EnumDisplayDevices - second attempt

[AlexS]

Hi, I posted this in m.p.d.f.interop but did not get any sensible response.
Maybe somebody will be able to point me to right direction here?

Hi,

I am having some issue with EnumDisplayDevices when called from C#.
When I use CharSet.Ansi (note - no unicode) for DISPLAY_DEVICE structure, I
get

0, DISPLAY1, raphics SuperSavage/IXC 1014, 1548305232,
VEN_5333&DEV_8C2E&SUBSYS_01FC1014&REV_05,
ISTRY\Machine\System\ControlSet001\Services\S3SSavage\Device0

1, DISPLAY3, eeting driver, 0, ,
ISTRY\Machine\System\ControlSet001\Services\mnmdd\Device0



When I try to use unicode (CharSet.Auto) I get garbage in device name, key,
string etc.

Platform SDK help says that display_device structure strings must be
declared as WCHAR, which means unicode. Or not?

And why some strings are losing starting symbols?



Here is declaration I use

[StructLayout(LayoutKind.Sequential, CharSet=CharSet.Ansi)]

public class DISPLAY {

public long cb=0;

[MarshalAs(UnmanagedType.ByValTStr,SizeConst=32)]

public string DeviceName=new String(' ',32);

[MarshalAs( UnmanagedType.ByValTStr, SizeConst=128)]

public string DeviceString=new String(' ',128);

public int StateFlags=0;

[MarshalAs( UnmanagedType.ByValTStr, SizeConst=128)]

public string DeviceID=new String(' ',128);

[MarshalAs( UnmanagedType.ByValTStr, SizeConst=128)]

public string DeviceKey=new String(' ',128);

}

[DllImport("user32.dll")]

extern static bool EnumDisplayDevices(IntPtr lpDevice,

int iDevNum,

[In,Out] DISPLAY lpDisplayDevice,

int dwFlags);

and here is how function is called:



DISPLAY d=new DISPLAY();

d.cb=Marshal.SizeOf(d);

int id=0;

int dwf=0;

while (EnumDisplayDevices(IntPtr.Zero, id, d, dwf)) {

Console.WriteLine(

String.Format("{0}, {1}, {2}, {3}, {4}, {5}",

id,

d.DeviceName,

d.DeviceString,

d.StateFlags,

d.DeviceID,

d.DeviceKey

)

);

id++;

d.cb=Marshal.SizeOf(d);

}



What is wrong here?

Anybody can help?



Thanks

Alex

 

[Francois Beaussier]

:

Hi, I posted this in m.p.d.f.interop but did not get any sensible response.
Maybe somebody will be able to point me to right direction here?

Lets try

I am having some issue with EnumDisplayDevices when called from C#.
When I use CharSet.Ansi (note - no unicode) for DISPLAY_DEVICE structure, I
get

0, DISPLAY1, raphics SuperSavage/IXC 1014, 1548305232,
VEN_5333&DEV_8C2E&SUBSYS_01FC1014&REV_05,
ISTRY\Machine\System\ControlSet001\Services\S3SSavage\Device0

1, DISPLAY3, eeting driver, 0, ,
ISTRY\Machine\System\ControlSet001\Services\mnmdd\Device0

Here is declaration I use

[StructLayout(LayoutKind.Sequential, CharSet=CharSet.Ansi)]

public class DISPLAY {

public long cb=0;

Just write "int" instead of "long" here. That will do

 

[AlexS]

Thanks, Francois

Somehow I assumed that long is same as int in this case. My bad.

Alex

:

Hi, I posted this in m.p.d.f.interop but did not get any sensible response.
Maybe somebody will be able to point me to right direction here?

Lets try

I am having some issue with EnumDisplayDevices when called from C#.
When I use CharSet.Ansi (note - no unicode) for DISPLAY_DEVICE

structure,

I
get

0, DISPLAY1, raphics SuperSavage/IXC 1014, 1548305232,
VEN_5333&DEV_8C2E&SUBSYS_01FC1014&REV_05,
ISTRY\Machine\System\ControlSet001\Services\S3SSavage\Device0

1, DISPLAY3, eeting driver, 0, ,
ISTRY\Machine\System\ControlSet001\Services\mnmdd\Device0

Here is declaration I use

[StructLayout(LayoutKind.Sequential, CharSet=CharSet.Ansi)]

public class DISPLAY {

public long cb=0;

Just write "int" instead of "long" here. That will do