转自：http://www.jb51.net/article/42514.htm
c#在调用c++方法或者window api时不能象调用c#本身写的dll类库那样直接通过引用dll就可以调用相应的方法, 而是要把要引用的dll放到bin中,现通过[DllImport("um_web_client.dll")]引用
例子1如下:

1. 
   
2. //声明部分
   
3. [DllImport("um_web_client.dll")]
   
4. private static extern int CheckUserName(string UserName);
   
5. //
   
6. public static int AuthUserName(string username)
   
7. {
   
8. if(!IsConnection())
   
9. {
   
10. StartWebClient(UDBClientIP,UDBClientPort,UDBClientTimeout);
    
11. }
    
12. return CheckUserName(username);
    
13. }

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但是如果c++方法中用了指针或者结构体等则引用就要注意,相应就要用到引用数组或者指针,例子2:
声明部分
但是如果c++方法中用了指针或者结构体等则引用就要注意,相应就要用到引用数组或者指针,例子2:

声明部分

1. 
   
2. [StructLayout(LayoutKind.Sequential, CharSet=CharSet.Ansi )]
   
3. public class tagPlayerInfoOut
   
4. {
   
5. public int id;
   
6. public String PlayerName;
   
7. public int Country;
   
8. public int OfficerRace;
   
9. public int Level;
   
10. public int MilitaryRank;
    
11. public int Money;
    
12. public int ResourceCount;
    
13. public int CityCount;
    
14. public int GeneralCount;
    
15. public int Credit;
    
16. }
    
17. [ StructLayout( LayoutKind.Sequential )]
    
18. public struct tagPlayerInfoOutEx
    
19. {
    
20. public int id;
    
21. public IntPtr PlayerName;
    
22. public int Country;
    
23. public int OfficerRace;
    
24. public int Level;
    
25. public int MilitaryRank;
    
26. public int Money;
    
27. public int ResourceCount;
    
28. public int CityCount;
    
29. public int GeneralCount;
    
30. public int Credit;
    
31. }
    
32. 
    
33. [DllImport("um_web_client.dll")]
    
34. public static extern int GetPlayerListCs(int maxrows, out int rows, out IntPtr playerlist);
    
35. [DllImport("um_web_client.dll")]
    
36. public static extern int GetPlayerListCs(int maxrows, out int rows, tagPlayerInfoOutEx** playerlist);

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方法

1. 
   
2. public static DataTable UsingMarshal()
   
3. {
   
4. if(!IsConnection())
   
5. {
   
6. StartWebClient(UDBClientIP,UDBClientPort,UDBClientTimeout);
   
7. }
   
8. DataTable dt = new DataTable();
   
9. dt.Columns.Add("id");
   
10. dt.Columns.Add("PlayerName");
    
11. dt.Columns.Add("Country");
    
12. dt.Columns.Add("OfficerRace");
    
13. dt.Columns.Add("Level");
    
14. dt.Columns.Add("MilitaryRank");
    
15. dt.Columns.Add("Money");
    
16. dt.Columns.Add("ResourceCount");
    
17. dt.Columns.Add("CityCount");
    
18. dt.Columns.Add("GeneralCount");
    
19. dt.Columns.Add("Credit");
    
20. int size = 0;
    
21. IntPtr outArray;
    
22. GetPlayerListCs(20, out size, out outArray);
    
23. tagPlayerInfoOut[] manArray = new tagPlayerInfoOut[size];
    
24. IntPtr current = outArray;
    
25. //Console.WriteLine("记录数{0}",size);
    
26. 
    
27. for( int i = 0; i < size; i++ )
    
28. {
    
29. manArray[ i ] = new tagPlayerInfoOut();
    
30. Marshal.PtrToStructure(current, manArray[i]);
    
31. Marshal.DestroyStructure(current, typeof(tagPlayerInfoOut) );
    
32. current = (IntPtr)((long)current + Marshal.SizeOf(manArray[i]));
    
33. dt.Rows.Add(new object[] {manArray[i].id,manArray[i].PlayerName,manArray[i].Country,manArray[i].OfficerRace,manArray[i].Level,manArray[i].MilitaryRank,manArray[i].Money,manArray[i].ResourceCount,manArray[i].CityCount,manArray[i].GeneralCount,manArray[i].Credit});
    
34. dt.AcceptChanges();
    
35. //Console.WriteLine( "Element {0}: {1} {2}", i, manArray[i].id, manArray[i].PlayerName);
    
36. }
    
37. Marshal.FreeCoTaskMem(outArray);
    
38. return dt;
    
39. }
    
40. public static unsafe DataTable UsingUnsafe()
    
41. {
    
42. int size;
    
43. if(!IsConnection())
    
44. {
    
45. StartWebClient(UDBClientIP,UDBClientPort,UDBClientTimeout);
    
46. }
    
47. DataTable dt = new DataTable();
    
48. dt.Columns.Add("id");
    
49. dt.Columns.Add("PlayerName");
    
50. dt.Columns.Add("Country");
    
51. dt.Columns.Add("OfficerRace");
    
52. dt.Columns.Add("Level");
    
53. dt.Columns.Add("MilitaryRank");
    
54. dt.Columns.Add("Money");
    
55. dt.Columns.Add("ResourceCount");
    
56. dt.Columns.Add("CityCount");
    
57. dt.Columns.Add("GeneralCount");
    
58. dt.Columns.Add("Credit");
    
59. tagPlayerInfoOutEx* pResult;
    
60. GetPlayerListCs(20, out size, &pResult );
    
61. tagPlayerInfoOutEx* pCurrent = pResult;
    
62. //Console.WriteLine("记录数{0}",size);
    
63. for( int i = 0; i < size; i++, pCurrent++ )
    
64. {
    
65. //Console.WriteLine( "Element {0}: {1} {2}", i, pCurrent->id ,Marshal.PtrToStringAnsi(pCurrent->PlayerName));
    
66. //Marshal.FreeCoTaskMem(pCurrent->PlayerName );
    
67. dt.Rows.Add(new object[] {pCurrent->id,pCurrent->PlayerName,pCurrent->Country,pCurrent->OfficerRace,pCurrent->Level,pCurrent->MilitaryRank,pCurrent->Money,pCurrent->ResourceCount,pCurrent->CityCount,pCurrent->GeneralCount,pCurrent->Credit});
    
68. dt.AcceptChanges();
    
69. }
    
70. Marshal.FreeCoTaskMem((IntPtr)pResult );
    
71. return dt;
    
72. }

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转自：http://www.jb51.net/article/42514.htm
c#在调用c++方法或者window api时不能象调用c#本身写的dll类库那样直接通过引用dll就可以调用相应的方法, 而是要把要引用的dll放到bin中,现通过[DllImport("um_web_client.dll")]引用
例子1如下:

1. 
   
2. //声明部分
   
3. [DllImport("um_web_client.dll")]
   
4. private static extern int CheckUserName(string UserName);
   
5. //
   
6. public static int AuthUserName(string username)
   
7. {
   
8. if(!IsConnection())
   
9. {
   
10. StartWebClient(UDBClientIP,UDBClientPort,UDBClientTimeout);
    
11. }
    
12. return CheckUserName(username);
    
13. }

复制代码

但是如果c++方法中用了指针或者结构体等则引用就要注意,相应就要用到引用数组或者指针,例子2:
声明部分
但是如果c++方法中用了指针或者结构体等则引用就要注意,相应就要用到引用数组或者指针,例子2:

声明部分

1. 
   
2. [StructLayout(LayoutKind.Sequential, CharSet=CharSet.Ansi )]
   
3. public class tagPlayerInfoOut
   
4. {
   
5. public int id;
   
6. public String PlayerName;
   
7. public int Country;
   
8. public int OfficerRace;
   
9. public int Level;
   
10. public int MilitaryRank;
    
11. public int Money;
    
12. public int ResourceCount;
    
13. public int CityCount;
    
14. public int GeneralCount;
    
15. public int Credit;
    
16. }
    
17. [ StructLayout( LayoutKind.Sequential )]
    
18. public struct tagPlayerInfoOutEx
    
19. {
    
20. public int id;
    
21. public IntPtr PlayerName;
    
22. public int Country;
    
23. public int OfficerRace;
    
24. public int Level;
    
25. public int MilitaryRank;
    
26. public int Money;
    
27. public int ResourceCount;
    
28. public int CityCount;
    
29. public int GeneralCount;
    
30. public int Credit;
    
31. }
    
32. 
    
33. [DllImport("um_web_client.dll")]
    
34. public static extern int GetPlayerListCs(int maxrows, out int rows, out IntPtr playerlist);
    
35. [DllImport("um_web_client.dll")]
    
36. public static extern int GetPlayerListCs(int maxrows, out int rows, tagPlayerInfoOutEx** playerlist);

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方法

1. 
   
2. public static DataTable UsingMarshal()
   
3. {
   
4. if(!IsConnection())
   
5. {
   
6. StartWebClient(UDBClientIP,UDBClientPort,UDBClientTimeout);
   
7. }
   
8. DataTable dt = new DataTable();
   
9. dt.Columns.Add("id");
   
10. dt.Columns.Add("PlayerName");
    
11. dt.Columns.Add("Country");
    
12. dt.Columns.Add("OfficerRace");
    
13. dt.Columns.Add("Level");
    
14. dt.Columns.Add("MilitaryRank");
    
15. dt.Columns.Add("Money");
    
16. dt.Columns.Add("ResourceCount");
    
17. dt.Columns.Add("CityCount");
    
18. dt.Columns.Add("GeneralCount");
    
19. dt.Columns.Add("Credit");
    
20. int size = 0;
    
21. IntPtr outArray;
    
22. GetPlayerListCs(20, out size, out outArray);
    
23. tagPlayerInfoOut[] manArray = new tagPlayerInfoOut[size];
    
24. IntPtr current = outArray;
    
25. //Console.WriteLine("记录数{0}",size);
    
26. 
    
27. for( int i = 0; i < size; i++ )
    
28. {
    
29. manArray[ i ] = new tagPlayerInfoOut();
    
30. Marshal.PtrToStructure(current, manArray[i]);
    
31. Marshal.DestroyStructure(current, typeof(tagPlayerInfoOut) );
    
32. current = (IntPtr)((long)current + Marshal.SizeOf(manArray[i]));
    
33. dt.Rows.Add(new object[] {manArray[i].id,manArray[i].PlayerName,manArray[i].Country,manArray[i].OfficerRace,manArray[i].Level,manArray[i].MilitaryRank,manArray[i].Money,manArray[i].ResourceCount,manArray[i].CityCount,manArray[i].GeneralCount,manArray[i].Credit});
    
34. dt.AcceptChanges();
    
35. //Console.WriteLine( "Element {0}: {1} {2}", i, manArray[i].id, manArray[i].PlayerName);
    
36. }
    
37. Marshal.FreeCoTaskMem(outArray);
    
38. return dt;
    
39. }
    
40. public static unsafe DataTable UsingUnsafe()
    
41. {
    
42. int size;
    
43. if(!IsConnection())
    
44. {
    
45. StartWebClient(UDBClientIP,UDBClientPort,UDBClientTimeout);
    
46. }
    
47. DataTable dt = new DataTable();
    
48. dt.Columns.Add("id");
    
49. dt.Columns.Add("PlayerName");
    
50. dt.Columns.Add("Country");
    
51. dt.Columns.Add("OfficerRace");
    
52. dt.Columns.Add("Level");
    
53. dt.Columns.Add("MilitaryRank");
    
54. dt.Columns.Add("Money");
    
55. dt.Columns.Add("ResourceCount");
    
56. dt.Columns.Add("CityCount");
    
57. dt.Columns.Add("GeneralCount");
    
58. dt.Columns.Add("Credit");
    
59. tagPlayerInfoOutEx* pResult;
    
60. GetPlayerListCs(20, out size, &pResult );
    
61. tagPlayerInfoOutEx* pCurrent = pResult;
    
62. //Console.WriteLine("记录数{0}",size);
    
63. for( int i = 0; i < size; i++, pCurrent++ )
    
64. {
    
65. //Console.WriteLine( "Element {0}: {1} {2}", i, pCurrent->id ,Marshal.PtrToStringAnsi(pCurrent->PlayerName));
    
66. //Marshal.FreeCoTaskMem(pCurrent->PlayerName );
    
67. dt.Rows.Add(new object[] {pCurrent->id,pCurrent->PlayerName,pCurrent->Country,pCurrent->OfficerRace,pCurrent->Level,pCurrent->MilitaryRank,pCurrent->Money,pCurrent->ResourceCount,pCurrent->CityCount,pCurrent->GeneralCount,pCurrent->Credit});
    
68. dt.AcceptChanges();
    
69. }
    
70. Marshal.FreeCoTaskMem((IntPtr)pResult );
    
71. return dt;
    
72. }

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