如何让 ffmpeg 在 try/catch 上为工作目录和参数抛出异常？

Question

例如，如果我将 FileName(outputDirectory) 设置为 null，它将引发异常。

我使用 ffmpeg.exe 进程时的类：

public void Start()
        {
            process = new Process();
            process.StartInfo.FileName = outputDirectory; // Change the directory where ffmpeg.exe is.  
            process.EnableRaisingEvents = false;
            process.StartInfo.WorkingDirectory = workingDirectory; // The output directory  
            process.StartInfo.Arguments = arguments;
            process.StartInfo.UseShellExecute = false;
            process.StartInfo.RedirectStandardInput = true; //Redirect stdin
            process.StartInfo.CreateNoWindow = true;
            process.Start();

            errorMessage = false;
            startRecord = true;
        }

但是如果我将 WorkingDirectory 设置为 null 或输入一些无效的参数，如“sadasdasd”，它不会在 WorkingDirectory 和参数上抛出异常。

在 Form1 中：

private void recordStripMenuItem_Click(object sender, EventArgs e)
        {
            recordToggle = !recordToggle;

            if (recordToggle)
            {
                try
                {
                    record.workingDirectory = settingsForm.workingDirectory;
                    record.outputDirectory = settingsForm.outputDirectory;
                    record.arguments = settingsForm.arguments;
                    record.Start();
                }
                catch(Exception ex)
                {
                    recordStripMenuItem.Text = "Record";
                    Icon = iconGreen;
                    TextInfo("Waiting");
                    recordToggle = false;
                    MessageBox.Show("Arguments are not valid : " + ex.Message);
                    
                }
                if (!FFmpeg_Capture.errorMessage)
                {
                    settingsForm.Close();
                    recordStripMenuItem.Text = "Stop";
                    Icon = iconRed;
                    TextInfo("Recording");
                }
            }
            else
            {
                recordStripMenuItem.Text = "Record";
                Icon = iconGreen;
                TextInfo("Waiting");
                record.Stop();
            }
        }

变量record是FFmpeg_Capture类的实例，带有ffmpeg的进程。 它仅在 FileName(outputDirectory) 上引发异常。

Answer 1

在您的 start() 方法中添加以下代码，如果工作目录不存在则抛出异常：

public void Start(){
    if(!System.IO.Directory.Exists(this.workingDirectory){
        throw new Exception("workingDirectory doesn't exist");
    }
    
    //.. the rest of the code
    
}