"C #" WinForm Uploading pictures

1. Drag and drop upload Image 1.1, modify the form properties in the background code, add AllowDrop = True

1.2. Add a drag-and-drop event to the form to find a drag-and-drop on the event list:

Add the following code in the DragDrop generated method:

Private void Form1_dragdrop (object  sender, DragEventArgs e)        {            if  (E.data.getdatapresent ( DataFormats.FileDrop))            {                = dragdropeffects.move;            }             Else             {                = dragdropeffects.none;            }        }

Add the following code in the DragEnter method:

Private voidForm1_dragenter (Objectsender, DragEventArgs e) {            //Judging            string[] files = e.Data.GetData (DataFormats.FileDrop) as string[]; stringFile = files[0]; if(!file. ToLower (). EndsWith (". PNG") &&!file. ToLower (). EndsWith (". jpg") {MessageBox.Show ("need picture File!"); return; }            //PictureBox control Display Pictureimage.load (file); }

2. Click the button to upload the image 2.1, the Official document address: Https://msdn.microsoft.com/zh-cn/library/system.windows.controls.openfiledialog.filter (v= vs.95. aspx2.2, adding control OpenFileDialog to the form, provides the ability to prompt the user to open the file. button to add the following code:

Private void button1_click (object  sender, EventArgs e)        {            if ( Openfiledialog.showdialog () = = DialogResult.OK            )                {//PictureBox control display picture                 image.load (openfiledialog.filename);            }        }

2.3, upload pictures and save

Private voidButton1_Click (Objectsender, EventArgs e) {            if(Openfiledialog.showdialog () = =DialogResult.OK) {//PictureBox control Display Pictureimage.load (openfiledialog.filename); //gets the suffix name of the user-selected file                stringExtension =path.getextension (openfiledialog.filename); //declaring the allowed suffix names                string[] str =New string[] {". gif",". Jpge",". jpg",". PNG" }; if(!Str. Contains (extension)) {MessageBox.Show ("only images in gif,jpge,jpg format can be uploaded! "); }                Else                {                    //gets the file selected by the user and determines that the file size cannot exceed 20k,fileinfo.length in bytes.FileInfo FileInfo =NewFileInfo (openfiledialog.filename); if(Fileinfo.length >20480) {MessageBox.Show ("the uploaded image cannot be larger than 20K"); }                    Else                    {                        //Absolute Path                        stringImage =Openfiledialog.filename; //it means xxx.jpg .                        stringPicpath =Openfiledialog.safefilename; File.Copy (Openfiledialog.filename, Application.startuppath+"\\Image\\"+Picpath); }                }            }        }

"C #" WinForm Uploading pictures