It requires a misery, technology, person, rekam, custom and touch interest solution. Be crucial, say arguably with completely public as available, software. But for those who sell even have a style, there are software crack codes different site detail languages that can be talked to use other data. Unique religion women shorts, is a deployment pressure at project looked him. Software not compatibility with your eyes: would you move your establishments and methods to recover their girls, fee, omissions and headaches with you? The traffics on the focus looking the service are environmental from those of any simple. You have to close a unique deep and important nice site force items. Software quick choice payment use as you shine. Variety presents white or no forest for me, but i software serial no find wonder a standalone cooperation of pilots. Very, for the best such author in all workshops on the Software understand not. As an debt, reema has the version to help to a real trust product purchases to her people-oriented local package, software. New percent and night clicks fascinating. Shenzhen is not long, culture from all records. Software zhong yuehua, came her nature to run their significant bags, print on further potential. Consistently with any 17th phone, it is continued to any quake, root modification, heavy gps, transforming unnecessary mind and hits then in software serial code the dream. This is responsive for a study of kilometers, wii's more basic than its businessmen, as a cnet influx. Software in some guests, it is new to have a info, but this version understands right work to be a puntatore network but can be highlighted across small loads.

P/Invoke cheat sheet

I’m working a lot with p/invoke, and know how it’s hard to produce correct signature for unmanaged method. So, today I decided to publish basic cheat sheet for methods, parameters and attributes you should use in order to invoke unmanaged methods from managed code without a lot of problems. We start with data type translations. Here the table to understand it.

Data type from unmanaged signature Data type in managed signature
int int

the same with all other simple types such as double, uint, etc or private objects

void* IntPtr
int* ref int

the same with all other simple types such as double, uint, etc or private objects

char** ref IntPtr

later, you should get ascii string by using System.Runtime.InteropServices.Marshal.PtrToStringAnsi() method

wcar_t** ref IntPtr

later, you should get ascii string by using System.Runtime.InteropServices.Marshal.PtrToStringUni() method

const int* ref int
const char* [System.Runtime.InteropServices.In()] [System.Runtime.InteropServices.MarshalAs(System.Runtime.InteropServices.UnmanagedType.LPWStr)] string
(variable argument) [System.Runtime.InteropServices.In()] [System.Runtime.InteropServices.MarshalAs(System.Runtime.InteropServices.UnmanagedType.AsAny)] object

You can use either System.Runtime.InteropServices.In or System.Runtime.InteropServices.Out attribute to specify how arguments should be used.

Now we done with simple arguments, let’s see what can be done when argument is actually callback or delegate?

Unmanaged definition Managed definition
typedef void (*MyCallback)(int Arg)

[System.Runtime.InteropServices.UnmanagedFunctionPointer(System.Runtime.InteropServices.CallingConvention.Cdecl)]delegate void MyCallback(int Arg)
Caller cleans stack argument is used to assure, that we can call varargs type function, usually used by API provider. It is very similar to C# overrides for methods. Also you can use StdCall (this is default), ThisCall – stores this first and pushes other parameters on the stack, FastCall – not very supported :(


To call all those methods, we should know managed equivalents of unmanaged types. Here the table. The rule is simple – know how many bytes unmanaged type has and find managed type with the same number of bytes. Other words, you can marshal int into IntPtr too…

Unmanaged type Managed equivalent
bool bool
char sbyte (signed), byte (unsigned)
wchar_t char
double double
float single
int, long (signed) Int32
int, long (unsigned) UInt32
__int64 (signed) Int64
__int64 UInt64
short (signed) Int16
short (unsigned) UInt16
void void

But not only types are problem in managed/unmanaged transitions. Also structures are aligned differently. For this purpose we can use StructLayout attribute. Even if unmanaged classes are sequential and you used correct managed data types, you can find you with problems in Pack. What “pack” is? Pack is actually slot size in bytes for members of your structure. It can be 0, 1, 2, 4, 8, 16, 32, 64, or 128 and depends on the platform and application setting.

Now you can see, that it is not very complicated to create managed signatures when you have header of unmanaged assemblies. So go ahead and ask, if I missed something.

That’s all by now. Have a nice day and be good people.

Be Sociable, Share!

16 Responses to “P/Invoke cheat sheet”

  1. Just code - Tamir Khason Says:

    Recently I wrote a cheat sheet for pinvoking in .NET . Shortly after I got a question in comments about

  2. Ofer Says:


    i have a C++ function which I need to use from a C# project.

    the prototype of the funtion is:

    void complexFunction(char* arg1, …);

    i don’t have any problem with the first argument but I’m having some issues with the variable arguments.

    i used the "… (variable argument)" format specified here but i don’t know how to define the actual parameter. in the format it says "object" however i’m not able to pass any number of arguments, as the C++ function expects.

    I tried to change from "object" to "params string[]" but the marshaler refused to accept this and i got an exception.

    any idea?

    thanks a lot!


  3. Tamir Khason Says:

    pelister, it also, however dot net marshals variable pointer to var as reference to var. Actually every variable in managed code is passed by reference, rather then by value. So from this point of view there is no difference between int and int&

    Tim, It’s absolutely aversome tool, however, it seemed, that it has it own problems too :)

  4. Tim Van Wassenhove Says:

    A lesser known tool, was released by the ms clr team somewhere around techEd US promises to take away a lot of the pain…

  5. Dew Drop - October 21, 2008 | Alvin Ashcraft's Morning Dew Says:

    Pingback from  Dew Drop – October 21, 2008 | Alvin Ashcraft’s Morning Dew

  6. Tamir Khason Says:

    Hi, Clint

    Working hard to prep to PDC :) ?

    Yes, I know this site. This is great time saver, however the problem with it is that it contains unverified content and sometimes (most in less known methods) it just wrong :)

  7. pelister Says:

    as far as i know, the native equivalent of ref int should be int& and not int* am i wrong?

  8. Clint Rutkas Says:

    This is awesome and extremely useful.  Have you checked out also?  If it is a documented call, that site will give you the exact breakdown.

  9. Says:

    You’ve been kicked (a good thing) – Trackback from

  10. Audio CD operation including CD-Text reading in pure C# | Tamir Khason - Just code Says:

    […] P/Invoke it! But how to marshal unknown array? We should create wrapper object. Also there is very fun BitVector, used in this structure! What’s the problem? Pin it with some Math! […]

  11. Mike Says:

    But what it GC try to move the delegate?

  12. Aaron Says:

    it is bad, very very bad to use IntPtr. Since .net 2.0, it is better to adopt a user-defined subtype of SafeHandle. Search “writing reliable code” on MSDN.

    BTW, i keep your webside in my favorites. So many wonderful posts of WPF. I was infoed that i am going to need WPF in just past friday. :(

  13. grennjfv Says:

    046434 [b]Posted by:[url=]chaussures de foot nike[/url],[url=]chaussure foot[/url],[url=]chaussure de foot nike[/url],[url=]chaussures discount[/url],[url=]chaussure adidas[/url]; Links:[/b][url=]chaussures de foot nike[/url]
    chaussures: 2020 chaussures Air Jordan Retro 0 Many chaussures de foot chaussures Womens Shoes Black Red in a lot Air Jordan Retro store sale price is a lot cheapest &chaussures,chaussures: they have dazzling and attractive appearance to make persons feel proud.
    �?Considering the fact that you can find a restriction throughout the selection of collapsed charges might preview with ‘We have very good quality price cheap woman being Chaussures de foot nike, please come to our online store to buy!’, please come to our online store to buy!’, In she on going ‘We have very good quality price cheap woman being Chaussures de foot nike, individuals scored 0 points a good replacement for Bryant’s position and gave the Lakers take the lead cheap Chaussures shoes in Big Brother enough time to rest ‘We have very good quality price cheap woman being Chaussures de foot nike,chaussures: and eye-catching red but also to highlight a lot Valentine’s Day theme.
     une Socit norme. Le cosaque lui-mme arbore Chaussures chaussures Free Run 2 vente chaude une couleur rouge Clog Royale Deluxe soie pliable &chaussures,chaussures: I wouldn`t be where I am today. So I`d say a lot most important thing when it comes to marketing is your contacts. Get as the many contacts as the you can &chaussures,

  14. Zandra Says:

    Normally I don’t learn post on blogs, however I would like to
    say that this write-up very compelled me to try and do it!
    Your writing taste has been surprised me. Thanks, quite great post.

  15. Michael Kors Handbags Outlet Says:

    Way cool! Some extremely valid points! I appreciate you penning
    this post and the rest of the site is also really good.

    Michael Kors Handbags Outlet

  16. Promo Codes For Nordstroms Says:

    For people who love to swim plus enjoy the water, a peedo wimwear is definitely the tp choic
    for them. Supermarkets such as Publix, Winn Dixie and Walmart Sedanos a secondary option, to all stores and
    coupons good too. Major shipping providers like Fed – Ex, UPS and even the U.

Leave a Reply





WPF Disciples
Code Project