现在需要创建一个场景二维码，除了基础的微信接口创建外，需要加上小logo，思路如下：
1、 首先根据微信的开发文档创建二维码，获取二维码的url，没啥可说的，按照文档来就好了
获取到的二维码就是这么素净~
2、得到了下载地址，我们就已文件流的方式，将二维码的流，转换为图像对象，并将指定的图片转换为图像对象（注意：地址必须是绝对路径
/// <summary>
/// 下载二维码图片
/// </summary>
/// <param name="dirName">文件路径</param>
/// <param name="fileName">文件名</param>
/// <param name="downloadUrl">下载地址</param>
/// <param name="url">最终图片存放地址</param>
/// <returns></returns>
private string LoadImg(string dirName,string fileName,string downloadUrl, out string url)
{
//设置文件保存的地址，格式，文件夹的判断和创建
string urlPath =CreateUrl(dirName,fileName, out url);// out 文件路径 HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(downloadUrl);
req.Method = "GET";
using (WebResponse wr = req.GetResponse())
{
HttpWebResponse myResponse = (HttpWebResponse)req.GetResponse();
string strpath = myResponse.ResponseUri.ToString();
WebClient mywebclient = new WebClient(); //开始了
//素净的二维码
byte[] bytelist = mywebclient.DownloadData(strpath); MemoryStream ms1 = new MemoryStream(bytelist);
Bitmap b1 = (Bitmap)Image.FromStream(ms1);
ms1.Close(); //logo图片
Bitmap b2 = new Bitmap(AppDomain.CurrentDomain.BaseDirectory + @"logo\logo3.png"); //合并
var ret = new ImageUtility().MergeQrImg(b1, b2, );
Image img = ret;
img.Save(AppDomain.CurrentDomain.BaseDirectory + urlPath);
string path = urlPath;
//返回最终路径
return path;
}
}
这个是合并图片使用到的帮助类，自己领悟
logo大小的调整、边框颜色的调整在帮助类中可以自行设置。
public static Bitmap GetThumbnail(Bitmap b, int destHeight, int destWidth)
{
System.Drawing.Image imgSource = b;
System.Drawing.Imaging.ImageFormat thisFormat = imgSource.RawFormat;
int sW = , sH = ;
// 按比例缩放
int sWidth = imgSource.Width;
int sHeight = imgSource.Height;
if (sHeight > destHeight || sWidth > destWidth)
{
if ((sWidth * destHeight) > (sHeight * destWidth))
{
sW = destWidth;
sH = (destWidth * sHeight) / sWidth;
}
else
{
sH = destHeight;
sW = (sWidth * destHeight) / sHeight;
}
}
else
{
sW = sWidth;
sH = sHeight;
}
Bitmap outBmp = new Bitmap(destWidth, destHeight);
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((destWidth - sW) / , (destHeight - sH) / , sW, sH), , , imgSource.Width, imgSource.Height, GraphicsUnit.Pixel);
g.Dispose();
// 以下代码为保存图片时，设置压缩质量
EncoderParameters encoderParams = new EncoderParameters();
long[] quality = new long[];
quality[] = ;
EncoderParameter encoderParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, quality);
encoderParams.Param[] = encoderParam;
imgSource.Dispose();
return outBmp;
}
} public class ImageUtility
{
#region 合并用户QR图片和用户头像
/// <summary>
/// 合并用户QR图片和用户头像
/// </summary>
/// <param name="qrImg">QR图片</param>
/// <param name="headerImg">用户头像</param>
/// <param name="n">缩放比例</param>
/// <returns></returns>
public Bitmap MergeQrImg(Bitmap qrImg, Bitmap headerImg, double n = 0.23)
{
int margin = ;
float dpix = qrImg.HorizontalResolution;
float dpiy = qrImg.VerticalResolution;
var _newWidth = ( * qrImg.Width - * margin) * 1.0f / ;
var _headerImg = ZoomPic(headerImg, _newWidth / headerImg.Width);
//处理头像
int newImgWidth = _headerImg.Width + margin;
Bitmap headerBgImg = new Bitmap(newImgWidth, newImgWidth);
headerBgImg.MakeTransparent();
Graphics g = Graphics.FromImage(headerBgImg);
g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
g.Clear(Color.Transparent);
Pen p = new Pen(new SolidBrush(Color.White));
//位置和大小
Rectangle rect = new Rectangle(, , newImgWidth - , newImgWidth - );
using (GraphicsPath path = CreateRoundedRectanglePath(rect, ))
{
g.DrawPath(p, path);
g.FillPath(new SolidBrush(Color.White), path);
}
//画头像
Bitmap img1 = new Bitmap(_headerImg.Width, _headerImg.Width);
Graphics g1 = Graphics.FromImage(img1);
g1.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
g1.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
g1.Clear(Color.Transparent);
//Pen p1 = new Pen(new SolidBrush(Color.Gray));
Pen p1 = new Pen(new SolidBrush(Color.White));
Rectangle rect1 = new Rectangle(, , _headerImg.Width - , _headerImg.Width - );
using (GraphicsPath path1 = CreateRoundedRectanglePath(rect1, ))
{
g1.DrawPath(p1, path1);
TextureBrush brush = new TextureBrush(_headerImg);
g1.FillPath(brush, path1);
}
g1.Dispose();
PointF center = new PointF((newImgWidth - _headerImg.Width) / , (newImgWidth - _headerImg.Height) / );
g.DrawImage(img1, center.X, center.Y, _headerImg.Width, _headerImg.Height);
g.Dispose();
Bitmap backgroudImg = new Bitmap(qrImg.Width, qrImg.Height);
backgroudImg.MakeTransparent();
backgroudImg.SetResolution(dpix, dpiy);
headerBgImg.SetResolution(dpix, dpiy);
Graphics g2 = Graphics.FromImage(backgroudImg);
g2.Clear(Color.Transparent);
g2.DrawImage(qrImg, , );
PointF center2 = new PointF((qrImg.Width - headerBgImg.Width) / , (qrImg.Height - headerBgImg.Height) / );
g2.DrawImage(headerBgImg, center2);
g2.Dispose();
return backgroudImg;
}
#endregion #region 图形处理
/// <summary>
/// 创建圆角矩形
/// </summary>
/// <param name="rect">区域</param>
/// <param name="cornerRadius">圆角角度</param>
/// <returns></returns>
private GraphicsPath CreateRoundedRectanglePath(Rectangle rect, int cornerRadius)
{
//下午重新整理下，圆角矩形
GraphicsPath roundedRect = new GraphicsPath();
roundedRect.AddArc(rect.X, rect.Y, cornerRadius * , cornerRadius * , , );
roundedRect.AddLine(rect.X + cornerRadius, rect.Y, rect.Right - cornerRadius * , rect.Y);
roundedRect.AddArc(rect.X + rect.Width - cornerRadius * , rect.Y, cornerRadius * , cornerRadius * , , );
roundedRect.AddLine(rect.Right, rect.Y + cornerRadius * , rect.Right, rect.Y + rect.Height - cornerRadius * );
roundedRect.AddArc(rect.X + rect.Width - cornerRadius * , rect.Y + rect.Height - cornerRadius * , cornerRadius * , cornerRadius * , , );
roundedRect.AddLine(rect.Right - cornerRadius * , rect.Bottom, rect.X + cornerRadius * , rect.Bottom);
roundedRect.AddArc(rect.X, rect.Bottom - cornerRadius * , cornerRadius * , cornerRadius * , , );
roundedRect.AddLine(rect.X, rect.Bottom - cornerRadius * , rect.X, rect.Y + cornerRadius * );
roundedRect.CloseFigure();
return roundedRect;
}
/// <summary>
/// 图片按比例缩放
/// </summary>
private Image ZoomPic(Image initImage, double n)
{
//缩略图宽、高计算
double newWidth = initImage.Width;
double newHeight = initImage.Height;
newWidth = n * initImage.Width;
newHeight = n * initImage.Height;
//生成新图
//新建一个bmp图片
System.Drawing.Image newImage = new System.Drawing.Bitmap((int)newWidth, (int)newHeight);
//新建一个画板
System.Drawing.Graphics newG = System.Drawing.Graphics.FromImage(newImage);
//设置质量
newG.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
newG.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
//置背景色
newG.Clear(Color.Transparent);
//画图
newG.DrawImage(initImage, new System.Drawing.Rectangle(, , newImage.Width, newImage.Height), new System.Drawing.Rectangle(, , initImage.Width, initImage.Height), System.Drawing.GraphicsUnit.Pixel);
newG.Dispose();
return newImage;
}
最后生成的图片类似这样：
