CODEWITHSUNDEEP
c#c++unions
Jonatan Acahú
Jonatan Acahú

Reputation: 11

Union Struct C# - Equivalent Or Equals?

see struct below

struct STRUCT_ITEM
{

short Index;

    union
    {
        short Value;

        struct
        {
            unsigned char Type;
            unsigned char Values;
        };

    } Effect[3];
};

Hello .. Good evening. I would like if it is possible to convert a structure in C ++ to C #? I would like the new structure to contain the array of 3 objects, as you can see in the code in C ++.

Is to be used like this:

var Item = new Item ();

Item.Effect [2] .Type = 2;

I just get it that way:

    [FieldOffset(0)]
    public short Index;

    [FieldOffset(2)]
    public short MountHP;

    [FieldOffset(2)]
    public byte EF1;

    [FieldOffset(3)]
    public byte EFV1;

    [FieldOffset(4)]
    public byte EF2;

    [FieldOffset(5)]
    public byte EFV2;

    [FieldOffset(6)]
    public byte EF3;

    [FieldOffset(7)]
    public byte EFV3;

Is it possible to contain array in the structure? This structure contains the maximum size of 8 bytes.

Who can help, I am grateful! Thank you so much

Upvotes: 1

Views: 2198

Answers (1)

Jake
Jake

Reputation: 139

Try this. and Yes, The array can use in Sturcture.

    [StructLayout(LayoutKind.Explicit)]
    public struct STRUCT_SUB_ITEM
    {
        [FieldOffset(0)]
        public short Value;
        [FieldOffset(0)]
        public byte Type;
        [FieldOffset(1)]
        public byte Values;
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct STRUCT_ITEM
    {
        short index;
        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 3)]
        public STRUCT_SUB_ITEM[] Effect;
    }

and Test just like this.

    static void test3()
    {
        STRUCT_ITEM item = new STRUCT_ITEM();
        item.Effect = new STRUCT_SUB_ITEM[3];

        item.Effect[0].Type = 1;
        item.Effect[0].Values = 2;

        item.Effect[1].Type = 1;
        item.Effect[1].Values = 2;

        item.Effect[2].Type = 1;
        item.Effect[2].Values = 2;

        Console.WriteLine(item.Effect[2].Value);
    }

And an Array with restrict types (bool, int, double, ... ) Using Fixed keyword, it dosen't need alloc memory.

    [StructLayout(LayoutKind.Explicit, CharSet = CharSet.Ansi)]
    public unsafe struct STRUCT_ITEM2
    {
        [FieldOffset(0)]
        public fixed byte item_01[260];
    }

Upvotes: 2

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