Lire le processus StandardOutput avant la nouvelle ligne reçue

Voici une solution à votre problème, mais un peu délicate, car gdalwarp.exe bloque la sortie standard, vous pouvez redirect sa sortie vers un fichier et lire les modifications qui y sont apscopes. Il était possible d’utiliser FileSystemWatcher pour détecter les modifications de fichier, mais ce n’est parfois pas assez fiable. Une méthode d’interrogation simple des changements de taille de fichier est utilisée ci-dessous dans outputReadThread si OutputCallback n’est pas null.

Voici un appel à ExecuteProcess avec rappel pour recevoir immédiatement la sortie du processus.

  public static void ResizeTiff(ssortingng SourceFile, ssortingng DestinationFile, float ResolutionWidth, float ResolutionHeight, Guid ProcessId) { var directory = GDalBin; var exe = Path.Combine(directory, "gdalwarp.exe"); var args = " -ts " + ResolutionWidth + " " + ResolutionHeight + " -r cubic -co \"TFW=YES\" \"" + SourceFile + "\" \"" + DestinationFile + "\""; float progress = 0; Action callback = delegate(ssortingng fullOutput, ssortingng newOutput) { float value; if (float.TryParse(newOutput, out value)) progress = value; else if (newOutput == ".") progress += 2.5f; else if (newOutput.StartsWith("100")) progress = 100; }; ExecuteProcess(exe, args, null, directory, 0, null, true, true, 0, callback); } 

Voici une fonction permettant d’appeler n’importe quel processus et de recevoir les résultats au fur et à mesure.

  public static ssortingng ExecuteProcess(ssortingng FilePath, ssortingng Args, ssortingng Input, ssortingng WorkingDir, int WaitTime = 0, Dictionary EnviroVariables = null, bool Trace = false, bool ThrowError = true, int ValidExitCode = 0, Action OutputChangedCallback = null) { var processInfo = "FilePath: " + FilePath + "\n" + (WaitTime > 0 ? "WaitTime: " + WaitTime.ToSsortingng() + " ms\n" : "") + (!ssortingng.IsNullOrEmpty(Args) ? "Args: " + Args + "\n" : "") + (!ssortingng.IsNullOrEmpty(Input) ? "Input: " + Input + "\n" : "") + (!ssortingng.IsNullOrEmpty(WorkingDir) ? "WorkingDir: " + WorkingDir + "\n" : "") + (EnviroVariables != null && EnviroVariables.Count > 0 ? "Environment Variables: " + ssortingng.Join(", ", EnviroVariables.Select(a => a.Key + "=" + a.Value)) + "\n" : ""); ssortingng outputFile = ""; if (OutputChangedCallback != null) { outputFile = Path.GetTempFileName(); Args = "/C \"\"" + FilePath + "\" " + Args + "\" >" + outputFile; FilePath = "cmd.exe"; } var startInfo = (ssortingng.IsNullOrEmpty(Args)) ? new ProcessStartInfo(FilePath) : new ProcessStartInfo(FilePath, Args); if (!ssortingng.IsNullOrEmpty(WorkingDir)) startInfo.WorkingDirectory = WorkingDir; startInfo.UseShellExecute = false; startInfo.CreateNoWindow = true; if (OutputChangedCallback == null) { startInfo.RedirectStandardOutput = true; startInfo.RedirectStandardError = true; } else { startInfo.RedirectStandardOutput = false; startInfo.RedirectStandardError = false; } if (!ssortingng.IsNullOrEmpty(Input)) startInfo.RedirectStandardInput = true; if (EnviroVariables != null) foreach (KeyValuePair entry in EnviroVariables) startInfo.EnvironmentVariables.Add(entry.Key, entry.Value); var process = new Process(); process.StartInfo = startInfo; if (process.Start()) { if (Trace) Log.Debug("Running external process with the following parameters:\n" + processInfo); try { if (!ssortingng.IsNullOrEmpty(Input)) { process.StandardInput.Write(Input); process.StandardInput.Close(); } var standardError = ""; var standardOutput = ""; int exitCode = 0; Thread errorReadThread; Thread outputReadThread; if (OutputChangedCallback == null) { errorReadThread = new Thread(new ThreadStart(() => { standardError = process.StandardError.ReadToEnd(); })); outputReadThread = new Thread(new ThreadStart(() => { standardOutput = process.StandardOutput.ReadToEnd(); })); } else { errorReadThread = new Thread(new ThreadStart(() => { })); outputReadThread = new Thread(new ThreadStart(() => { long len = 0; while (!process.HasExited) { if (File.Exists(outputFile)) { var info = new FileInfo(outputFile); if (info.Length != len) { var content = new StreamReader(File.Open(outputFile, FileMode.Open, FileAccess.Read, FileShare.ReadWrite)).ReadToEnd(); var newContent = content.Subssortingng((int)len, (int)(info.Length - len)); len = info.Length; OutputChangedCallback.Invoke(content, newContent); } } Thread.Sleep(10); } })); } errorReadThread.Start(); outputReadThread.Start(); var sw = Stopwatch.StartNew(); bool timedOut = false; try { while (errorReadThread.IsAlive || outputReadThread.IsAlive) { Thread.Sleep(50); if (WaitTime > 0 && sw.ElapsedMilliseconds > WaitTime) { if (errorReadThread.IsAlive) errorReadThread.Abort(); if (outputReadThread.IsAlive) outputReadThread.Abort(); timedOut = true; break; } } if (!process.HasExited) process.Kill(); if (timedOut) throw new TimeoutException("Timeout occurred during execution of an external process.\n" + processInfo + "Standard Output: " + standardOutput + "\nStandard Error: " + standardError); exitCode = process.ExitCode; } finally { sw.Stop(); process.Close(); process.Dispose(); } if (ThrowError && exitCode != ValidExitCode) throw new Exception("An error was returned from the execution of an external process.\n" + processInfo + "Exit Code: " + exitCode + "\nStandard Output: " + standardOutput + "\nStandard Error: " + standardError); if (Trace) Log.Debug("Process Exited with the following values:\nExit Code: {0}\nStandard Output: {1}\nStandard Error: {2}", exitCode, standardOutput, standardError); return standardOutput; } finally { FileUtilities.AttemptToDeleteFiles(new ssortingng[] { outputFile }); } } else throw new Exception("The process failed to start.\n" + processInfo); }