C#图片按比例缩放实例
程序员文章站
2023-11-22 13:39:52
本文实例为大家分享了c#图片按比例缩放的具体代码,供大家参考,具体内容如下
工具类代码:
using system;
using system.col...
本文实例为大家分享了c#图片按比例缩放的具体代码,供大家参考,具体内容如下
工具类代码:
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> /// 图片缩放 /// </summary> public class zoomimageutil { /// <summary> /// 图片缩放 /// </summary> /// <param name="bmp">图片</param> /// <param name="width">目标宽度,若为0,表示宽度按比例缩放</param> /// <param name="height">目标长度,若为0,表示长度按比例缩放</param> public static bitmap getthumbnail(bitmap bmp, int width, 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); // 设置画布的描绘质量 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; } } }
使用示例:
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() { initializecomponent(); } 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 == "" && txtheight.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(filename), 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("进度:{1}/{0}", openfiledialog1.filenames.length, ++i); })); thread.sleep(1); } messagebox.show("成功!"); }); } } catch (exception ex) { messagebox.show(ex.message); } } } /// <summary> /// 跨线程访问控件的委托 /// </summary> public delegate void invokedelegate(); }
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持。
上一篇: 自媒体变现 你该思考的问题!
下一篇: 互联网产品运营中的用户认识误区