在c#中声明一个指针指向c dll中的非托管结构

时间:2011-09-29 20:47:55

标签: c#

我遇到了一个我两天都无法解决的问题。

错误消息如下所示:

无法获取地址,获取大小或声明指向托管类型的指针 ( 'Control_Vertilon.Imports.PHOTONIQ_CONFIG_TABLE')

以下是代码,

         UInt16[] Arguments = new UInt16[PHOTONIQ_ARG_BUFF_SZ];

         PHOTONIQ_CONFIG_TABLE PhotoniqConfigTable = new PHOTONIQ_CONFIG_TABLE();

        UInt16 *cfgPtr = (UInt16*)&PhotoniqConfigTable;       

        for(int i = 0; i < Imports.CONFIG_TABLE_SZ; i++){
            Arguments[i+1] =  *cfgPtr++; 
        }

        Imports.ControlInterface(Opcode, Arguments, 0x1, Imports.TimeoutMs, ref errInNoErrorStruct, ref NumRetArguments, ref PhotoniqConfigTable, Imports.CONFIG_TABLE_SZ, ref errOutStruct);   

我编组的PhotoniqConfigTable如下所示,

       [StructLayout(LayoutKind.Sequential)]
        unsafe public struct PHOTONIQ_CONFIG_TABLE
        {
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 SystemMode;       //Indicates current system mode, acquire or standby mode 0 = Standby Mode 1 = Acquire Mode
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 HVLimit0;   // Maximum allowed voltage on HV supply 1 Range = 500 ?9250 (50 ?925V)
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 HVLimit1;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 NumChannelsB0;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 NumChannelsB1;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 NumChannelsB2;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 NumChannelsB3;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 HVEnabled;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 HVSetpoint0;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 HVSetpoint1;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 UserConfigID;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 DCRD_AOut_0;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 BandEnables;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 Band0StartIndex;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 Band0StopIndex;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 Band1StartIndex;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 Band1StopIndex;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 Band2StartIndex;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 Band2StopIndex;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 Band3StartIndex;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 Band3StopIndex;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 Band4StartIndex;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 Band4StopIndex;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 Band5StartIndex;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 Band5StopIndex;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 Band6StartIndex;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 Band6StopIndex;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 Band7StartIndex;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 Band7StopIndex;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 FlagEnables;      // pterm flag enables
            [MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 4)]
            public UInt16[] Flag0Operands;  // flag 0 operands: 64 bits
            [MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 4)]
            public UInt16[] Flag1Operands;  // flag 0 operands: 64 bits
            [MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 4)]
            public UInt16[] Flag2Operands;  // flag 0 operands: 64 bits
            [MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 4)]
            public UInt16[] Flag3Operands;  // flag 0 operands: 64 bits
            [MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 4)]
            public UInt16[] Flag4Operands;  // flag 0 operands: 64 bits
            [MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 4)]
            public UInt16[] Flag5Operands;  // flag 0 operands: 64 bits
            [MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 4)]
            public UInt16[] Flag6Operands;  // flag 0 operands: 64 bits
            [MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 4)]
            public UInt16[] Flag7Operands;  // flag 0 operands: 64 bits
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 PTerm0;               // flag 0 - 7 product terms
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 PTerm1;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 PTerm2;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 PTerm3;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 PTerm4;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 PTerm5;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 PTerm6;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 PTerm7;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 DataFilterEnable; // 1 = enable spectral filtering, 0 = disable
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 ProcessingEnables;    // bit 0 = spect filt, bit 1 = gain, 2 = bkgnd sub.
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 TimestampEnable;  // 1 = enable time stamp, 0 = disable
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 DACspare;
            [MarshalAs(UnmanagedType.I4)]
            public Int32 TimestampInterval; //
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 CustomWordsEnable;    // 1/0
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 EventCustomCount; //
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 RESERVED;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 ImageAcqMode;     // 1 = image, 0 = particle
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 InputTrigThresh;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 InputTrigChannel; // 
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 RangeErrorEnable; // 1 = enable range error, 0 = disable
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 CrossBankConfig;  //
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 ReportPackingMode;    //
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 GPOutputEnable;       //
            [MarshalAs(UnmanagedType.I4)]
            public Int32 GPOutputDelay;     //
            [MarshalAs(UnmanagedType.I4)]
            public Int32 GPOutputPeriod;        //
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 IntBoxcarEnable;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 BoxcarWidthEnable;
            [MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 4)]
            public Int32[] ResetDelay;
            [MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 4)]
            public UInt16[] TrigSource;
            [MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 4)]
            public Int32[] TrigPeriod;
            [MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 4)]
            public Int32[] IntegPeriod;
            [MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 4)]
            public Int32[] IntegDelay;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 SibSel0;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 SibSel1;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 SibSel2;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 SibSel3;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 SibSel4;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 SibSel5;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 SibSel6;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 SibSel7;
            [MarshalAs(UnmanagedType.I4)]
            public Int32 TriggerEndCount;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 TrigStampSelect;
            [MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 4)]
            public UInt16[] DataFormat;     // 4 banks: 0 = 17bit sign/mag, 1 = 16bit 2's, comp, 2 = 16b, 2's 1/2 scale
            [MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 7)]
            public UInt16[] RESERVED1;
            [MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 256)]
            public UInt16[] GainArray;
            [MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 256)]
            public UInt16[] TrigThreshArray;
            [MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 16)]
            public UInt16[] TrigEnableArray;    // 256 bits, 1/0 for each channel (max of 256 channels)
            [MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 322)]
            public UInt16[] RESERVED2;          //  678-999
            [MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 250)]
            public UInt16[] CustomArray;            // user custom space: 1000-1249
            [MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 567)]
            public UInt16[] FactoryArray;           // start of factory table
            [MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 32)]
            public SByte[] ModelNumber;         // model number
            [MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 151)]
            public UInt16[] FactoryArray1;      // last piece of factory table
        }  
问题是,我认为我的结构是非托管类型但编译器说它是托管类型。

或者可能是指向这种方式的UInt16指针在托管代码中是错误的。

缓冲区Argument []是16位,这是dll函数中的传递参数,所以无论是使用指针还是缓冲区移动数据,我都坚持使用16位。

如果有人可以帮助解决这个问题,那将是一个巨大的帮助。

我搜索了网页但找不到确切的答案。

提前致谢。

=============================================== ===================================

嗨谢谢你的回复,

我在下面的代码中收到了不同的错误:

        fixed (UInt16 *cfgPtr = (UInt16*)&PhotoniqConfigTable){
            //modify config table, then send it back up to PhotoniQ
            PhotoniqConfigTable.NumChannelsB0 = 6;
            PhotoniqConfigTable.IntegPeriod[0] = per;
            PhotoniqConfigTable.TrigPeriod[0] = 100000;
            PhotoniqConfigTable.TrigStampSelect = 1;
            PhotoniqConfigTable.TimestampEnable = 0;
            PhotoniqConfigTable.RangeErrorEnable = 0;
            PhotoniqConfigTable.DataFormat[0] = 0;
            PhotoniqConfigTable.GPOutputEnable = 1;
            PhotoniqConfigTable.GPOutputDelay = 10;
            PhotoniqConfigTable.GPOutputPeriod = 1000;

            for (int i = 0; i < Imports.CONFIG_TABLE_SZ; i++)
            {
                Arguments[i + 1] = *cfgPtr++;
            }
        }      

错误消息是:

无法分配给'cfgPtr',因为它是'固定变量'。

固定语句分配的右侧可能不是强制转换表达式。

您不能使用未固定表达式中包含的固定大小缓冲区。尝试使用fixed语句。 (不同行的三个相同错误)

任何可以向我解释的人都会给我很大的帮助,因为我没有时间。

结构现在如下所示:

        [StructLayout(LayoutKind.Sequential)]
        unsafe public struct PHOTONIQ_CONFIG_TABLE
        {
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 SystemMode;       //Indicates current system mode, acquire or standby mode 0 = Standby Mode 1 = Acquire Mode
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 HVLimit0;   // Maximum allowed voltage on HV supply 1 Range = 500 ?9250 (50 ?925V)
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 HVLimit1;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 NumChannelsB0;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 NumChannelsB1;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 NumChannelsB2;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 NumChannelsB3;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 HVEnabled;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 HVSetpoint0;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 HVSetpoint1;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 UserConfigID;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 DCRD_AOut_0;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 BandEnables;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 Band0StartIndex;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 Band0StopIndex;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 Band1StartIndex;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 Band1StopIndex;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 Band2StartIndex;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 Band2StopIndex;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 Band3StartIndex;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 Band3StopIndex;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 Band4StartIndex;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 Band4StopIndex;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 Band5StartIndex;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 Band5StopIndex;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 Band6StartIndex;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 Band6StopIndex;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 Band7StartIndex;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 Band7StopIndex;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 FlagEnables;      // pterm flag enables
            //[MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 4)]
            public fixed UInt16 Flag0Operands[4];   // flag 0 operands: 64 bits
            //[MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 4)]
            public fixed UInt16 Flag1Operands[4];   // flag 0 operands: 64 bits
            //[MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 4)]
            public fixed UInt16 Flag2Operands[4];   // flag 0 operands: 64 bits
            //[MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 4)]
            public fixed UInt16 Flag3Operands[4];   // flag 0 operands: 64 bits
            //[MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 4)]
            public fixed UInt16 Flag4Operands[4];   // flag 0 operands: 64 bits
            //[MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 4)]
            public fixed UInt16 Flag5Operands[4];   // flag 0 operands: 64 bits
            //[MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 4)]
            public fixed UInt16 Flag6Operands[4];   // flag 0 operands: 64 bits
            //[MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 4)]
            public fixed UInt16 Flag7Operands[4];   // flag 0 operands: 64 bits
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 PTerm0;               // flag 0 - 7 product terms
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 PTerm1;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 PTerm2;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 PTerm3;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 PTerm4;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 PTerm5;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 PTerm6;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 PTerm7;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 DataFilterEnable; // 1 = enable spectral filtering, 0 = disable
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 ProcessingEnables;    // bit 0 = spect filt, bit 1 = gain, 2 = bkgnd sub.
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 TimestampEnable;  // 1 = enable time stamp, 0 = disable
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 DACspare;
            [MarshalAs(UnmanagedType.I4)]
            public Int32 TimestampInterval; //
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 CustomWordsEnable;    // 1/0
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 EventCustomCount; //
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 RESERVED;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 ImageAcqMode;     // 1 = image, 0 = particle
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 InputTrigThresh;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 InputTrigChannel; // 
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 RangeErrorEnable; // 1 = enable range error, 0 = disable
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 CrossBankConfig;  //
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 ReportPackingMode;    //
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 GPOutputEnable;       //
            [MarshalAs(UnmanagedType.I4)]
            public Int32 GPOutputDelay;     //
            [MarshalAs(UnmanagedType.I4)]
            public Int32 GPOutputPeriod;        //
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 IntBoxcarEnable;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 BoxcarWidthEnable;
            //[MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 4)]
            public fixed Int32 ResetDelay[4];
            //[MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 4)]
            public fixed UInt16 TrigSource[4];
            //[MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 4)]
            public fixed Int32 TrigPeriod[4];
            //[MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 4)]
            public fixed Int32 IntegPeriod[4];
            //[MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 4)]
            public fixed Int32 IntegDelay[4];
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 SibSel0;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 SibSel1;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 SibSel2;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 SibSel3;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 SibSel4;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 SibSel5;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 SibSel6;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 SibSel7;
            [MarshalAs(UnmanagedType.I4)]
            public Int32 TriggerEndCount;
            [MarshalAs(UnmanagedType.U2)]
            public UInt16 TrigStampSelect;
            //[MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 4)]
            public fixed UInt16 DataFormat[4];      // 4 banks: 0 = 17bit sign/mag, 1 = 16bit 2's, comp, 2 = 16b, 2's 1/2 scale
            //[MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 7)]
            public fixed UInt16 RESERVED1[7];
            //[MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 256)]
            public fixed UInt16 GainArray[256];
            //[MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 256)]
            public fixed UInt16 TrigThreshArray[256];
            //[MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 16)]
            public fixed UInt16 TrigEnableArray[16];    // 256 bits, 1/0 for each channel (max of 256 channels)
            //[MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 322)]
            public fixed UInt16 RESERVED2[322];         //  678-999
            //[MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 250)]
            public fixed UInt16 CustomArray[250];           // user custom space: 1000-1249
            //[MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 567)]
            public fixed UInt16 FactoryArray[567];          // start of factory table
            //[MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 32)]
            public fixed SByte ModelNumber[32];         // model number
            //[MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 151)]
            public fixed UInt16 FactoryArray1[151];
            //public fixed UInt16 FactoryArray1[151];       // last piece of factory table
        };  

3 个答案:

答案 0 :(得分:6)

第二个答案,回答你的第二个问题:

  

错误消息是:

Cannot assign to 'cfgPtr' because it is a 'fixed variable'.

The right hand side of a fixed statement assignment may not be a cast expression.

You cannot use fixed size buffers contained in unfixed expressions. Try using the fixed statement. 

错误消息告诉您出了什么问题。阅读它们。

  

无法分配给'cfgPtr',因为它是'固定变量'。

你在这里分配:

Arguments[i + 1] = *cfgPtr++;

初始化包含指向空间固定块的指针的变量后,您无法更改该变量,因为您可能正在将其更改为指向未固定的空间块。为了防止这种常见错误,C#阻止您修改该变量。

如果要修改变量,创建另一个变量。将其设置为cfgPtr,然后修改那个变量。确保你做得正确;你现在负责确保指针指向固定的东西。

The right hand side of a fixed statement assignment may not be a cast expression.

在我的上一个回答中,我告诉你要阅读规范的第18.7节,其中规定“固定”声明需要:

  

引用可移动变量的固定大小缓冲区成员的简单名称或成员访问

演员表达不是“简单名称或成员访问”。强制转换表达式是强制转换表达式。这个演员阵容甚至没有意义!指向结构的指针不是指向ushort的指针!

移除演员。将初始化程序中的表达式更改为对可移动变量的固定大小缓冲区成员的成员访问权。

You cannot use fixed size buffers contained in unfixed expressions. Try using the fixed statement.

您直接使用固定大小的缓冲区。 您不能这样做。您只能通过获取指向它的指针来使用固定大小的缓冲区。同样,这是安全系统的一部分,可确保您不会意外地访问非固定的固定大小的缓冲区。停止尝试直接访问缓冲区。获取指向缓​​冲区的指针并通过指针访问它。

  

任何可以向我解释的人都会给我很大的帮助,因为我没有时间。

让我在这一点上非常清楚:您已关闭托管安全系统,程序的正确性和流程的稳定性现在是您的问题,而不是托管运行时的问题。如果您不理解所有关于如何安全地管理自己的指针,停止您正在做的事情并阅读它,直到您理解它为止。现在急于编写一大堆您不理解的代码,您可能不得不在以后处理可怕的错误。现在不是匆忙的时候。

首先阅读第18章的全部内容。只有当你彻底了解所有这些内容时,才应该尝试编写复杂的不安全代码。

答案 1 :(得分:5)

您已经说过如何在非托管内存中布局数组,但尚未说明如何在托管内存中布局它们。因此,编译器认为在该结构中有一堆对垃圾收集的托管内存的引用 - 所有这些数组 - 并且不会让你将结果指向它。

我怀疑你希望那些数组是固定大小的缓冲区,而不是托管数组,是吗?

您需要阅读C#规范第18.7节,以了解固定大小的缓冲区如何在结构中工作。

另请注意there is a big difference between a "fixed in size" array and a "fixed in place" object pointed to by a pointer;这些是“固定”一词的两个完全不同的用法。许多人让他们感到困惑,特别是因为要正确安全地使用“固定大小”缓冲区,缓冲区的内存必须“固定到位”。

答案 2 :(得分:1)

而不是

        [MarshalAsAttribute(UnmanagedType.ByValArray, SizeConst = 151)]
        public UInt16[] FactoryArray1;

        public unsafe fixed ushort FactoryArray1[151];

因为在托管和非托管内存中数组“看起来”不同,但固定大小的缓冲区“看起来”相同(即可以闪烁)。