C # Pictures Proportionally scaled sample code share

This article mainly for you in detail the C # picture scaled by the example, with a certain reference value, interested in small partners can refer to

The example of this article for everyone to share the C # picture proportionally scaled specific code for your reference, the specific content is as follows

Tool Class Code:

Using system;using system.collections.generic;using system.drawing;using system.drawing.drawing2d;using System.drawing.imaging;using system.linq;using system.text;using system.threading.tasks;namespace ZoomImage.Utils{ <summary>///Picture scaling///</summary> public class Zoomimageutil {///<summary>//Picture scaling//</su mmary>//<param name= "bmp" > Pictures </param>///<param Name= "width" > target width, if 0, indicates the width is scaled proportionally </param >//<param name= "height" > target length, if 0, indicates proportional scaling of length </param> public static Bitmap GetThumbnail (Bitmap bmp, int w idth, int height) {if (width = = 0) {width = height * bmp. Width/bmp.   Height; } if (height = = 0) {height = width * bmp. Height/bmp.   Width;   } Image Imgsource = BMP;   Bitmap outbmp = new Bitmap (width, height);   Graphics g = graphics.fromimage (outbmp);   G.clear (color.transparent);   Set the drawing quality of the canvas g.compositingquality = compositingquality.highquality; G.smoothingmode = smoothingmode.highquality;   G.interpolationmode = Interpolationmode.highqualitybicubic; G.drawimage (Imgsource, New Rectangle (0, 0, Width, height + 1), 0, 0, imgsource.width, Imgsource.height, GraphicsUnit.Pixel   );   G.dispose ();   Imgsource.dispose (); Bmp.   Dispose ();  return outbmp; } }}

Examples of Use:

Using system;using system.collections.generic;using system.componentmodel;using system.data;using System.Drawing; Using system.io;using system.linq;using system.text;using system.threading;using system.threading.tasks;using system.windows.forms;using zoomimage.utils;namespace zoomimage{public partial class Form1:form {public Form1 () {I  Nitializecomponent ();  } private void Form1_Load (object sender, EventArgs e) {openfiledialog1.multiselect = true; } private void Txtwidth_keypress (object sender, KeyPressEventArgs e) {if (E.keychar! = 8 &&!)   Char.isdigit (E.keychar)) {e.handled = true; }} private void Txtheight_keypress (object sender, KeyPressEventArgs e) {if (E.keychar! = 8 &&!)   Char.isdigit (E.keychar)) {e.handled = true; }} private void Btnselectimage_click (object sender, EventArgs e) {try {if (Txtwidth.text = = "" && txt    Height.text = = "") {return; } if (openfiledialog1.showdialog () = = DialogResult.OK) {Task.Factory.StartNew (() = {String path = Path.getdirectoryname (Openfiledialog1.filenames[0]) +      "\\NewImage\\";      int i = 0; foreach (String fileName in Openfiledialog1.filenames) {Bitmap bmp = Zoomimageutil.getthumbnail (new Bitmap (fil ename), convert.toint32 (Txtwidth.text = = ""? " 0 ": Txtwidth.text), convert.toint32 (Txtheight.text = =" "?")       0 ": txtheight.text)); if (!       Directory.Exists (Path)) {directory.createdirectory (path);       } file.delete (Path + path.getfilename (fileName)); Bmp.       Save (path + path.getfilename (fileName)); This. Invoke (new invokedelegate () = {Lblprogress.text = string.       Format ("Progress: {1}/{0}", OpenFileDialog1.FileNames.Length, ++i);       }));      Thread.Sleep (1); } MessageBox.Show ("Success!     ");    }); }} catch (Exception ex) {MessageBox.Show (ex).   Message); }}}///<summary>//delegate access to the control's delegates////</summary> public delegate void InvoKedelegate ();}