如何访问C＃函数，它将指针作为C＃的输入参数

Question

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.InteropServices;

namespace PatternSequencer
{
    class Version
    {
        public string majorVersion;
        public string minorVersion;

        ushort* pmajorVersion;
        ushort* pminorVersion;
        ulong status;

        [DllImport(@"c:\DOcuments\Myapp.dll", CallingConvention = CallingConvention.Cdecl, EntryPoint = "SRX_DllVersion")]
        public static extern ulong SRX_DllVersion(ushort* pmajorVersion, ushort* pminorVersion);


        public Version()
        {
            status = SRX_DllVersion(&pmajorVersion, &pminorVersion);
            if (status)
            {
                majorVersion = "1 - " + *pmajorVersion;
                minorVersion = "1 - " + *pminorVersion;
            }
            else
            {
                majorVersion = "0 - " + *pmajorVersion;
                minorVersion = "0 - " + *pminorVersion;
            }
        }
    }
}

它会抛出错误指针，固定大小的缓冲区只能在不安全的上下文中使用。 如何将指针传递给C ++ DLL？ 我是C＃的新手，请帮助我

Answer 1

而不是使用unsafe上下文尝试：

[DllImport(@"c:\FreeStyleBuild\BERTScope\Release\Bin\BitAlyzerDLL.dll", CallingConvention = CallingConvention.Cdecl, EntryPoint = "SRX_DllVersion")]
public static extern ulong SRX_DllVersion(out ushort pmajorVersion, out ushort pminorVersion);

拨打电话：

ushort major, minor;
SRX_DllVersion(out major, out minor);

我假设SRX_DllVersion参数仅输出，如果不改变out到ref 。

尽可能避免使用unsafe代码。

Answer 2

当然，你要标记这个类是unsafe ，以使它工作。

unsafe class Version
{
    [DllImport(@"c:\FreeStyleBuild\BERTScope\Release\Bin\BitAlyzerDLL.dll", CallingConvention = CallingConvention.Cdecl, EntryPoint = "SRX_DllVersion")]
     public static extern ulong SRX_DllVersion(ushort* pmajorVersion, ushort* pminorVersion);
}

如果您只有一种方法，则可以将该方法标记为unsafe 。

并且不要忘记打开“允许不安全的代码”编译器选项。

Answer 3

您必须将该方法标记为unsafe

[DllImport(@"c:\FreeStyleBuild\BERTScope\Release\Bin\BitAlyzerDLL.dll", CallingConvention = CallingConvention.Cdecl, EntryPoint = "SRX_DllVersion")]
public static extern ulong SRX_DllVersion(out ushort pmajorVersion, out ushort pminorVersion);

Answer 4

尝试使用unsafe阻止。 更多关于不安全的 。