CreateDC在203rd循环上抛出错误。 [英] CreateDC throws error on 203rd loop.

问题描述

大家好，


我正在写一些互操作代码将图形打印到eps文件

我使用adobe打印机驱动程序。我写的代码是

正常工作。但如果我循环超过200次，则会产生

错误。任何人都可以告诉我它为什么会抛出错误或者我有记忆

问题？我通过它进行了调试，我发现createDC在203rd循环中返回0

并抛出异常。为什么createDC返回0？

这是执行互操作的代码段。


使用System;

using System.Drawing;

使用System.IO;

使用System.Drawing.Printing;

使用System.Runtime.InteropServices;

使用System.Drawing.Text;


命名空间打印机

{

公共类CPrinter

{

私人图形pDC;

私人IntPtr dc1;

私人IntPtr hdevmode;


[StructLayout（LayoutKind.Sequential）]

public struct DOCINFO

{

[MarshalAs（UnmanagedType.LPWStr）] public string pDocName ;

[MarshalAs（UnmanagedType.LPWStr）] public string pOutputFile;

[MarshalAs（UnmanagedType.LPWStr）] public string pDataType;

}


[DllImport（

" winspool.drv"，CharSet = CharSet.Unicode，ExactSpelli ng = false，

CallingConvention = CallingConvention.StdCall ）]

public static extern long StartDocPrinter（IntPtr hPrinter，int Level，

ref DOCINFO pDocInfo）;


[DllImport（ " gdi32.dll"，EntryPoint =" CreateDCA"）]

public static extern IntPtr CreateDC（string lpDriverName，string

lpDeviceName，

string lpOutput，IntPtr pDevMode）;


[DllImport（" gdi32.dll"）]

static extern bool DeleteDC（IntPtr hdc）;


[DllImport（" gdi32"，EntryPoint =" StartDocA"）]

public static extern int StartDoc（IntPtr dc1，ref DOCINFO di）;


[DllImport（" gdi32"）] public static extern int StartPage（IntPtr hDC）;

[DllImport（" gdi32"）] public static extern int EndDoc（IntPtr hDC）;


[DllImport（" gdi32"）] public static extern int EndPage（IntPtr hDC）;


public CPrinter（）

{

}

public void StartPrinter（string ou tputFile）

{

试试

{

DOCINFO di =新DOCINFO（）;

di.pOutputFile = outputFile;

PrintDocument pd = new PrintDocument（）;

hdevmode = pd.PrinterSettings.GetHdevmode（）;

dc1 = CreateDC（""，" Acrobat Distiller 3x2"，outputFile，hdevmode）;

int result = StartDoc（dc1，ref di）;

结果= StartPage（dc1）;

pDC = Graphics.FromHdc（dc1）;

pDC.PageUnit = GraphicsUnit.Pixel;

}

catch（Exception ex）

{

throw（ex）;

}

}


public void EndPrinter（）

{

int result = EndPage（dc1）;

result = EndDoc（dc1）;

DeleteDC（dc1）;

}

}

}


这是我循环的代码段：


使用系统;

使用打印机;


命名空间ConsoleApplication1

{

class Class1

{

[STAThread]

static void Main（string [] args）

{

int i = 0;

尝试

{

而（true）

{

CPrinter Adob​​ePrinter = new CPrinter（）;

Adob​​ePrinter.StartPrinter（" temp.wrk"）;

Adob​​ePrinter.EndPrinter（）;

i ++;

Console.WriteLine（i）;

}

}

catch（例外情况ex）

{

Console.WriteLine（i +" ： + ex）;

}

}

}

}


谢谢，

Lalasa。

Hi guys,

I am writing some interop code to print graphics to an eps file
and I use adobe printer driver. The piece of code I have written is
working fine. but if I loop for more than 200 times, it is throwing an
error. Can anybody tell me why it throws an error or am I having memory
problems? I debuged through it and I see that createDC is returning 0
on 203rd loop and throws an exception. Why is createDC returning a 0?
This is the piece of code that does the interop.

using System;
using System.Drawing;
using System.IO;
using System.Drawing.Printing;
using System.Runtime.InteropServices;
using System.Drawing.Text;

namespace Printer
{
public class CPrinter
{
private Graphics pDC;
private IntPtr dc1;
private IntPtr hdevmode;

[StructLayout( LayoutKind.Sequential)]
public struct DOCINFO
{
[MarshalAs(UnmanagedType.LPWStr)]public string pDocName;
[MarshalAs(UnmanagedType.LPWStr)]public string pOutputFile;
[MarshalAs(UnmanagedType.LPWStr)]public string pDataType;
}

[DllImport(
"winspool.drv",CharSet=CharSet.Unicode,ExactSpelli ng=false,
CallingConvention=CallingConvention.StdCall )]
public static extern long StartDocPrinter(IntPtr hPrinter, int Level,
ref DOCINFO pDocInfo);

[DllImport("gdi32.dll", EntryPoint="CreateDCA")]
public static extern IntPtr CreateDC(string lpDriverName, string
lpDeviceName,
string lpOutput, IntPtr pDevMode);

[DllImport("gdi32.dll")]
static extern bool DeleteDC(IntPtr hdc);

[DllImport("gdi32", EntryPoint="StartDocA")]
public static extern int StartDoc(IntPtr dc1, ref DOCINFO di);

[DllImport("gdi32")] public static extern int StartPage(IntPtr hDC);
[DllImport("gdi32")] public static extern int EndDoc(IntPtr hDC);

[DllImport("gdi32")] public static extern int EndPage(IntPtr hDC);

public CPrinter()
{
}
public void StartPrinter(string outputFile)
{
try
{
DOCINFO di = new DOCINFO();
di.pOutputFile = outputFile;
PrintDocument pd = new PrintDocument();
hdevmode = pd.PrinterSettings.GetHdevmode();
dc1 = CreateDC("","Acrobat Distiller 3x2",outputFile,hdevmode);
int result = StartDoc(dc1, ref di);
result = StartPage(dc1);
pDC = Graphics.FromHdc(dc1);
pDC.PageUnit = GraphicsUnit.Pixel;
}
catch(Exception ex)
{
throw(ex);
}
}

public void EndPrinter()
{
int result = EndPage(dc1);
result = EndDoc(dc1);
DeleteDC(dc1);
}
}
}

This is the piece of code where I loop :

using System;
using Printer;

namespace ConsoleApplication1
{
class Class1
{
[STAThread]
static void Main(string[] args)
{
int i = 0;
try
{
while (true)
{
CPrinter AdobePrinter = new CPrinter();
AdobePrinter.StartPrinter("temp.wrk");
AdobePrinter.EndPrinter();
i++;
Console.WriteLine(i);
}
}
catch (Exception ex)
{
Console.WriteLine( i + " : " + ex);
}
}
}
}

Thanks,
Lalasa.

推荐答案

" L" < LA ******** @ investors.com>在消息中写道

news：11 ********************** @ o13g2000cwo.googlegr oups.com ...

"L" <la********@investors.com> wrote in message
news:11**********************@o13g2000cwo.googlegr oups.com...

大家好，

我正在写一些互操作代码将图形打印到eps文件
我使用adobe打印机驱动程序。我写的代码片段工作正常。但如果我循环超过200次，则会出现
错误。任何人都能告诉我它为什么会抛出错误或者我有记忆问题吗？我通过它进行了调试，我发现createDC在203rd循环中返回0
并抛出异常。为什么createDC返回0？

您正在使用Disposable对象（Graphics）而不进行处理。


这是一段代码互操作。

使用System;
使用System.Drawing;
使用System.IO;
使用System.Drawing.Printing;
使用System.Runtime.InteropServices;
使用System.Drawing.Text;

名称空间打印机
公共类CPrinter
{
私有图形pDC;
私人IntPtr dc1;
私人IntPtr hdevmode;

[StructLayout（LayoutKind.Sequential）]
公共结构DOCINFO
{
[MarshalAs（UnmanagedType.LPWStr）] public string pDocName;
[MarshalAs（UnmanagedType.LPWStr）] public string pOutputFile;
[MarshalAs（UnmanagedType.LPWStr）] public string pDataType;
}

[DllImport（
" winspool.drv"，CharSet = CharSet.Unicode，ExactSpelli ng = false，
CallingConvention = CallingConvention.StdCall）]
公共静态extern long StartDocPrinter（IntPtr hPrinter，int Level，
ref DOCINFO pDocInfo）;

[DllImport（" gdi32.dll"，EntryPoint =" CreateDCA"）]
public static extern IntPtr CreateDC（string lpDriverName，string
lpDeviceName，
string lpOutput，IntPtr pDevMode）;

[DllImport（" gdi32.dll"）]
static extern bool DeleteDC（IntPtr hdc）;

[DllImport（" gdi32"，EntryPoint =" StartDocA"）]
public static extern int StartDoc（IntPtr dc1，ref DOCINFO di）;

[DllImport（" gdi32"）] public static extern int StartPage（IntPtr hDC）;

[DllImport（" gdi32"）] public static extern int EndDoc（ IntPtr hDC）;

[DllImport（" gdi32"）] public static extern int EndPage（IntPtr hDC）;

公共CPrinter（）
{
}
public void StartPrinter（string outputFile）
{
尝试
{DOCINFO di = new DOCINFO（）;
di.pOutputFile = outputFile ;
PrintDocument pd = new PrintDocument（）;
hdevmode = pd.PrinterSettings.GetHdevmode（）;
dc1 = CreateDC（""，" Acrobat Distiller 3x2"，outputFile，hdevmode）;
int result = StartDoc（dc1，ref di）;
result = StartPage（dc1）;
pDC = Graphics.FromHdc（dc1）;
pDC.PageUnit = GraphicsUnit.Pixel;
}
catch（Exception ex）
{
throw（ex）;
}


public void EndPrinter（ ）
{
int result = EndPage（dc1）;
result = EndDoc（dc1）;
DeleteDC（dc1）;
}
}
使用System;
使用Printer;

命名空间ConsoleApplication1
{class class
{STAThread]
static void Main（string [] args）
{
int i = 0; <尝试
{
while（true）
{
CPrinter Adob​​ePrinter = new CPrinter（）;
Adob​​ePrinter.StartPrinter（" temp.wrk"）;
Adob​​ePrinter.EndPrinte r（）;
i ++;
Console.WriteLine（i）;
}
}
catch（Exception ex）
{
控制台.WriteLine（i +" ： + ex）;
}
}
}

谢谢，Lalasa。

Hi guys,

I am writing some interop code to print graphics to an eps file
and I use adobe printer driver. The piece of code I have written is
working fine. but if I loop for more than 200 times, it is throwing an
error. Can anybody tell me why it throws an error or am I having memory
problems? I debuged through it and I see that createDC is returning 0
on 203rd loop and throws an exception. Why is createDC returning a 0?

You are using a Disposable object (Graphics) without disposing it.


This is the piece of code that does the interop.

using System;
using System.Drawing;
using System.IO;
using System.Drawing.Printing;
using System.Runtime.InteropServices;
using System.Drawing.Text;

namespace Printer
{
public class CPrinter
{
private Graphics pDC;
private IntPtr dc1;
private IntPtr hdevmode;

[StructLayout( LayoutKind.Sequential)]
public struct DOCINFO
{
[MarshalAs(UnmanagedType.LPWStr)]public string pDocName;
[MarshalAs(UnmanagedType.LPWStr)]public string pOutputFile;
[MarshalAs(UnmanagedType.LPWStr)]public string pDataType;
}

[DllImport(
"winspool.drv",CharSet=CharSet.Unicode,ExactSpelli ng=false,
CallingConvention=CallingConvention.StdCall )]
public static extern long StartDocPrinter(IntPtr hPrinter, int Level,
ref DOCINFO pDocInfo);

[DllImport("gdi32.dll", EntryPoint="CreateDCA")]
public static extern IntPtr CreateDC(string lpDriverName, string
lpDeviceName,
string lpOutput, IntPtr pDevMode);

[DllImport("gdi32.dll")]
static extern bool DeleteDC(IntPtr hdc);

[DllImport("gdi32", EntryPoint="StartDocA")]
public static extern int StartDoc(IntPtr dc1, ref DOCINFO di);

[DllImport("gdi32")] public static extern int StartPage(IntPtr hDC);
[DllImport("gdi32")] public static extern int EndDoc(IntPtr hDC);

[DllImport("gdi32")] public static extern int EndPage(IntPtr hDC);

public CPrinter()
{
}
public void StartPrinter(string outputFile)
{
try
{
DOCINFO di = new DOCINFO();
di.pOutputFile = outputFile;
PrintDocument pd = new PrintDocument();
hdevmode = pd.PrinterSettings.GetHdevmode();
dc1 = CreateDC("","Acrobat Distiller 3x2",outputFile,hdevmode);
int result = StartDoc(dc1, ref di);
result = StartPage(dc1);
pDC = Graphics.FromHdc(dc1);
pDC.PageUnit = GraphicsUnit.Pixel;
}
catch(Exception ex)
{
throw(ex);
}
}

public void EndPrinter()
{
int result = EndPage(dc1);
result = EndDoc(dc1);
DeleteDC(dc1);
}
}
}

This is the piece of code where I loop :

using System;
using Printer;

namespace ConsoleApplication1
{
class Class1
{
[STAThread]
static void Main(string[] args)
{
int i = 0;
try
{
while (true)
{
CPrinter AdobePrinter = new CPrinter();
AdobePrinter.StartPrinter("temp.wrk");
AdobePrinter.EndPrinter();
i++;
Console.WriteLine(i);
}
}
catch (Exception ex)
{
Console.WriteLine( i + " : " + ex);
}
}
}
}

Thanks,
Lalasa.

我将pDC.Dispose（）添加到我的EndPrinter（）函数中，但仍然是我有问题的b $ b。


public void EndPrinter（）

{

int result = EndPage（dc1）;

result = EndDoc （dc1）;

pDC.Dispose（）;

DeleteDC（dc1）;

}


谢谢，

L.

I added the pDC.Dispose() to my EndPrinter() function and still I am
having the problem.

public void EndPrinter()
{
int result = EndPage(dc1);
result = EndDoc(dc1);
pDC.Dispose();
DeleteDC(dc1);
}

Thanks,
L.

有人可以告诉我它为什么会抛出错误还是我有记忆问题？


你正在释放GetHDevmode返回的句柄。


public static extern long StartDocPrinter（IntPtr hPrinter，int Level，

Can anybody tell me why it throws an error or am I having memory
problems?
You''re net freeing the handle returned by GetHDevmode.

public static extern long StartDocPrinter(IntPtr hPrinter, int Level,

^^^^


返回类型应为（u）int。


Mattias


-

Mattias Sj？gren [MVP] mattias @ mvps.org
http://www.msjogren.net/dotnet/ | http://www.dotnetinterop.com

请只回复新闻组。

^^^^

The return type should be (u)int.

Mattias

--
Mattias Sj?gren [MVP] mattias @ mvps.org
http://www.msjogren.net/dotnet/ | http://www.dotnetinterop.com
Please reply only to the newsgroup.

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