的KeyDown键转换为一个字符串中的C＃ [英] Convert KeyDown keys to one string C#

问题描述

我有磁卡读写器，它模拟键盘打字时，用户刷卡卡。我需要处理这个键盘打字一个字符串，当我的WPF窗口被聚焦。我能得到这个类型的重点名单，但我不知道如何将它们转换成一串。

I have magnetic card reader, It emulates Keyboard typing when user swipes card. I need to handle this keyboard typing to one string, when my WPF window is Focused. I can get this typed Key list, but I don't know how to convert them to one string.

private void Window_KeyDown(object sender, KeyEventArgs e)
{
   list.Add(e.Key);
}

修改：简单的ToString（）方法，不是帮助。我已经尝试过这一点。

EDIT: Simple .ToString() method not helps. I've tried this already.

推荐答案

而不是增加一个列表为什么不建立字符串：

Rather than adding to a list why not build up the string:

private string input;

private bool shiftPressed;

private void Window_KeyDown(object sender, KeyEventArgs e)
{
    if (e.Key == Key.LeftShift || e.Key == Key.RightShift)
    {
        shiftPressed = true;
    }
    else
    {
        if (e.Key >= Key.D0 && e.Key <= Key.D9)
        {
            // Number keys pressed so need to so special processing
            // also check if shift pressed
        }
        else
        {
            input += e.Key.ToString();
        }
    }
}

private void Window_KeyUp(object sender, KeyEventArgs e)
{
    if (e.Key == Key.LeftShift || e.Key == Key.RightShift)
    {
        shiftPressed = false;
    }
}

显然，你需要重新设置输入到的String.Empty 当你开始下一个事务。

Obviously you need to reset input to string.Empty when you start the next transaction.

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