C#笔记——钉钉机器人推送帆软报表图片（一）
1、前言
2024年最后一个月，家里多了个小公主，在家休息了一段时间。2025年，休完假上班第一天，领导就说：哎，我看总部那边做了个每日产出的报表推送到钉钉群，来看计划达成率。我们基地这边能不能做啊。我心里默默一想，然后大声一喊能做（内心os：上家公司做过类似的功能，不过他们是自己的通讯工具，不是钉钉）。既然有了活，那就开干吧。最终忙活了几天，终于算是实现了这个功能吧，记录下整个过程，以及踩到的坑吧，最终实现效果如图。
2、下载帆软报表图片到本地
因为上家做过类似的功能，那就直接借鉴下之前的代码，先把帆软报表以图片格式下载到本地。大概过程如下
1、在帆软的报表访问页面的url后面添加
&format=image&extype=PNG2、使用http请求访问，下载到本地，添加动态反射以用来传帆软报表的查询条件参数
3、裁剪图片留白区域，添加水印等
public async Task SendImageOutput() {try{//string fineReportUrl = "http://localhost:8075/webroot/decision/view/report?viewlet=tzreport/E04.cpt&format=image&extype=PNG";string image_Path = "D:\\1";string retMsg = string.Empty;DateTime dateTime = DateTime.Now;string time = dateTime.ToString("yyyyMMdd");//当前时间格式string downPath = Path.Combine(image_Path, time);//下载到当前的路径 //方便删除历史的记录文件if (!Directory.Exists(downPath)){Directory.CreateDirectory(downPath);}string startdate = dateTime.AddDays(-7).ToString("yyyy-MM-dd");string enddate = dateTime.ToString("yyyy-MM-dd");string cSharpScript = $"string startdate= \"{startdate}\";string enddate= \"{enddate}\"; var paramlist =\"&startdate=\"+startdate+\"&\"+\"enddate=\"+enddate; return paramlist;";string urlParam = FineReportUrlParam(cSharpScript);string url = fineReportUrl;if (!string.IsNullOrEmpty(urlParam)){url += urlParam;}//下载图片bool downResult = HttpDownloadImage(url, "C02产出", downPath, out string imageFullpath);if (downResult){//发送数据到dingding.......}else{retMsg = "执行失败！";}}catch (Exception ex){throw ex;} }/// <summary> /// http下载文件 /// </summary> /// <param name="url">下载文件地址</param> /// <param name="path">文件存放地址</param> /// <param name="isAddSecurity">是否标密</param> /// <param name="imageNamePrefix">保存的文件的前缀</param> /// <param name="imageFullPath">图片保存到的本地路径</param> /// <returns></returns> public bool HttpDownloadImage(string url, string imageNamePrefix, string path, out string imageFullPath) {try{HttpWebRequest? request = WebRequest.Create(url) as HttpWebRequest;//发送请求并获取相应回应数据HttpWebResponse? response = request.GetResponse() as HttpWebResponse;string fileName = imageNamePrefix + "_" + DateTime.Now.ToString("yyyyMMddHHmmssFFF") + ".png";string fileFullPath = Path.Combine(path, fileName);Stream responseStream = response.GetResponseStream();ImageEditDomain imageEdit = new ImageEditDomain();Bitmap imageBitmap = imageEdit.CutImageWhitePart(responseStream, 80, fileFullPath);Bitmap imageBitmapSecret = imageBitmap;Bitmap imageBitmapWord = imageEdit.AddWatermarkWord(imageBitmapSecret);//加有“MES系统自动发送”的图片imageFullPath = string.Empty;if (imageBitmapWord == null){return false;}else{imageBitmapWord.Save(fileFullPath, ImageFormat.Png);imageFullPath = fileFullPath;return true;}}catch (Exception ex){imageFullPath = string.Empty;return false;} }/// <summary> /// 生成动态代码，方便调用 /// </summary> /// <param name="argMethodCode"></param> /// <returns></returns> public string GenerateCode(string argMethodCode) {StringBuilder sb = new StringBuilder();sb.Append("using System;");sb.Append(Environment.NewLine);sb.Append("namespace FineReport");sb.Append(Environment.NewLine);sb.Append("{");sb.Append(Environment.NewLine);sb.Append(" public class UrlParam");sb.Append(Environment.NewLine);sb.Append(" {");sb.Append(Environment.NewLine);sb.Append(" public string GetParam()");sb.Append(Environment.NewLine);sb.Append(" {");sb.Append(Environment.NewLine);sb.Append(argMethodCode);sb.Append(Environment.NewLine);sb.Append(" }");sb.Append(Environment.NewLine);sb.Append(" }");sb.Append(Environment.NewLine);sb.Append("}");return sb.ToString(); } /// <summary> /// 获取执行动态C#代码的值 /// </summary> /// <param name="argCodeStr"></param> /// <returns></returns> public string FineReportUrlParam(string argCodeStr) {if (string.IsNullOrEmpty(argCodeStr)){return string.Empty;}string code = GenerateCode(argCodeStr);// CSharpCodeProvider objCSharpCodePrivoder = new CSharpCodeProvider();//// CSharpCompilation objCSharpCodePrivoder = new CSharpCompilation();// CompilerParameters objCompilerParameters = new CompilerParameters();// objCompilerParameters.ReferencedAssemblies.Add("System.dll");// //objCompilerParameters.ReferencedAssemblies.Add("Newtonsoft.Json.dll");// objCompilerParameters.GenerateExecutable = false;// objCompilerParameters.GenerateInMemory = true;// CompilerResults cresult = objCSharpCodePrivoder.CompileAssemblyFromSource(objCompilerParameters, code);// // 通过反射，执行代码// Assembly objAssembly = cresult.CompiledAssembly;// object obj = objAssembly.CreateInstance("FineReport.UrlParam");// MethodInfo objMI = obj.GetType().GetMethod("GetParam");// return objMI.Invoke(obj, null)?.ToString();// Parse the source code into a syntax tree.var syntaxTree = CSharpSyntaxTree.ParseText(code);// Define the references that your compiled code will need.var references = new[]{MetadataReference.CreateFromFile(typeof(object).Assembly.Location), // mscorlib/System.Runtime.dllMetadataReference.CreateFromFile(typeof(Console).Assembly.Location), // For example, if you use Console.WriteLine// Add other necessary references here, for example:// MetadataReference.CreateFromFile(typeof(Newtonsoft.Json.JsonConvert).Assembly.Location) // Newtonsoft.Json.dll };// Create a compilation object with the parsed code and references.var compilation = CSharpCompilation.Create(assemblyName: Path.GetRandomFileName(),syntaxTrees: new[] { syntaxTree },references: references,options: new CSharpCompilationOptions(OutputKind.DynamicallyLinkedLibrary));// Emit the compiled code into a memory stream.using (var ms = new MemoryStream()){var result = compilation.Emit(ms);if (!result.Success){var failures = result.Diagnostics.Where(diagnostic =>diagnostic.IsWarningAsError ||diagnostic.Severity == DiagnosticSeverity.Error);throw new Exception("Compilation failed: " + string.Join(Environment.NewLine, failures.Select(d => d.ToString())));}else{ms.Seek(0, SeekOrigin.Begin);// Load the compiled assembly in a separate context to avoid locking issues.var loadContext = new AssemblyLoadContext(null, isCollectible: true);var assembly = loadContext.LoadFromStream(ms);// Use reflection to create an instance of the type and invoke its method.Type? type = assembly.GetType("FineReport.UrlParam");if (type == null)throw new InvalidOperationException("Type 'FineReport.UrlParam' not found.");object obj = Activator.CreateInstance(type)!;MethodInfo? methodInfo = type.GetMethod("GetParam");if (methodInfo == null)throw new InvalidOperationException("Method 'GetParam' not found.");return methodInfo.Invoke(obj, null)?.ToString();}} }using System; using System.Collections.Generic; using System.Drawing; using System.Drawing.Imaging; using System.Linq; using System.Text; using System.Threading.Tasks;namespace DingDingTest {internal class ImageEditDomain{/// <summary>/// 剪去图片空余白边/// </summary>/// <param name="stream">源文件</param>/// <param name="WhiteBar">保留的白边，单位为像素</param>/// <param name="fullPath">保存到本地的地址</param>public Bitmap CutImageWhitePart(Stream stream, int WhiteBar, string fullPath){Bitmap bmp = new Bitmap(stream);int top = 0, left = 0;int right = bmp.Width, bottom = bmp.Height;Color white = Color.White;//寻找最上面的标线,从左(0)到右，从上(0)到下for (int i = 0; i < bmp.Height; i++)//行{bool find = false;for (int j = 0; j < bmp.Width; j++)//列{Color c = bmp.GetPixel(j, i);if (IsWhite(c)){top = i;find = true;break;}}if (find) break;}//寻找最左边的标线，从上（top位）到下，从左到右for (int i = 0; i < bmp.Width; i++)//列{bool find = false;for (int j = top; j < bmp.Height; j++)//行{Color c = bmp.GetPixel(i, j);if (IsWhite(c)){left = i;find = true;break;}}if (find) break; ;}// 寻找最下边标线，从下到上，从左到右for (int i = bmp.Height - 1; i >= 0; i--)//行{bool find = false;for (int j = left; j < bmp.Width; j++)//列{Color c = bmp.GetPixel(j, i);if (IsWhite(c)){bottom = i;find = true;break;}}if (find) break;}//寻找最右边的标线，从上到下，从右往左for (int i = bmp.Width - 1; i >= 0; i--)//列{bool find = false;for (int j = 0; j <= bottom; j++)//行{Color c = bmp.GetPixel(i, j);if (IsWhite(c)){right = i;find = true;break;}}if (find) break;}int iWidth = right - left + 2;int iHeight = bottom - top + 2;bmp = Cut(bmp, left, top, iWidth, iHeight, WhiteBar);return bmp;}/// <summary>/// 添加文字:MES系统自动发送/// </summary>/// <param name="bitmap"></param>/// <returns></returns>public Bitmap AddWatermarkWord(Bitmap bitmap){//添加MES系统标识string text = "MES系统自动发送";int fontSize = 10;Graphics g = Graphics.FromImage(bitmap);int rectWidth = text.Length * (fontSize + 10);int rectHeight = fontSize + 15;//声明矩形域Rectangle rectangle = new Rectangle(bitmap.Width - 200, bitmap.Height - 25, rectWidth, rectHeight);Font font = new Font("微软雅黑", fontSize, FontStyle.Bold); //定义字体SolidBrush backbrush = new SolidBrush(Color.Transparent);SolidBrush sbrushRed = new SolidBrush(Color.Red);var stringFormat = new StringFormat();stringFormat.Alignment = StringAlignment.Center;g.FillRectangle(backbrush, rectangle);g.DrawString(text, font, sbrushRed, rectangle, stringFormat);return bitmap;}/// <summary>/// 对图片进行裁剪/// </summary>/// <param name="b">要裁剪的图片</param>/// <param name="StartX">裁剪的X轴</param>/// <param name="StartY">裁剪的Y轴</param>/// <param name="iWidth">要裁剪的宽度</param>/// <param name="iHeight">要裁剪的高度</param>/// <param name="WhiteBar">保留的白边</param>/// <returns></returns>public Bitmap Cut(Bitmap b, int StartX, int StartY, int iWidth, int iHeight, int WhiteBar){Bitmap bmpOut = new Bitmap(iWidth + 2 * WhiteBar, iHeight + 2 * WhiteBar, PixelFormat.Format24bppRgb);Graphics g = Graphics.FromImage(bmpOut);g.FillRectangle(Brushes.White, new Rectangle(0, 0, iWidth + 2 * WhiteBar, iHeight + 2 * WhiteBar));g.DrawImage(b, new Rectangle(WhiteBar, WhiteBar, iWidth, iHeight), new Rectangle(StartX, StartY, iWidth, iHeight), GraphicsUnit.Pixel);g.Dispose();return bmpOut;}/// <summary>/// 判断白色与否，非纯白色/// </summary>/// <param name="c"></param>/// <returns></returns>public bool IsWhite(Color c){if (c.R < 245 || c.G < 245 || c.B < 245)return true;else return false;}} }
3、使用钉钉机器人发送图片
上一步，我们将帆软图片已经下载到本地了，那么就可以用钉钉机器人推送图片了。这边过程还是比较曲折的，查阅资料，我先使用了SendMessageWithImageAsync这个方法，但是推送到钉钉，确实表情包，无法放大查看图片。
然后，我换了个格式使用SendMessageWithMarkDownAsync方法来推送markdown，这次图片可以正常放大来查看了。
可是，当我将url换成我本地刚下载的帆软报表图片时，却发现推送到钉钉，显示如下。问了下百度发现，钉钉群机器人目前不支持直接推送本地图片，解决方法可以将图片放到钉钉服务器可以http访问的存储服务器上。这下难办了，因为总部安全的策略，这部分只能找总部寻求帮助了。
using System.Text;namespace DingDingTest {public class DingTalkClient{private readonly HttpClient _httpClient;// 钉钉机器人的Webhook URLprivate readonly string webhookUrl = "https://oapi.dingtalk.com/robot/send?access_token={token}";private readonly string title = "MES报障";public DingTalkClient(HttpClient httpClient){_httpClient = httpClient;}/// <summary>/// 发送图片/// </summary>/// <param name="webhookUrl"></param>/// <param name="imageUrl"></param>/// <returns></returns>public async Task SendMessageWithImageAsync(string webhookUrl, string imageUrl){var content = new StringContent($"{{ \"msgtype\": \"image\", \"image\": {{ \"picURL\": \"{imageUrl}\" }} }}", Encoding.UTF8, "application/json");// 发送POST请求var response = await _httpClient.PostAsync(webhookUrl, content);// 输出结果Console.WriteLine(await response.Content.ReadAsStringAsync());}/// <summary>/// 发送markdown/// </summary>/// <param name="webhookUrl"></param>/// <param name="imageUrl"></param>/// <param name="message"></param>/// <returns></returns>public async Task SendMessageWithMarkDownAsync(string webhookUrl, string imageUrl, string message){var content = new StringContent($"{{ \"msgtype\": \"markdown\", \"markdown\": {{ \"title\": \"{message}\", \"text\": \"\" }} }}", Encoding.UTF8, "application/json");// 发送POST请求var response = await _httpClient.PostAsync(webhookUrl, content);// 输出结果Console.WriteLine(await response.Content.ReadAsStringAsync());}} }
4、上传本地图片到gitee
在总部的帮助下，最后也是成功实现了功能，但是我一想，我们平时可以把本地图片上传到gitee，然后钉钉机器人推送的地址改成gitee的图片访问路径不也行吗，说干就干。查看gitee帮助文档。上传成功。
// 要发送的图片URLstring imageUrl = $"https://gitee.com/{user}/{repos}/raw/{branch}/{path}";using System.Text;namespace DingDingTest {internal class UploadImage{private const string AccessToken = {你的令牌};private const string Repository = {你的仓库};private const string Branch = {你的分支};private const string BasePath = "gitee.com";private const string ApiPath = "/api/v5/repos/{user}/{repos}/contents/{path}";public async Task UploadImageAsync(string imagePath, string commitMessage){var imageFileName = Path.GetFileName(imagePath);try{var url = {上传地址};using (var request = new HttpRequestMessage(HttpMethod.Post, url)){string contentType = "application/json";// 设置请求头中的ContentTyperequest.Headers.Accept.Add(new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue(contentType));var data = new{access_token = AccessToken,content = Convert.ToBase64String(System.IO.File.ReadAllBytes(imagePath)), // 这里应该放置你的Base64编码后的图片内容message = commitMessage};string jsonBody = Newtonsoft.Json.JsonConvert.SerializeObject(data);request.Content = new StringContent(jsonBody, Encoding.UTF8, contentType);var client = new HttpClient();client.DefaultRequestHeaders.Authorization = new System.Net.Http.Headers.AuthenticationHeaderValue("token", AccessToken);HttpResponseMessage response = client.Send(request);response.EnsureSuccessStatusCode(); // 抛出异常如果响应不是成功的string responseBody = await response.Content.ReadAsStringAsync().ConfigureAwait(false);Console.WriteLine(responseBody);}}catch (HttpRequestException e){Console.WriteLine("\nException Caught!");Console.WriteLine("Message :{0} ", e.Message);}}} }
5、使用Quartz
添加Quartz,每三分钟执行测试一下，测试OK。
using Quartz; using Quartz.Impl; using System; using System.Threading.Tasks;namespace DingDingTest {internal class Program{static async Task Main(string[] args){// 1. 创建SchedulerIScheduler scheduler = await StdSchedulerFactory.GetDefaultScheduler();// 2. 开启Schedulerawait scheduler.Start();// 3. 创建作业IJobDetail job = JobBuilder.Create<TestJob>().WithIdentity("myJob", "group1").Build();// 4. 创建触发器var trigger = TriggerBuilder.Create().WithIdentity("myTrigger", "group1").StartNow() // 立即启动.WithSimpleSchedule(x => x.RepeatForever() // 重复执行.WithIntervalInMinutes(3)) // 每3min执行一次.Build();// 5. 将作业和触发器添加到调度器await scheduler.ScheduleJob(job, trigger);Console.WriteLine("Press any key to close the application");Console.ReadKey();// 6. 关闭Schedulerawait scheduler.Shutdown();}} }
6、总结
整体思路最后如下：
1、下载帆软报表图片到本地
2、上传图片到公网可ping通的服务器
3、钉钉机器人以markdown方式推送
踩坑如下：
1、因为之前下载帆软报表图片到本地，其中帆软的参数使用的外部脚本，所以使用了using Microsoft.CSharp包的CSharpCodeProvider，来动态执行外部C#脚本代码，来拼接查询的参数，但是因为版本的问题.Net 8 中CSharpCodeProvider被废弃了，所以换成了Microsoft.CodeAnalysis.CSharp。简单使用的话，上诉代码FineReportUrlParam方法可以直接拼接下传参
2、钉钉机器人无法上传本地图片（也不知道百度的对不对，或许有其他方式，哈哈）
3、 上传到gitee上时，HttpResponseMessage response = client.Send(request);可以看到我这边没有使用SendAsync，😭这是因为我使用了异步，vs执行到这里就会崩溃，更改成Send就好了，也不知道为啥。
最好，前后搞了两三天还是实现了该功能，特此记录分享下。
