这篇文章相对于以往的文章，会过于难懂些，主要原因是涉及到了Windows开发，我想我们大部分的小伙伴也没有真正的接触过Windows开发，所以会导致对于调度Windows API时一些结构体变量和动态库函数的动态调用，产生陌生感甚至是一头雾水，当然这些是可以通过学习去弥补的。
阅读文章的小伙伴不需要担心，代码层次已经分离了。对于想要直接使用的直接去看已经封装好的调用函数即可 (函数名：
AddCustomPaperSize) 相关的注释也都注解了。
下面归结下代码：
整个代码分为两大块：①Windows API 及相关的结构体变量；②封装的调用函数。
关于 Windows API 可以去看 打印机驱动程序设计指南 相关的文档，就不过多赘述了。
调用函数封装这块：
这里需要注意的是，我写的类是个非静态类，并且写了构造函数，但是我的封装函数是个静态的。这里给大家做一个解释，我是有尝试过写静态类的，但是写静态类我们都知道在C#中静态类是没有构造函数的，这样在调用 Windows API 时会出现调用成功但是我们所设定的值并没有被写入，这个不是 bug 哦，这是一个调度机制的问题 (这里也不做解释有兴趣的可以自行了解) 。这里的做法就是使用 实例类＋构造函数＋静态方法 的形式便于我们的使用。
就不多说了，代码里面的注释比较的详细
using System;
using System.Runtime.InteropServices;
using System.Security;
using System.Text;
namespace CustomPaperSize
{
public class CustomPaperSize
{
#region WindowsAPI
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
internal struct StructPrinterDefaults
{
[MarshalAs(UnmanagedType.LPTStr)]
public String pDatatype;
public IntPtr pDevMode;
[MarshalAs(UnmanagedType.I4)]
public int DesiredAccess;
};
[DllImport("winspool.Drv", EntryPoint = "OpenPrinter", SetLastError = true, CharSet = CharSet.Unicode, ExactSpelling = false,
CallingConvention = CallingConvention.StdCall), SuppressUnmanagedCodeSecurityAttribute()]
internal static extern bool OpenPrinter(
[MarshalAs(UnmanagedType.LPTStr)] string printerName,
out IntPtr phPrinter,
ref StructPrinterDefaults pd);
[DllImport("winspool.Drv", EntryPoint = "ClosePrinter", SetLastError = true, CharSet = CharSet.Unicode, ExactSpelling = false,
CallingConvention = CallingConvention.StdCall), SuppressUnmanagedCodeSecurityAttribute()]
internal static extern bool ClosePrinter(IntPtr phPrinter);
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
internal struct StructSize
{
public Int32 width;
public Int32 height;
}
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
internal struct StructRect
{
public Int32 left;
public Int32 top;
public Int32 right;
public Int32 bottom;
}
[StructLayout(LayoutKind.Explicit, CharSet = CharSet.Unicode)]
internal struct FormInfo1
{
[FieldOffset(0), MarshalAs(UnmanagedType.I4)] public uint Flags;
[FieldOffset(4), MarshalAs(UnmanagedType.LPWStr)] public String pName;
[FieldOffset(8)] public StructSize Size;
[FieldOffset(16)] public StructRect ImageableArea;
};
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi/* changed from CharSet=CharSet.Auto */)]
internal struct StructDevMode
{
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 32)] public String dmDeviceName;
[MarshalAs(UnmanagedType.U2)] public short dmSpecVersion;
[MarshalAs(UnmanagedType.U2)] public short dmDriverVersion;
[MarshalAs(UnmanagedType.U2)] public short dmSize;
[MarshalAs(UnmanagedType.U2)] public short dmDriverExtra;
[MarshalAs(UnmanagedType.U4)] public int dmFields;
[MarshalAs(UnmanagedType.I2)] public short dmOrientation;
[MarshalAs(UnmanagedType.I2)] public short dmPaperSize;
[MarshalAs(UnmanagedType.I2)] public short dmPaperLength;
[MarshalAs(UnmanagedType.I2)] public short dmPaperWidth;
[MarshalAs(UnmanagedType.I2)] public short dmScale;
[MarshalAs(UnmanagedType.I2)] public short dmCopies;
[MarshalAs(UnmanagedType.I2)] public short dmDefaultSource;
[MarshalAs(UnmanagedType.I2)] public short dmPrintQuality;
[MarshalAs(UnmanagedType.I2)] public short dmColor;
[MarshalAs(UnmanagedType.I2)] public short dmDuplex;
[MarshalAs(UnmanagedType.I2)] public short dmYResolution;
[MarshalAs(UnmanagedType.I2)] public short dmTTOption;
[MarshalAs(UnmanagedType.I2)] public short dmCollate;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 32)] public String dmFormName;
[MarshalAs(UnmanagedType.U2)] public short dmLogPixels;
[MarshalAs(UnmanagedType.U4)] public int dmBitsPerPel;
[MarshalAs(UnmanagedType.U4)] public int dmPelsWidth;
[MarshalAs(UnmanagedType.U4)] public int dmPelsHeight;
[MarshalAs(UnmanagedType.U4)] public int dmNup;
[MarshalAs(UnmanagedType.U4)] public int dmDisplayFrequency;
[MarshalAs(UnmanagedType.U4)] public int dmICMMethod;
[MarshalAs(UnmanagedType.U4)] public int dmICMIntent;
[MarshalAs(UnmanagedType.U4)] public int dmMediaType;
[MarshalAs(UnmanagedType.U4)] public int dmDitherType;
[MarshalAs(UnmanagedType.U4)] public int dmReserved1;
[MarshalAs(UnmanagedType.U4)] public int dmReserved2;
}
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
internal struct PRINTER_INFO_9
{
public IntPtr pDevMode;
}
[DllImport("winspool.Drv", EntryPoint = "AddFormW", SetLastError = true, CharSet = CharSet.Unicode, ExactSpelling = true,
CallingConvention = CallingConvention.StdCall), SuppressUnmanagedCodeSecurityAttribute()]
internal static extern bool AddForm(IntPtr phPrinter, [MarshalAs(UnmanagedType.I4)] int level, ref FormInfo1 form);
/* This method is not used
[DllImport("winspool.Drv", EntryPoint="SetForm", SetLastError=true,
CharSet=CharSet.Unicode, ExactSpelling=false,
CallingConvention=CallingConvention.StdCall), SuppressUnmanagedCodeSecurityAttribute()]
internal static extern bool SetForm(IntPtr phPrinter, string paperName,
[MarshalAs(UnmanagedType.I4)] int level, ref FormInfo1 form);
*/
[DllImport("winspool.Drv", EntryPoint = "DeleteForm", SetLastError = true, CharSet = CharSet.Unicode, ExactSpelling = false,
CallingConvention = CallingConvention.StdCall), SuppressUnmanagedCodeSecurityAttribute()]
internal static extern bool DeleteForm(IntPtr phPrinter, [MarshalAs(UnmanagedType.LPTStr)] string pName);
[DllImport("kernel32.dll", EntryPoint = "GetLastError", SetLastError = false, ExactSpelling = true,
CallingConvention = CallingConvention.StdCall),
SuppressUnmanagedCodeSecurityAttribute()]
internal static extern Int32 GetLastError();
[DllImport("GDI32.dll", EntryPoint = "CreateDC", SetLastError = true, CharSet = CharSet.Unicode, ExactSpelling = false,
CallingConvention = CallingConvention.StdCall),
SuppressUnmanagedCodeSecurityAttribute()]
internal static extern IntPtr CreateDC([MarshalAs(UnmanagedType.LPTStr)] string pDrive, [MarshalAs(UnmanagedType.LPTStr)]
string pName, [MarshalAs(UnmanagedType.LPTStr)] string pOutput, ref StructDevMode pDevMode);
[DllImport("GDI32.dll", EntryPoint = "ResetDC", SetLastError = true, CharSet = CharSet.Unicode, ExactSpelling = false,
CallingConvention = CallingConvention.StdCall), SuppressUnmanagedCodeSecurityAttribute()]
internal static extern IntPtr ResetDC(IntPtr hDC, ref StructDevMode pDevMode);
[DllImport("GDI32.dll", EntryPoint = "DeleteDC", SetLastError = true, CharSet = CharSet.Unicode, ExactSpelling = false,
CallingConvention = CallingConvention.StdCall), SuppressUnmanagedCodeSecurityAttribute()]
internal static extern bool DeleteDC(IntPtr hDC);
[DllImport("winspool.Drv", EntryPoint = "SetPrinterA", SetLastError = true, CharSet = CharSet.Auto, ExactSpelling = true,
CallingConvention = CallingConvention.StdCall), SuppressUnmanagedCodeSecurityAttribute()]
internal static extern bool SetPrinter(
IntPtr hPrinter,
[MarshalAs(UnmanagedType.I4)] int level,
IntPtr pPrinter, [MarshalAs(UnmanagedType.I4)]
int command);
/*
LONG DocumentProperties(
HWND hWnd, // handle to parent window
HANDLE hPrinter, // handle to printer object
LPTSTR pDeviceName, // device name
PDEVMODE pDevModeOutput, // modified device mode
PDEVMODE pDevModeInput, // original device mode
DWORD fMode // mode options
);
*/
[DllImport("winspool.Drv", EntryPoint = "DocumentPropertiesA", SetLastError = true, ExactSpelling = true,
CallingConvention = CallingConvention.StdCall)]
public static extern int DocumentProperties(
IntPtr hwnd,
IntPtr hPrinter,
[MarshalAs(UnmanagedType.LPStr)] string pDeviceName /* changed from String to string */,
IntPtr pDevModeOutput,
IntPtr pDevModeInput,
int fMode
);
[DllImport("winspool.Drv", EntryPoint = "GetPrinterA", SetLastError = true,
ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
public static extern bool GetPrinter(
IntPtr hPrinter,
int dwLevel /* changed type from Int32 */,
IntPtr pPrinter,
int dwBuf /* chagned from Int32*/,
out int dwNeeded /* changed from Int32*/
);
// SendMessageTimeout tools
[Flags]
public enum SendMessageTimeoutFlags : uint
{
SMTO_NORMAL = 0x0000,
SMTO_BLOCK = 0x0001,
SMTO_ABORTIFHUNG = 0x0002,
SMTO_NOTIMEOUTIFNOTHUNG = 0x0008
}
const int WM_SETTINGCHANGE = 0x001A;
const int HWND_BROADCAST = 0xffff;
[DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]
public static extern IntPtr SendMessageTimeout(
IntPtr windowHandle,
uint Msg,
IntPtr wParam,
IntPtr lParam,
SendMessageTimeoutFlags flags,
uint timeout,
out IntPtr result
);
#endregion
public CustomPaperSize() { }
/// 写文章与大家一起交流学习，如果有大佬看到了觉得还可以进行优化，望不吝赐教。