ArgumentException：指定的结构必须是 blittable 或具有布局信息

Question

近一个星期以来，我一直在拉扯我的头发，试图让它发挥作用。已经解决了几个问题，现在当我尝试将 IntPtr 转换为 DSP_DESCRIPTION 结构时，我遇到了这个新错误。

谁能给我点灯？提前谢谢你们，你们太棒了！

我是否需要切换到不安全模式，因为 FMOD DSP_STRUCTURE 不是 blittable？我将结构的定义放在最后。

**ArgumentException: The specified structure must be blittable or have layout information.**

我从调用静态库函数中获取 IntPtr。

静态库代码 (C++)：

extern "C"
{    
    F_DECLSPEC F_DLLEXPORT int F_STDCALL AigooGetDSPDescription2(FMOD_DSP_DESCRIPTION **ppFmodDesc)
    {

        // defines the user interface, maximum distance knob
        static float distance_mapping_values[] = { 0, 1, 5, 20, 100, 500, 10000 };
        static float distance_mapping_scale[] = { 0, 1, 2, 3, 4, 4.5, 5 };

        FMOD_DSP_INIT_PARAMDESC_FLOAT_WITH_MAPPING(p_max_distance,
        "Max Dist4", "", "Distance at which bandpass stops narrowing. 0 to 1000000000. Default = 100",AIGOO_SIMPLE_PLUGIN_PARAM_MAX_DISTANCE_DEFAULT, distance_mapping_values,
        distance_mapping_scale);


        // defines the 3D location attributes
        FMOD_DSP_INIT_PARAMDESC_DATA(p_3d_attributes,       "3D Attributes", "",    "",                                                                           FMOD_DSP_PARAMETER_DATA_TYPE_3DATTRIBUTES);

        FMOD_DSP_DESCRIPTION* Aigoo_Simple_Plugin_DescPtr = new FMOD_DSP_DESCRIPTION ();


            Aigoo_Simple_Plugin_DescPtr->pluginsdkversion = FMOD_PLUGIN_SDK_VERSION;
            strcpy(Aigoo_Simple_Plugin_DescPtr->name,"AigooSimplePlugin6");
            Aigoo_Simple_Plugin_DescPtr->version = 0x00010000;     // plug-in version
            Aigoo_Simple_Plugin_DescPtr->numinputbuffers = 1;      // number of input buffers to process
            Aigoo_Simple_Plugin_DescPtr->numoutputbuffers = 1;     // number of output buffers to process
            Aigoo_Simple_Plugin_DescPtr->create = Aigoo_Simple_Plugin_dspcreate;
            Aigoo_Simple_Plugin_DescPtr->release = Aigoo_Simple_Plugin_dsprelease;
            Aigoo_Simple_Plugin_DescPtr->reset = Aigoo_Simple_Plugin_dspreset;
            Aigoo_Simple_Plugin_DescPtr->read = Aigoo_Simple_Plugin_dspread;
            Aigoo_Simple_Plugin_DescPtr->process = 0;
            Aigoo_Simple_Plugin_DescPtr->setposition = 0;
            Aigoo_Simple_Plugin_DescPtr->numparameters = AIGOO_SIMPLE_PLUGIN_NUM_PARAMETERS;
            Aigoo_Simple_Plugin_DescPtr->paramdesc = Aigoo_Simple_Plugin_dspparam;
            Aigoo_Simple_Plugin_DescPtr->setparameterfloat = Aigoo_Simple_Plugin_dspsetparamfloat;
            Aigoo_Simple_Plugin_DescPtr->setparameterint = 0, // Aigoo_Simple_Plugin_dspsetparamint;
            Aigoo_Simple_Plugin_DescPtr->setparameterbool = 0, // Aigoo_Simple_Plugin_dspsetparambool;
            Aigoo_Simple_Plugin_DescPtr->setparameterdata = Aigoo_Simple_Plugin_dspsetparamdata;
            Aigoo_Simple_Plugin_DescPtr->getparameterfloat = Aigoo_Simple_Plugin_dspgetparamfloat;
            Aigoo_Simple_Plugin_DescPtr->getparameterint = 0, // Aigoo_Simple_Plugin_dspgetparamint;
            Aigoo_Simple_Plugin_DescPtr->getparameterint = 0, // Aigoo_Simple_Plugin_dspgetparambool;
            Aigoo_Simple_Plugin_DescPtr->getparameterdata = Aigoo_Simple_Plugin_dspgetparamdata;
            Aigoo_Simple_Plugin_DescPtr->shouldiprocess = Aigoo_Simple_Plugin_shouldiprocess;
            Aigoo_Simple_Plugin_DescPtr->userdata = 0;       // userdata
            Aigoo_Simple_Plugin_DescPtr->sys_register = Aigoo_Simple_Plugin_sys_register;
            Aigoo_Simple_Plugin_DescPtr->sys_deregister = Aigoo_Simple_Plugin_sys_deregister;
            Aigoo_Simple_Plugin_DescPtr->sys_mix = Aigoo_Simple_Plugin_sys_mix;

        *ppFmodDesc = Aigoo_Simple_Plugin_DescPtr;


        return 9291983;
    }
}

应用程序 (C#)：

我正在使用 Unity3d (C#) 进行编码并生成 iOS 项目。为 iOS 使用静态库 (*.a)。

public class FMOD_Listener : MonoBehaviour 
{
...
    void LoadPlugins()
    {
        //cchacon
        uint mmdsp_handle; //handler for the plugin

        FMOD.System sys = null;
        ERRCHECK(FMOD_StudioSystem.instance.System.getLowLevelSystem(out sys));
        int plugin_result = 0;

        if (Application.platform == RuntimePlatform.IPhonePlayer) {

            IntPtr FmodDescIntPtr;
            plugin_result = FMODPlugInHandler.AigooGetDSPDescription2(out FmodDescIntPtr);
            myLog = "plugin_result = " + plugin_result + " FmodDescIntPtr: " + FmodDescIntPtr; 
            Camera.main.backgroundColor = Color.blue;

            if (FmodDescIntPtr != IntPtr.Zero)
            {
                plugin_result = 838383;
                myLog = "plugin_result = " + plugin_result  + " FmodDescIntPtr: " + FmodDescIntPtr ; 
                Camera.main.backgroundColor = Color.yellow;

                DSP_DESCRIPTION FmodDesc = (DSP_DESCRIPTION)Marshal.PtrToStructure(FmodDescIntPtr, typeof(DSP_DESCRIPTION));

                plugin_result = 889911;
                myLog = "plugin_result = " + plugin_result ; 
                Camera.main.backgroundColor = Color.gray;

                ERRCHECK(sys.registerDSP(ref FmodDesc, out mmdsp_handle));

                plugin_result = 123456;
                myLog = "plugin_result = " + plugin_result ; 
                Camera.main.backgroundColor = Color.green;

            }
            else
                Console.WriteLine("FmodDescPtr is IntPtr.Zero");

        }

        if (Application.platform == RuntimePlatform.IPhonePlayer && pluginPaths.Length != 0)
        {
            FMOD.Studio.UnityUtil.LogError("DSP Plugins not currently supported on iOS, contact support@fmod.org for more information");
            return;
        }

        foreach (var name in pluginPaths)
        {
            var path = pluginPath + "/" + GetPluginFileName(name);

            FMOD.Studio.UnityUtil.Log("Loading plugin: " + path);

#if !UNITY_METRO
            if (!System.IO.File.Exists(path))
            {
                FMOD.Studio.UnityUtil.LogWarning("plugin not found: " + path);
            }
#endif

            uint handle;
            ERRCHECK(sys.loadPlugin(path, out handle));

        }
    }   

...

}

下面是结构体的定义：

[StructLayout(LayoutKind.Sequential)]
public struct DSP_DESCRIPTION
{
    public uint pluginsdkversion;                          /* [w] The plugin SDK version this plugin is built for.  set to this to FMOD_PLUGIN_SDK_VERSION defined above. */
    [MarshalAs(UnmanagedType.ByValArray, SizeConst = 32)]
    public char[]                      name;               /* [w] Name of the unit to be displayed in the network. */
    public uint                        version;            /* [w] Plugin writer's version number. */
    public int                         numinputbuffers;    /* [w] Number of input buffers to process.  Use 0 for DSPs that only generate sound and 1 for effects that process incoming sound. */
    public int                         numoutputbuffers;   /* [w] Number of audio output buffers.  Only one output buffer is currently supported. */
    public DSP_CREATECALLBACK          create;             /* [w] Create callback.  This is called when DSP unit is created.  Can be null. */
    public DSP_RELEASECALLBACK         release;            /* [w] Release callback.  This is called just before the unit is freed so the user can do any cleanup needed for the unit.  Can be null. */
    public DSP_RESETCALLBACK           reset;              /* [w] Reset callback.  This is called by the user to reset any history buffers that may need resetting for a filter, when it is to be used or re-used for the first time to its initial clean state.  Use to avoid clicks or artifacts. */
    public DSP_READCALLBACK            read;               /* [w] Read callback.  Processing is done here.  Can be null. */
    public DSP_PROCESS_CALLBACK        process;            /* [w] Process callback.  Can be specified instead of the read callback if any channel format changes occur between input and output.  This also replaces shouldiprocess and should return an error if the effect is to be bypassed.  Can be null. */
    public DSP_SETPOSITIONCALLBACK     setposition;        /* [w] Setposition callback.  This is called if the unit wants to update its position info but not process data.  Can be null. */

    public int                         numparameters;      /* [w] Number of parameters used in this filter.  The user finds this with DSP::getNumParameters */
    public IntPtr                      paramdesc;          /* [w] Variable number of parameter structures. */
    public DSP_SETPARAM_FLOAT_CALLBACK setparameterfloat;  /* [w] This is called when the user calls DSP.setParameterFloat. Can be null. */
    public DSP_SETPARAM_INT_CALLBACK   setparameterint;    /* [w] This is called when the user calls DSP.setParameterInt.   Can be null. */
    public DSP_SETPARAM_BOOL_CALLBACK  setparameterbool;   /* [w] This is called when the user calls DSP.setParameterBool.  Can be null. */
    public DSP_SETPARAM_DATA_CALLBACK  setparameterdata;   /* [w] This is called when the user calls DSP.setParameterData.  Can be null. */
    public DSP_GETPARAM_FLOAT_CALLBACK getparameterfloat;  /* [w] This is called when the user calls DSP.getParameterFloat. Can be null. */
    public DSP_GETPARAM_INT_CALLBACK   getparameterint;    /* [w] This is called when the user calls DSP.getParameterInt.   Can be null. */
    public DSP_GETPARAM_BOOL_CALLBACK  getparameterbool;   /* [w] This is called when the user calls DSP.getParameterBool.  Can be null. */
    public DSP_GETPARAM_DATA_CALLBACK  getparameterdata;   /* [w] This is called when the user calls DSP.getParameterData.  Can be null. */
    public DSP_SHOULDIPROCESS_CALLBACK shouldiprocess;     /* [w] This is called before processing.  You can detect if inputs are idle and return FMOD_OK to process, or any other error code to avoid processing the effect.  Use a count down timer to allow effect tails to process before idling! */
    public IntPtr                      userdata;           /* [w] Optional. Specify 0 to ignore. This is user data to be attached to the DSP unit during creation.  Access via DSP::getUserData. */
}

这里定义了一些回调，供参考。

public delegate RESULT DSP_CREATECALLBACK           (ref DSP_STATE dsp_state);
public delegate RESULT DSP_RELEASECALLBACK          (ref DSP_STATE dsp_state);
public delegate RESULT DSP_RESETCALLBACK            (ref DSP_STATE dsp_state);
public delegate RESULT DSP_SETPOSITIONCALLBACK      (ref DSP_STATE dsp_state, uint pos);
public delegate RESULT DSP_READCALLBACK             (ref DSP_STATE dsp_state, IntPtr inbuffer, IntPtr outbuffer, uint length, int inchannels, ref int outchannels);
public delegate RESULT DSP_SHOULDIPROCESS_CALLBACK  (ref DSP_STATE dsp_state, bool inputsidle, uint length, CHANNELMASK inmask, int inchannels, SPEAKERMODE speakermode);
public delegate RESULT DSP_PROCESS_CALLBACK         (ref DSP_STATE dsp_state, uint length, ref DSP_BUFFER_ARRAY inbufferarray, ref DSP_BUFFER_ARRAY outbufferarray, bool inputsidle, DSP_PROCESS_OPERATION op);
public delegate RESULT DSP_SETPARAM_FLOAT_CALLBACK  (ref DSP_STATE dsp_state, int index, float value);
public delegate RESULT DSP_SETPARAM_INT_CALLBACK    (ref DSP_STATE dsp_state, int index, int value);
public delegate RESULT DSP_SETPARAM_BOOL_CALLBACK   (ref DSP_STATE dsp_state, int index, bool value);
public delegate RESULT DSP_SETPARAM_DATA_CALLBACK   (ref DSP_STATE dsp_state, int index, IntPtr data, uint length);
public delegate RESULT DSP_GETPARAM_FLOAT_CALLBACK  (ref DSP_STATE dsp_state, int index, ref float value, IntPtr valuestr);
public delegate RESULT DSP_GETPARAM_INT_CALLBACK    (ref DSP_STATE dsp_state, int index, ref int value, IntPtr valuestr);
public delegate RESULT DSP_GETPARAM_BOOL_CALLBACK   (ref DSP_STATE dsp_state, int index, ref bool value, IntPtr valuestr);
public delegate RESULT DSP_GETPARAM_DATA_CALLBACK   (ref DSP_STATE dsp_state, int index, ref IntPtr data, ref uint length, IntPtr valuestr);

Answer 1

这里的问题是委托不是 blittable。我们已经解决了这个问题：here