如何在 C# 中声明 LARGE_INTEGER

Question

下面的代码（C++ 中）是我尝试转换为 C# 的代码。

DWORD Func_X_4(DWORD arg1, DWORD arg2, DWORD arg3)
{
LARGE_INTEGER result = {1, 0};
LARGE_INTEGER temp1 = {0};
LARGE_INTEGER temp2 = {0};
LARGE_INTEGER temp3 = {0};
LARGE_INTEGER temp4 = {0};
for(int x = 0; x < 32; ++x)
{
    if(arg2 & 1)
    {
        temp1.LowPart = arg3;
        temp1.HighPart = 0;
        temp2.QuadPart = temp1.QuadPart * result.QuadPart;
        temp3.LowPart = arg1;
        temp3.HighPart = 0;
        temp4.QuadPart = temp2.QuadPart % temp3.QuadPart;
        result.QuadPart = temp4.QuadPart;
    }
    arg2 >>= 1;
    temp1.LowPart = arg3;
    temp1.HighPart = 0;
    temp1.QuadPart *= temp1.QuadPart;
    temp2.LowPart = arg1;
    temp2.HighPart = 0;
    temp3.QuadPart = temp1.QuadPart % temp2.QuadPart;
    arg3 = temp3.LowPart;
    if(!arg2)
        break;
}
return result.LowPart;
}

这里我尝试翻译代码，但它太混乱了，而且我以前从未使用过大整数。

结构：

public struct LARGE_INTEGER
{
    UInt32 LowPart;
    Int32 HighPart;
    Int32 QuadPart;
}

翻译后的功能：

    public Int32 Func_X_4(Int32 arg1, Int32 arg2, Int32 arg3)
    {
    LARGE_INTEGER result = {1, 0}; //this and the four below,are they correct?
    LARGE_INTEGER temp1 = {0, 0};
    LARGE_INTEGER temp2 = {0, 0};
    LARGE_INTEGER temp3 = {0, 0};
    LARGE_INTEGER temp4 = {0, 0};
    for(int x = 0; x < 32; ++x)
    {
        if(arg2 & 1==0) //correct?
        {
            temp1.LowPart = arg3;
            temp1.HighPart = 0;
            temp2.QuadPart = temp1.QuadPart * result.QuadPart;
            temp3.LowPart = arg1;
            temp3.HighPart = 0;
            temp4.QuadPart = temp2.QuadPart % temp3.QuadPart;
            result.QuadPart = temp4.QuadPart;
        }
        arg2 >>= 1;
        temp1.LowPart = arg3;
        temp1.HighPart = 0;
        temp1.QuadPart *= temp1.QuadPart;
        temp2.LowPart = arg1;
        temp2.HighPart = 0;
        temp3.QuadPart = temp1.QuadPart % temp2.QuadPart;
        arg3 = temp3.LowPart;
        if(arg2 != 0) //correct?
        break;
    }
    return result.LowPart;
}

问题： 第一个问题是我在C#中没有找到LARGE_INTEGER类型变量，所以我创建了一个结构，我想知道是否确实存在。 至于第二个问题，功能不对，没有任何作用。

对于该特定问题的任何帮助将不胜感激！ 先感谢您。

Answer 1

LARGE_INTEGER 结构的直接翻译是：

[StructLayout(LayoutKind.Explicit, Size=8)]
struct LARGE_INTEGER
{
    [FieldOffset(0)]public Int64 QuadPart;
    [FieldOffset(0)]public UInt32 LowPart;
    [FieldOffset(4)]public Int32 HighPart;
}

它就像 C 中的联合，其中 QuadPart 是一个 8 字节值，LowPart 占用前 4 个字节和 HighPart 占据高 4 个字节。

Answer 2

它是 Int64。 基于 http://msdn.microsoft.com/en-us/library/ aa383713.aspx，它是一个 64 位有符号整数。

Answer 3

基于之前的答案，我发现扩展 LARGE_INTEGER 的定义以包括高位和低位部分的 int 和 uint 版本很有用：

[StructLayout(LayoutKind.Explicit, Size=8)]
struct LARGE_INTEGER
    {
    [FieldOffset(0)]public long QuadPart;

    [FieldOffset(0)]public uint LowPart;
    [FieldOffset(4)]public int HighPart;

    [FieldOffset(0)]public int LowPartAsInt;
    [FieldOffset(0)]public uint LowPartAsUInt;

    [FieldOffset(4)]public int HighPartAsInt;
    [FieldOffset(4)]public uint HighPartAsUInt;
    }