使用Graphics合成帶二維碼和頭像的分享圖(小程式分享、App分享)
阿新 • • 發佈：2020-08-06
適用於微信小程式分享圖、app分享圖
//分享的海報背景圖片 使用本地圖片檔案 string path = Server.MapPath("/Content/images/backimg.jpg"); Image imgSrc = Image.FromFile(path); //將檔案載入成圖片格式 //二維碼圖片檔案 使用遠端圖片檔案 var qr_url="http://xxxxxx:8001/Images/qrimg.jpg"; Image qrCodeImage= ReduceImage(qr_url, 122, 122); //頭像檔案 使用遠端圖片檔案 var headurl="http://xxxxxx:8001/Images/header.jpg"; Image headImage= ReduceImage(headurl, 59, 59); //開始合成圖片 宣告畫圖工具 using (Graphics g = Graphics.FromImage(imgSrc)) { //畫推廣二維碼 宣告起始座標點 //從x軸30畫素處、y軸的40畫素處開始畫 int qr_x = 30,qr_y = 40; //指定二維碼在合成圖上顯示的座標和區域大小 Rectangle destRect = new Rectangle(qr_x, qr_y, qrCodeImage.Width, qrCodeImage.Height);//在destRect宣告的區域內，開始繪製二維碼 Rectangle srcRect = new Rectangle(0, 0, qrCodeImage.Width, qrCodeImage.Height); //開始繪製 GraphicsUnit.Pixel 表示以畫素為單位 g.DrawImage(qrCodeImage, destRect, srcRect, GraphicsUnit.Pixel); //畫頭像 裁剪頭像(圓形) Image header = CutEllipse(titleImage, new Size(59, 59)); int w = header.Width, h = header.Height; //圖片寬高 int x = 24, y = 982; //圖片座標 g.DrawImage(header, new Rectangle(x, y, w, h), new Rectangle(0, 0, w, h), GraphicsUnit.Pixel); //畫暱稱 思源黑體 CN 常規 字型大小18 粗體 Font font = new Font("Source Han Sans CN Regular", 18, FontStyle.Bold, GraphicsUnit.Pixel); Color fontColor = (Color)new ColorConverter().ConvertFromString("#999999"); g.DrawString("張三", font, new SolidBrush(fontColor), 100, 990); //座標點 x=100 y=990 //畫其他文字 思源黑體 CN 常規 var othertext = "邀請您看直播"; g.DrawString(othertext, font, new SolidBrush(fontColor), 101, 1014); //座標點 x=100 y=990 header.Dispose(); g.Dispose(); } //獲取系統編碼型別陣列,包含了jpeg,bmp,png,gif,tiff int quality = 50; //影象質量 1 - 100的範圍 ImageCodecInfo[] icis = ImageCodecInfo.GetImageEncoders(); ImageCodecInfo ici = null; foreach (ImageCodecInfo i in icis) { if (i.MimeType == "image/jpeg" || i.MimeType == "image/bmp" || i.MimeType == "image/png" || i.MimeType == "image/gif") { ici = i; } } EncoderParameters ep = new EncoderParameters(1); ep.Param[0] = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, quality); //將圖片轉換成二進位制流 MemoryStream ms = new MemoryStream();//讀取位元組流 imgSrc.Save(ms, ici, ep); var buffer = ms.GetBuffer(); //圖片流 ms.Dispose(); imgSrc.Dispose(); qrCodeImage.Dispose(); headImage.Dispose(); ep.Dispose();
ReduceImage 方法可以縮放圖片大小
1 /// <summary> 2 /// 縮小/放大圖片 3 /// </summary> 4 /// <param name="url">圖片網路地址</param> 5 /// <param name="toWidth">縮小/放大寬度</param> 6 /// <param name="toHeight">縮小/放大高度</param> 7 /// <returns></returns> 8 private static Image ReduceImage(string url, int toWidth, int toHeight, string param = null) 9 { 10 try 11 { 12 Stream responseStream = null; 13 if (param != null) //post請求 14 { 15 var intResult = HttpHelper.HttpClientPost(url, param, out responseStream); 16 } 17 else 18 { 19 WebRequest request = WebRequest.Create(url); 20 WebResponse response = request.GetResponse(); 21 responseStream = response.GetResponseStream(); 22 } 23 if (responseStream == null) 24 { 25 return null; 26 } 27 28 Image originalImage = Image.FromStream(responseStream); 29 if (toWidth <= 0 && toHeight <= 0) //返回原圖 30 { 31 return originalImage; 32 } 33 else if (toWidth > 0 && toHeight > 0) ////給了寬*高 如果原始小，則返回原圖 34 { 35 if (originalImage.Width < toWidth && originalImage.Height < toHeight) 36 return originalImage; 37 } 38 else if (toWidth <= 0 && toHeight > 0) //給了高,根據高計算寬，得出正方形圖片 39 { 40 if (originalImage.Height < toHeight) 41 return originalImage; 42 toWidth = originalImage.Width * toHeight / originalImage.Height; 43 } 44 else if (toHeight <= 0 && toWidth > 0) //給了寬,根據寬計算高，得出正方形圖片 45 { 46 if (originalImage.Width < toWidth) 47 return originalImage; 48 toHeight = originalImage.Height * toWidth / originalImage.Width; 49 } 50 Image toBitmap = new Bitmap(toWidth, toHeight); //定義一個指定大小的畫布背景 51 using (Graphics g = Graphics.FromImage(toBitmap)) //定義畫圖工具，使用畫圖工具載入畫布背景,開始在畫布上作圖 52 { 53 //圖片縮放時使用 54 g.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighSpeed; //高速度、低質量 55 g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic; //影象縮放質量 56 //生成圖片時使用 57 g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality; //圖片呈現質量，即消除鋸齒 58 g.Clear(Color.Transparent); //清除背景色，並設定顏色為透明 Color.Transparent 59 g.DrawImage(originalImage, 60 new Rectangle(0, 0, toWidth, toHeight), 61 new Rectangle(0, 0, originalImage.Width, originalImage.Height), 62 GraphicsUnit.Pixel); 63 originalImage.Dispose(); 64 responseStream.Dispose(); 65 g.Dispose(); 66 return toBitmap; 67 } 68 } 69 catch (Exception ex) 70 { 71 throw; 72 } 73 }
CutEllipse方法用來裁剪頭像
1 /// <summary> 2 /// 畫圓形頭像 3 /// </summary> 4 /// <param name="img">待裁剪的圖片</param> 5 /// <param name="size">裁剪大小</param> 6 /// <returns></returns> 7 private static Image CutEllipse(Image img, Size size) 8 { 9 try 10 { 11 var rec = new Rectangle(0, 0, size.Width, size.Height); //宣告位置和大小 12 Bitmap bitmap = new Bitmap(size.Width, size.Height); //宣告畫布並指定大小 13 Pen p = new Pen(Color.Transparent); //宣告透明色畫筆 14 using (Graphics g = Graphics.FromImage(bitmap)) 15 { 16 using (TextureBrush br = new TextureBrush(img, rec)) //宣告畫刷 17 { 18 g.SmoothingMode = SmoothingMode.HighQuality; //使繪圖質量最高，即消除鋸齒 19 g.InterpolationMode = InterpolationMode.HighQualityBicubic; 20 g.CompositingQuality = CompositingQuality.HighQuality; 21 22 g.FillEllipse(br, rec); //根據指定大小和位置填充圓形 23 g.DrawEllipse(p, rec); //畫圓形圖 24 br.Dispose(); 25 } 26 g.Dispose(); 27 } 28 return bitmap; 29 } 30 catch (Exception ex) 31 { 32 throw; 33 } 34 }
效果圖：