. inputstream; system. drawing. image oimage = system. drawing. image. fromstream (ostream); int owidth = oimage. width; // source Image Width int oheight = oimage. height; // source Image Height if (owidth> limitwidth | oheight> limitheight) {MSG = string. format ("image size should be less than {0} * {1}", _ limitwidth, this. _ limitheight); Return false ;} // Check whether the size exceeds the specified size if (israte) {// calculate the width and height of the thumbnail proportionally if (owidth> = oheight) {theight = (INT) math. floor (convert. todouble (oheight) * (convert. todouble (twidth)/convert. todouble (owidth); // equals set height} else {twidth = (INT) math. floor (convert. todouble (owidth) * (convert. todouble (theight)/convert. todouble (oheight); // proportional width} // generate the thumbnail image bitmap timage = new Bitmap (twidth, theight); graphics G = graphics. fromi MAGE (timage); G. interpolationmode = system. drawing. drawing2d. interpolationmode. highqualitybicubic; // set the high quality interpolation method G. smoothingmode = system. drawing. drawing2d. smoothingmode. highquality; // set high quality, low speed rendering smoothness G. clear (color. transparent); // clear the canvas and fill g with a transparent background color. drawimage (oimage, new rectangle (0, 0, twidth, theight), new rectangle (0, 0, owidth, oheight), graphicsunit. pixel); random orandom = new random (); string ostr Ingrandom = orandom. next (1, 999999999 ). tostring (); // generate nine random numbers // format the date as the file name string ostringtime = string. format ("{0: yyyymmddhhmmss}", datetime. now); ofilename = ostringtime + ostringrandom + filename; tfilename = tprefix + ostringtime + ostringrandom + filename; string savepath = httpcontext. current. server. mappath ("~ ") +" \ "+ Path +" \ "; if (! Directory. exists (savepath) {directory. createdirectory (savepath); // create a folder under the root directory} ofullname = savepath + ofilename; tfullname = savepath + tfilename; // start to save the image to the server try {Switch (filename) {Case ". JPEG ": Case ". jpg ": {oimage. save (ofullname, system. drawing. imaging. imageformat. JPEG); If (iscreate) timage. save (tfullname, system. drawing. imaging. imageformat. JPEG); break;} case ". GIF ": {oimage. save (ofulln Ame, system. drawing. imaging. imageformat. GIF); If (iscreate) timage. save (tfullname, system. drawing. imaging. imageformat. GIF); break;} case ". PNG ": {oimage. save (ofullname, system. drawing. imaging. imageformat. PNG); If (iscreate) timage. save (tfullname, system. drawing. imaging. imageformat. PNG); break;} case ". BMP ": {oimage. save (ofullname, system. drawing. imaging. imageformat. BMP); If (iscreate) timage. SA Ve (tfullname, system. Drawing. imaging. imageformat. BMP); break ;}} MSG = "image uploaded successfully! "; // Save path + complete file name string _ savepath ="/"+ path +"/"; ofullname = _ savepath + ofilename; tfullname = _ savepath + tfilename; return true;} catch (exception ex) {MSG = ex. message; return false;} finally {// release resource oimage. dispose (); G. dispose (); timage. dispose () ;}} else {MSG = "select the image to upload first! "; Return false ;}}}