c# - 某些 Python 命令未在 Stdout 中捕获

Question

我编写了一个简单的程序来捕获并执行命令行 Python 脚本，但有一个问题。尽管我的程序捕获了标准输出，但传递给 Python 输入函数的文本并未写入我的程序。

例如:Python 脚本:

import sys

print("Hello, World!")
x = input("Please enter a number: ")
print(x)

print("This work?")

会写“你好，世界!”然后停下来。当我向它传递一个数字时，它会继续写“请输入数字:3”。到底是怎么回事？有什么解决办法吗？我的 C# 如下:

public partial class PyCon : Window
{
        public string strPythonPath;
        public string strFile;
        public string strArguments;
        private StreamWriter sw;

        public PyCon(string pythonpath, string file, string args)
        {
            strPythonPath = pythonpath;
            strFile = file;
            strArguments = args;

            InitializeComponent();

            Process p = new Process();

            p.StartInfo.FileName = strPythonPath;
            p.StartInfo.Arguments = "\"" + strFile + "\" " + strArguments;

            p.StartInfo.UseShellExecute = false;
            p.StartInfo.CreateNoWindow = true;

            p.StartInfo.RedirectStandardInput = true;
            p.StartInfo.RedirectStandardOutput = true;
            p.StartInfo.RedirectStandardError = true;

            p.OutputDataReceived += new DataReceivedEventHandler(p_OutputDataReceived);
            p.ErrorDataReceived += new DataReceivedEventHandler(p_ErrorDataReceived);

            p.Start();
            p.BeginOutputReadLine();
            p.BeginErrorReadLine();
            sw = p.StandardInput;
        }

        private void p_OutputDataReceived(object sendingProcess, DataReceivedEventArgs received) {
            if (!String.IsNullOrEmpty(received.Data)) {
                AppendConsole(received.Data);
            }
        }

        private void p_ErrorDataReceived(object sendingProcess, DataReceivedEventArgs received) {
            if (!String.IsNullOrEmpty(received.Data)) {
                AppendConsole(received.Data);
            }
        }

        private void AppendConsole(string message) {
            if (!txtConsole.Dispatcher.CheckAccess()) {
                txtConsole.Dispatcher.Invoke(DispatcherPriority.Normal, (System.Windows.Forms.MethodInvoker)delegate() { txtConsole.AppendText(message + "\n"); });
            } else {
                //Format text
                message = message.Replace("\n", Environment.NewLine);

                txtConsole.AppendText(message + "\n");   
            }
        }

        private void txtInput_KeyUp(object sender, KeyEventArgs e) {
            if (e.Key != Key.Enter) return;

            sw.WriteLine(txtInput.Text);

            txtInput.Text = "";


        }
    }

编辑:经过此线程的大量研究和帮助，我得出的结论是，问题在于 Python 输入命令未调用 C# DataReceivedEventHandler。除了更改脚本之外，可能没有其他解决方案。如果是这种情况，我将做出包含已接受的更改的答案。谢谢你们的帮助，伙计们!

Answer 1

听起来像 Python i/o 是行缓冲的，即等待 CRLF 然后立即发送整行。您可以尝试将其关闭(python -u myscript.py，或设置PYTHONUNBUFFERED环境变量)或使用以下方法解决它:

print("Hello, World!")
print("Please enter a number: ")
x = input()
print(x)