Question

下面的代码（在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;
}

在这里，我尝试翻译代码，但它太乱了，我之前从未使用过大整数。

结构：

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

翻译功能：

    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：第一个问题是我没有在C＃中找到一个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，没有用。

对这个特定问题的任何帮助都将非常感谢！提前谢谢。

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字节的值，LowPart占据前4个字节而HighPart占据高位4个字节。

Answer 2

其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

在前一个答案的基础上，我发现扩展LARGE_INTEGER的定义以包含高和低部分的int和uint版本是有用的：

[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;
    }

如何在C＃中声明LARGE INTEGER

3 个答案: