Question

我正在尝试将越南语转换为拉丁语。要求将字节发送到ESC / P打印机（原因请参见C# ESC/POS Print Vietnamese）。

但是我的问题很简单，请看下面的代码：

Encoding enc = Encoding.GetEncoding(1258); //vietnamese code page
string content = "Cơm chiên với các loại gia vị truyền";
string newStr = Encoding.GetEncoding("Latin1").GetString(enc.GetBytes(content));
string origStr = enc.GetString(Encoding.GetEncoding("Latin1").GetBytes(newStr)); //origStr is becomes "Cơm chiên v?i các lo?i gia v? truy?n"

为什么origStr变成Cơm chiên v?i các lo?i gia v? truy?n而不是包含与content相同的内容？但是，它工作可以用中文或泰语很好地工作。您可以在下面测试代码...

简体中文

Encoding enc = Encoding.GetEncoding(936); //chinese simplified code page
string content = "印尼炒饭";
string newStr = Encoding.GetEncoding("Latin1").GetString(enc.GetBytes(content));
string origStr = enc.GetString(Encoding.GetEncoding("Latin1").GetBytes(newStr)); //origStr is correct "印尼炒饭"

泰语

Encoding enc = Encoding.GetEncoding(874); //Thai code page
string content = "ข้าวผัดอินโดนีเซียกับเครื่องเทศแบบดั้ง";
string newStr = Encoding.GetEncoding("Latin1").GetString(enc.GetBytes(content));
string origStr = enc.GetString(Encoding.GetEncoding("Latin1").GetBytes(newStr)); //origStr is correct "ข้าวผัดอินโดนีเซียกับเครื่องเทศแบบดั้ง"

知道为什么吗？为什么越南人不工作？如何使其起作用，以便可以将其发送到打印机？

感谢您的帮助：）

PS。这是我用来发送给打印机的代码

[DllImport("Winspool.drv", EntryPoint = "ClosePrinter", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
public static extern bool ClosePrinter(IntPtr hPrinter);

[DllImport("Winspool.drv", EntryPoint = "EndDocPrinter", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
public static extern bool EndDocPrinter(IntPtr hPrinter);

[DllImport("Winspool.drv", EntryPoint = "EndPagePrinter", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
public static extern bool EndPagePrinter(IntPtr hPrinter);

[DllImport("Winspool.drv", EntryPoint = "OpenPrinterA", SetLastError = true, CharSet = CharSet.Ansi, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
public static extern bool OpenPrinter([MarshalAs(UnmanagedType.LPStr)] string szPrinter, out IntPtr hPrinter, IntPtr pd);

[DllImport("Winspool.drv", EntryPoint = "StartDocPrinterA", SetLastError = true, CharSet = CharSet.Ansi, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
public static extern bool StartDocPrinter(IntPtr hPrinter, Int32 level, [In, MarshalAs(UnmanagedType.LPStruct)] DOCINFOA di);

[DllImport("Winspool.drv", EntryPoint = "StartPagePrinter", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
public static extern bool StartPagePrinter(IntPtr hPrinter);

[DllImport("Winspool.drv", EntryPoint = "WritePrinter", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
public static extern bool WritePrinter(IntPtr hPrinter, IntPtr pBytes, Int32 dwCount, out Int32 dwWritten);

public static bool SendBytesToPrinter(string printerName, IntPtr pBytes, int dwCount, string docName = null, string dataType = "RAW")
{
    DOCINFOA di = new DOCINFOA();
    di.pDocName = string.IsNullOrWhiteSpace(docName) ? string.Empty : docName;
    di.pDataType = string.IsNullOrWhiteSpace(dataType) ? "RAW" : dataType;

    IntPtr hPrinter = new IntPtr(0); int dwError = 0, dwWritten = 0; bool bSuccess = false;
    if (OpenPrinter(printerName.Normalize(), out hPrinter, IntPtr.Zero))
    {
        if (StartDocPrinter(hPrinter, 1, di))
        {
            if (StartPagePrinter(hPrinter))
            {
                bSuccess = WritePrinter(hPrinter, pBytes, dwCount, out dwWritten);
                EndPagePrinter(hPrinter);
            }
            EndDocPrinter(hPrinter);
        }
        ClosePrinter(hPrinter);
    }

    if (bSuccess == false)
        dwError = Marshal.GetLastWin32Error();
    return bSuccess;
}

public static bool SendBytesToPrinter(string printerName, byte[] bytes, string docName)
{
    int dwCount = bytes.Length;
    IntPtr ptrBytes = Marshal.AllocCoTaskMem(Marshal.SizeOf(typeof(byte)) * bytes.Length);
    try
    {
        Marshal.Copy(bytes, 0, ptrBytes, bytes.Length);
        SendBytesToPrinter(printerName, ptrBytes, dwCount, docName);
    }
    finally { Marshal.FreeCoTaskMem(ptrBytes); }
    return true;
}

public static bool SendStringToPrinter(string printerName, string str, string docName)
{
    int dwCount = str.Length;
    IntPtr ptrBytes = Marshal.StringToCoTaskMemAnsi(str);
    try { SendBytesToPrinter(printerName, ptrBytes, dwCount, docName); }
    finally { Marshal.FreeCoTaskMem(ptrBytes); }
    return true;
}

Answer 1

通常，当您向编码器提供代码页中不存在的数据时，就会发生这种情况。

因此，如果您愿意尝试转换一个字节值大于255的字符（在codepage 1258中不存在），在这种情况下，您会得到一个回退字符，即?字符。我的猜测是，在第一种情况下，输入字符串中的数据无效（也许看起来相同但不是正确的字符）。

下一步是检查字符及其对应的字节值。

将文本转换为拉丁语编码并为越南语解码回问题

1 个答案: