C # Try to read or write the protected memory. This usually indicates that other memory is damaged.

When someone else's DLL is called in C #, sometimes some attempt is made to read or write the protected memory. This usually indicates that other memory is damaged.

The pointer is used when the value is passed, and then the conversion is done in C.

Solution:

[DllImport ("APPLISTCC. dll")]
Public static extern string TestFunc1 (string param1 );

String ret1 = TestFunc1 ("text ");

Changed:

[DllImport ("APPLISTCC. dll")]
Public static extern IntPtr TestFunc1 (IntPtr par1 );

IntPtr ptrIn = Marshal. StringToHGlobalAnsi ("text ");
IntPtr ptrRet = TestFunc1 (ptrIn );
String retlust = Marshal. PtrToStringAnsi (ptrRet );