client/Helpers/WindowsPrintApi.cs

using System.Runtime.InteropServices;

namespace CloudPrint.Client.Helpers;

/// <summary>
/// Windows Print Spooler API P/Invoke 声明，用于 RAW 打印、队列枚举和任务取消。
/// </summary>
public static class WindowsPrintApi
{
    public const int JobControlCancel = 3;
    public const int JobControlDelete = 5;

    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
    public sealed class DocInfo
    {
        [MarshalAs(UnmanagedType.LPWStr)]
        public string DocumentName = string.Empty;

        [MarshalAs(UnmanagedType.LPWStr)]
        public string? OutputFile;

        [MarshalAs(UnmanagedType.LPWStr)]
        public string DataType = "RAW";
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct SystemTime
    {
        public short Year;
        public short Month;
        public short DayOfWeek;
        public short Day;
        public short Hour;
        public short Minute;
        public short Second;
        public short Milliseconds;
    }

    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
    public struct JobInfo1
    {
        public int JobId;

        [MarshalAs(UnmanagedType.LPWStr)]
        public string? PrinterName;

        [MarshalAs(UnmanagedType.LPWStr)]
        public string? MachineName;

        [MarshalAs(UnmanagedType.LPWStr)]
        public string? UserName;

        [MarshalAs(UnmanagedType.LPWStr)]
        public string? DocumentName;

        [MarshalAs(UnmanagedType.LPWStr)]
        public string? DataType;

        [MarshalAs(UnmanagedType.LPWStr)]
        public string? StatusText;

        public int Status;
        public int Priority;
        public int Position;
        public int TotalPages;
        public int PagesPrinted;
        public SystemTime Submitted;
    }

    [DllImport("winspool.drv", EntryPoint = "OpenPrinterW", SetLastError = true, CharSet = CharSet.Unicode)]
    [return: MarshalAs(UnmanagedType.Bool)]
    public static extern bool OpenPrinter(string printerName, out IntPtr printerHandle, IntPtr printerDefaults);

    [DllImport("winspool.drv", EntryPoint = "ClosePrinter", SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    public static extern bool ClosePrinter(IntPtr printerHandle);

    [DllImport("winspool.drv", EntryPoint = "StartDocPrinterW", SetLastError = true, CharSet = CharSet.Unicode)]
    public static extern int StartDocPrinter(IntPtr printerHandle, int level, [In] DocInfo documentInfo);

    [DllImport("winspool.drv", EntryPoint = "EndDocPrinter", SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    public static extern bool EndDocPrinter(IntPtr printerHandle);

    [DllImport("winspool.drv", EntryPoint = "StartPagePrinter", SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    public static extern bool StartPagePrinter(IntPtr printerHandle);

    [DllImport("winspool.drv", EntryPoint = "EndPagePrinter", SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    public static extern bool EndPagePrinter(IntPtr printerHandle);

    [DllImport("winspool.drv", EntryPoint = "WritePrinter", SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    public static extern bool WritePrinter(IntPtr printerHandle, byte[] data, int count, out int written);

    [DllImport("winspool.drv", EntryPoint = "EnumJobsW", SetLastError = true, CharSet = CharSet.Unicode)]
    [return: MarshalAs(UnmanagedType.Bool)]
    public static extern bool EnumJobs(
        IntPtr printerHandle,
        int firstJob,
        int numberOfJobs,
        int level,
        IntPtr jobBuffer,
        int bufferSize,
        out int bytesNeeded,
        out int jobsReturned);

    [DllImport("winspool.drv", EntryPoint = "SetJobW", SetLastError = true, CharSet = CharSet.Unicode)]
    [return: MarshalAs(UnmanagedType.Bool)]
    public static extern bool SetJob(
        IntPtr printerHandle,
        int jobId,
        int level,
        IntPtr jobInfo,
        int command);
}