C#winform 调用python程序，如何接收python函数返回的中文字符

python程序如下（文件名为Obtain.py）：
def test(strinfo):
a = "求助帖："
b = a + strinfo
return b

C#中的代码如下（这是一个界面程序）：
namespace getinfo

{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

    void Obtain_Click(object sender, EventArgs e)
    {
        var result = "";
        var engine = IronPython.Hosting.Python.CreateEngine();
        var scope = engine.CreateScope();
        var source = engine.CreateScriptSourceFromFile("Obtain.py");
        source.Execute(scope);
        var test = scope.GetVariable<Func<object, object>>("test");
                    result = (string)test("please help me!\n");
                    AppendLine(result);
    }
            public void AppendLine(string s)
    {
        if (output.Lines.Count() >= 20)
            output.Text = string.Join("\r\n", output.Lines.Skip(1));
        output.Text += s;
        output.SelectionStart = output.TextLength;
        output.Focus();
    }
    }

}

我想把收到的那个包含中英文的字符串输出到richtextbox上，但是显示的结果一直是乱码？求大神指点。。

http://outofmemory.cn/code-snippet/1587/python-zhongwen-charaeter-coding-decode-encode-yiji-luanma-resolve-summary

要设置下编码格式，转化成UTF-8