private static DC_PAPER_SIZE[] ReadDC_PAPER_SIZEArray(HGlobalBuffer buffer, int itemByteSize)
{
int nItems = buffer.Length / itemByteSize;
DC_PAPER_SIZE[] result = new DC_PAPER_SIZE[nItems];
bool shouldRelease = false;
buffer.Handle.DangerousAddRef(ref shouldRelease);
try
{
IntPtr baseAddr = buffer.Handle.DangerousGetHandle();
for (int i = 0, offset = 0; i < nItems; i++, offset += itemByteSize)
{
int w = Marshal.ReadInt32(baseAddr, offset);
int h = Marshal.ReadInt32(baseAddr, offset + (itemByteSize / 2));
result[i] = new DC_PAPER_SIZE(w, h);
}
return(result);
}
finally
{
if (shouldRelease)
{
buffer.Handle.DangerousRelease();
}
}
}
private short[] ReadWORDArray(HGlobalBuffer buffer, int itemByteSize)
{
int nItems = buffer.Length / itemByteSize;
short[] result = new short[nItems];
bool shouldRelease = false;
buffer.Handle.DangerousAddRef(ref shouldRelease);
try
{
IntPtr baseAddr = buffer.Handle.DangerousGetHandle();
for (int i = 0, offset = 0; i < nItems; i++, offset += itemByteSize)
{
result[i] = Marshal.ReadInt16(baseAddr, offset);
}
return(result);
}
finally
{
if (shouldRelease)
{
buffer.Handle.DangerousRelease();
}
}
}
/// <summary>
/// Gets a device capability represented as an array
/// </summary>
/// <param name="capability">Capability to retrieve</param>
/// <returns>value of capability specified in capability argument</returns>
private T[] GetArrayCapability <T>(DeviceCapability capability, ReadArray <T> readArray, int itemByteSize)
{
uint numOutputs = UnsafeNativeMethods.DeviceCapabilitiesW(this._deviceName, this._portName, capability, SafeMemoryHandle.Null, this._devMode);
if (numOutputs < 1)
{
return(Array.Empty <T>());
}
HGlobalBuffer buffer = new HGlobalBuffer((int)(numOutputs * itemByteSize));
try
{
numOutputs = UnsafeNativeMethods.DeviceCapabilitiesW(this._deviceName, this._portName, capability, buffer.Handle, this._devMode);
if (numOutputs >= 0)
{
return(readArray(buffer, itemByteSize));
}
}
finally
{
buffer.Release();
}
return(null);
}
private static string [] ReadUnicodeStringArray(HGlobalBuffer buffer, int itemByteSize)
{
int nItems = buffer.Length / itemByteSize;
string[] result = new string[nItems];
bool shouldRelease = false;
buffer.Handle.DangerousAddRef(ref shouldRelease);
try
{
IntPtr baseAddr = buffer.Handle.DangerousGetHandle();
for (int i = 0, offset = 0; i < nItems; i++, offset += itemByteSize)
{
IntPtr strAddr = new IntPtr(baseAddr.ToInt64() + offset);
string str = Marshal.PtrToStringUni(strAddr, itemByteSize / 2);
//Marshal.PtrToStringUni(IntPtr) Copies until '/0'
//Marshal.PtrToStringUni(IntPtr, int len) Copies all characters in the string including any '\0'
// What we want is to copy until '/0' but no more than len chars
int index = str.IndexOf('\0');
if (index >= 0)
{
str = str.Substring(0, index);
}
result[i] = str;
}
return(result);
}
finally
{
if (shouldRelease)
{
buffer.Handle.DangerousRelease();
}
}
}
/// <summary>
/// A callback that copies PRINTER_INFO_8_AND_9 fields from an unmanaged buffer
/// </summary>
public void Callback(HGlobalBuffer pPrinterBuffer)
{
// PRINTER_INFO_8 layout from http://msdn.microsoft.com/en-us/library/dd162851(VS.85).aspx
//
// typedef struct _PRINTER_INFO_8 {
// LPDEVMODE pDevMode;
// } PRINTER_INFO_8, *PPRINTER_INFO_8;
//
// PRINTER_INFO_9 layout from http://msdn.microsoft.com/en-us/library/dd162852(VS.85).aspx
//
// typedef struct _PRINTER_INFO_9 {
// LPDEVMODE pDevMode;
// } PRINTER_INFO_9, *PPRINTER_INFO_9;
// LPDEVMODE pDevMode;
PRINTER_INFO_8_AND_9 = new PRINTER_INFO_8_AND_9();
bool shouldRelease = false;
pPrinterBuffer.Handle.DangerousAddRef(ref shouldRelease);
try
{
IntPtr pDevMode = Marshal.ReadIntPtr(pPrinterBuffer.Handle.DangerousGetHandle());
if (pDevMode != IntPtr.Zero)
{
PRINTER_INFO_8_AND_9.pDevMode = DevMode.FromIntPtr(pDevMode);
}
}
finally
{
if (shouldRelease)
{
pPrinterBuffer.Handle.DangerousRelease();
}
}
}
///<summary>
/// Executes an action delegate on an unmanaged buffer representing printer information
///</summary>
///<param name="dwLevel">Level of printer information to process</param>
///<param name="action">Delegate that processes printer information</param>
///<returns>False if tha call fails</returns>
private bool GetPrinterW(uint dwLevel, Action <HGlobalBuffer> action)
{
uint dwNeeded = 0;
UnsafeNativeMethods.GetPrinterW(this._deviceHandle, dwLevel, SafeMemoryHandle.Null, dwNeeded, ref dwNeeded);
if (dwNeeded > 0)
{
HGlobalBuffer pPrinterBuffer = new HGlobalBuffer((int)dwNeeded);
try
{
if (UnsafeNativeMethods.GetPrinterW(this._deviceHandle, dwLevel, pPrinterBuffer.Handle, dwNeeded, ref dwNeeded))
{
action(pPrinterBuffer);
return(true);
}
}
finally
{
pPrinterBuffer.Release();
}
}
return(false);
}
/// <summary>
/// A callback that copies PRINTER_INFO_2 fields from an unmanaged buffer
/// </summary>
public void Callback(HGlobalBuffer pPrinterBuffer)
{
// PRINTER_INFO_2 layout from http://msdn.microsoft.com/en-us/library/dd162845(VS.85).aspx
//
//typedef struct _PRINTER_INFO_2 {
// LPTSTR pServerName;
// LPTSTR pPrinterName;
// LPTSTR pShareName;
// LPTSTR pPortName;
// LPTSTR pDriverName;
// LPTSTR pComment;
// LPTSTR pLocation;
// LPDEVMODE pDevMode;
// LPTSTR pSepFile;
// LPTSTR pPrintProcessor;
// LPTSTR pDatatype;
// LPTSTR pParameters;
// PSECURITY_DESCRIPTOR pSecurityDescriptor;
// DWORD Attributes;
// DWORD Priority;
// DWORD DefaultPriority;
// DWORD StartTime;
// DWORD UntilTime;
// DWORD Status;
// DWORD cJobs;
// DWORD AveragePPM;
// } PRINTER_INFO_2, *PPRINTER_INFO_2;
PRINTER_INFO_2 = new PRINTER_INFO_2();
bool shouldRelease = false;
pPrinterBuffer.Handle.DangerousAddRef(ref shouldRelease);
try
{
IntPtr ptr = pPrinterBuffer.Handle.DangerousGetHandle();
// LPTSTR pPrinterName;
IntPtr pPrinterName = Marshal.ReadIntPtr(ptr, 1 * Marshal.SizeOf(typeof(IntPtr)));
if (pPrinterName != IntPtr.Zero)
{
PRINTER_INFO_2.pPrinterName = Marshal.PtrToStringUni(pPrinterName);
}
// LPTSTR pPortName;
IntPtr pPortName = Marshal.ReadIntPtr(ptr, 3 * Marshal.SizeOf(typeof(IntPtr)));
if (pPortName != IntPtr.Zero)
{
PRINTER_INFO_2.pPortName = Marshal.PtrToStringUni(pPortName);
}
// LPTSTR pDriverName;
IntPtr pDriverName = Marshal.ReadIntPtr(ptr, 4 * Marshal.SizeOf(typeof(IntPtr)));
if (pDriverName != IntPtr.Zero)
{
PRINTER_INFO_2.pDriverName = Marshal.PtrToStringUni(pDriverName);
}
// LPDEVMODE pDevMode;
IntPtr pDevMode = Marshal.ReadIntPtr(ptr, 7 * Marshal.SizeOf(typeof(IntPtr)));
if (pDevMode != IntPtr.Zero)
{
PRINTER_INFO_2.pDevMode = DevMode.FromIntPtr(pDevMode);
}
}
finally
{
if (shouldRelease)
{
pPrinterBuffer.Handle.DangerousRelease();
}
}
}