整数转换字符串之十进制
首先声明，.net自带的ToString方法很好用，也很强大。但我个人基本上只用过最简单的方式，即无参的ToString()函数。关注性能的你也许会发现ToString是个高消费品，但是很多时候又不得不用。想要用得更舒心，那就自食其力吧。
我们知道普通的十进制转换就是一个对10求余取模的循环，而求余取模对于CPU相对于其他运算来说是一件吃力的事情。而对于常数的求余取模一般都可以转换为乘法运算。思路有了，开始敲代码，经过大量Copy、Paste，终于将byte,sbyte,short,ushort,int,uint,long,ulong各个击破。
public const uint div10_16Mul = ((1 << 19) + 9) / 10; public const int div10_16Shift = 19; public const ulong div10000Mul = ((1L << 45) + 9999) / 10000; public const int div10000Shift = 45; public const ulong div100000000Mul = ((1L << 58) + 99999999) / 100000000; public const int div100000000Shift = 58; public unsafe static string toString(this byte value) { if (value >= 100) { char* chars = stackalloc char[4]; int value10 = (value * (int)showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; chars[2] = (char)((value - value10 * 10) + '0'); int value100 = (value10 * (int)showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(int*)chars = ((value10 - value100 * 10) << 16) | value100 | 0x300030; return new string(chars, 0, 3); } else if (value >= 10) { char* chars = stackalloc char[2]; int value10 = (value * (int)showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(int*)chars = ((value - value10 * 10) << 16) | value10 | 0x300030; return new string(chars, 0, 2); } return new string((char)(value + '0'), 1); } public unsafe static string toString(this sbyte value) { if (value >= 0) { if (value >= 100) { char* chars = stackalloc char[3]; value -= 100; *chars = '1'; int value10 = (value * (int)showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(int*)(chars + 1) = ((value - value10 * 10) << 16) | value10 | 0x300030; return new string(chars, 0, 3); } else if (value >= 10) { char* chars = stackalloc char[2]; int value10 = (value * (int)showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(int*)chars = ((value - value10 * 10) << 16) | value10 | 0x300030; return new string(chars, 0, 2); } return new string((char)(value + '0'), 1); } else { int value32 = -value; if (value32 >= 100) { char* chars = stackalloc char[4]; value32 -= 100; *(int*)chars = '-' + ('1' << 16); int value10 = (value32 * (int)showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(int*)(chars + 2) = ((value32 - value10 * 10) << 16) | value10 | 0x300030; return new string(chars, 0, 4); } else if (value32 >= 10) { char* chars = stackalloc char[3]; *chars = '-'; int value10 = (value32 * (int)showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(int*)(chars + 1) = ((value32 - value10 * 10) << 16) | value10 | 0x300030; return new string(chars, 0, 3); } else { char* chars = stackalloc char[2]; *(int*)chars = '-' + ((value32 + '0') << 16); return new string(chars, 0, 2); } } } public unsafe static string toString(this ushort value) { if (value >= 10000) { char* chars = stackalloc char[5]; int value10 = (int)((uint)(value * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift); int value100 = (value10 * (int)showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(int*)(chars + 3) = ((value - value10 * 10) << 16) | (value10 - value100 * 10) | 0x300030; value10 = (value100 * (int)showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; value = (ushort)((value10 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift); *(int*)(chars + 1) = ((value100 - value10 * 10) << 16) | (value10 - value * 10) | 0x300030; *chars = (char)(value + '0'); return new string(chars, 0, 5); } else if (value >= 100) { char* chars = stackalloc char[4]; int value10 = (value * (int)showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; if (value >= 1000) { int value100 = (value10 * (int)showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(int*)(chars + 2) = ((value - value10 * 10) << 16) | (value10 - value100 * 10) | 0x300030; value10 = (value100 * (int)showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(int*)chars = ((value100 - value10 * 10) << 16) | value10 | 0x300030; return new string(chars, 0, 4); } else { chars[2] = (char)((value - value10 * 10) + '0'); int value100 = (value10 * (int)showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(int*)chars = ((value10 - value100 * 10) << 16) | value100 | 0x300030; return new string(chars, 0, 3); } } else if (value >= 10) { char* chars = stackalloc char[2]; int value10 = (value * (int)showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(int*)chars = ((value - value10 * 10) << 16) | value10 | 0x300030; return new string(chars, 0, 2); } return new string((char)(value + '0'), 1); } public unsafe static string toString(this short value) { if (value >= 0) return toString((ushort)value); int value32 = -value; if (value32 >= 10000) { char* chars = stackalloc char[6]; int value10 = (int)((uint)(value32 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift); int value100 = (value10 * (int)showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(int*)(chars + 4) = ((value32 - value10 * 10) << 16) | (value10 - value100 * 10) | 0x300030; value10 = (value100 * (int)showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; value32 = (value10 * (int)showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(int*)(chars + 2) = ((value100 - value10 * 10) << 16) | (value10 - value32 * 10) | 0x300030; *(int*)chars = '-' + ((value32 + '0') << 16); return new string(chars, 0, 6); } else if (value32 >= 100) { if (value32 >= 1000) { char* chars = stackalloc char[5]; *chars = '-'; int value10 = (value32 * (int)showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; int value100 = (value10 * (int)showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(int*)(chars + 3) = ((value32 - value10 * 10) << 16) | (value10 - value100 * 10) | 0x300030; value10 = (value100 * (int)showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(int*)(chars + 1) = ((value100 - value10 * 10) << 16) | value10 | 0x300030; return new string(chars, 0, 5); } else { char* chars = stackalloc char[4]; int value10 = (value32 * (int)showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; int value100 = (value10 * (int)showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(int*)(chars + 2) = ((value32 - value10 * 10) << 16) | (value10 - value100 * 10) | 0x300030; *(int*)chars = '-' + ((value100 + '0') << 16); return new string(chars, 0, 4); } } else if (value32 >= 10) { char* chars = stackalloc char[3]; *chars = '-'; int value10 = (value32 * (int)showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(int*)(chars + 1) = ((value32 - value10 * 10) << 16) | value10 | 0x300030; return new string(chars, 0, 3); } else { char* chars = stackalloc char[2]; *(int*)chars = '-' + ((value32 + '0') << 16); return new string(chars, 0, 2); } } public unsafe static string toString(this uint value) { if (value >= 100000000) { char* chars = stackalloc char[10]; uint value100000000 = (uint)((value * (ulong)showjim.sys.number.div100000000Mul) >> showjim.sys.number.div100000000Shift); value -= value100000000 * 100000000; uint value10000 = (uint)((value * showjim.sys.number.div10000Mul) >> showjim.sys.number.div10000Shift); ToString(value10000, chars + 2); ToString(value - value10000 * 10000, chars + 6); if (value100000000 >= 10) { value10000 = (value100000000 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)chars = ((value100000000 - value10000 * 10) << 16) | value10000 | 0x300030U; return new string(chars, 0, 10); } *++chars = (char)(value100000000 + '0'); return new string(chars, 0, 9); } return ToString99999999(value); } private unsafe static string ToString99999999(uint value) { if (value >= 10000) { char* chars = stackalloc char[8]; uint value10000 = (uint)((value * showjim.sys.number.div10000Mul) >> showjim.sys.number.div10000Shift); if (value10000 >= 100) { uint value10 = (value10000 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; if (value10000 >= 1000) { ToString(value - value10000 * 10000, chars + 4); value = (value10 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)(chars + 2) = ((value10000 - value10 * 10) << 16) | (value10 - value * 10) | 0x300030U; value10 = (value * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)chars = ((value - value10 * 10) << 16) | value10 | 0x300030U; return new string(chars, 0, 8); } else { ToString(value - value10000 * 10000, chars + 3); chars[2] = (char)((value10000 - value10 * 10) + '0'); value = (value10 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)chars = ((value10 - value * 10) << 16) | value | 0x300030U; return new string(chars, 0, 7); } } else if (value10000 >= 10) { ToString(value - value10000 * 10000, chars + 2); value = (value10000 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)chars = ((value10000 - value * 10) << 16) | value | 0x300030U; return new string(chars, 0, 6); } ToString(value - value10000 * 10000, chars + 1); chars[0] = (char)(value10000 + '0'); return new string(chars, 0, 5); } else if (value >= 100) { char* chars = stackalloc char[4]; uint value10 = (value * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; if (value >= 1000) { uint value100 = (value10 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)(chars + 2) = ((value - value10 * 10) << 16) | (value10 - value100 * 10) | 0x300030U; value10 = (value100 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)chars = ((value100 - value10 * 10) << 16) | value10 | 0x300030U; return new string(chars, 0, 4); } else { chars[2] = (char)((value - value10 * 10) + '0'); uint value100 = (value10 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)chars = ((value10 - value100 * 10) << 16) | value100 | 0x300030U; return new string(chars, 0, 3); } } else if (value >= 10) { char* chars = stackalloc char[2]; uint value10 = (value * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)chars = ((value - value10 * 10) << 16) | value10 | 0x300030U; return new string(chars, 0, 2); } return new string((char)(value + '0'), 1); } public unsafe static string toString(this int value) { if (value >= 0) return toString((uint)value); uint value32 = (uint)-value; if (value32 >= 100000000) { char* chars = stackalloc char[12]; uint value100000000 = (uint)((value32 * (ulong)showjim.sys.number.div100000000Mul) >> showjim.sys.number.div100000000Shift); value32 -= value100000000 * 100000000; uint value10000 = (uint)((value32 * showjim.sys.number.div10000Mul) >> showjim.sys.number.div10000Shift); ToString(value10000, chars + 4); ToString(value32 - value10000 * 10000, chars + 8); if (value100000000 >= 10) { value10000 = (value100000000 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)(chars + 2) = ((value100000000 - value10000 * 10) << 16) | value10000 | 0x300030U; *++chars = '-'; return new string(chars, 0, 11); } *(uint*)(chars += 2) = '-' + ((value100000000 + '0') << 16); return new string(chars, 0, 10); } return ToString_99999999(value32); } private unsafe static string ToString_99999999(uint value) { if (value >= 10000) { char* chars = stackalloc char[10]; uint value10000 = (uint)((value * showjim.sys.number.div10000Mul) >> showjim.sys.number.div10000Shift); if (value10000 >= 100) { uint value10 = (value10000 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; if (value10000 >= 1000) { ToString(value - value10000 * 10000, chars + 6); value = (value10 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)(chars + 4) = ((value10000 - value10 * 10) << 16) | (value10 - value * 10) | 0x300030U; value10 = (value * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)(chars + 2) = ((value - value10 * 10) << 16) | value10 | 0x300030U; *++chars = '-'; return new string(chars, 0, 9); } else { ToString(value - value10000 * 10000, chars + 4); value = (value10 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)(chars + 2) = ((value10000 - value10 * 10) << 16) | (value10 - value * 10) | 0x300030U; *(uint*)chars = '-' + ((value + '0') << 16); return new string(chars, 0, 8); } } else if (value10000 >= 10) { ToString(value - value10000 * 10000, chars + 4); value = (value10000 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)(chars + 2) = ((value10000 - value * 10) << 16) | value | 0x300030U; *++chars = '-'; return new string(chars, 0, 7); } ToString(value - value10000 * 10000, chars + 2); *(uint*)chars = '-' + ((value10000 + '0') << 16); return new string(chars, 0, 6); } else if (value >= 100) { if (value >= 1000) { char* chars = stackalloc char[6]; uint value10 = (value * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; uint value100 = (value10 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)(chars + 4) = ((value - value10 * 10) << 16) | (value10 - value100 * 10) | 0x300030U; value10 = (value100 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)(chars + 2) = ((value100 - value10 * 10) << 16) | value10 | 0x300030U; *++chars = '-'; return new string(chars, 0, 5); } else { char* chars = stackalloc char[4]; uint value10 = (value * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; uint value100 = (value10 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)(chars + 2) = ((value - value10 * 10) << 16) | (value10 - value100 * 10) | 0x300030U; *(uint*)chars = '-' + ((value100 + '0') << 16); return new string(chars, 0, 4); } } else if (value >= 10) { char* chars = stackalloc char[3]; *chars = '-'; uint value10 = (value * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)(chars + 1) = ((value - value10 * 10) << 16) | value10 | 0x300030U; return new string(chars, 0, 3); } else { char* chars = stackalloc char[2]; *(uint*)chars = '-' + ((value + '0') << 16); return new string(chars, 0, 2); } } private unsafe static void ToString(uint value, char* chars) { uint value10 = (value * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; uint value100 = (value10 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)(chars + 2) = ((value - value10 * 10) << 16) | (value10 - value100 * 10) | 0x300030U; value10 = (value100 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)chars = ((value100 - value10 * 10) << 16) | value10 | 0x300030U; } public unsafe static string toString(this ulong value) { if (value >= 10000000000000000L) { char* chars = stackalloc char[20]; ulong value100000000 = value / 100000000; value -= value100000000 * 100000000; uint value10000 = (uint)((value * showjim.sys.number.div10000Mul) >> showjim.sys.number.div10000Shift); ToString(value10000, chars + 12); ToString((uint)value - value10000 * 10000U, chars + 16); value = value100000000 / 100000000; value100000000 -= value * 100000000; value10000 = (uint)((value100000000 * showjim.sys.number.div10000Mul) >> showjim.sys.number.div10000Shift); ToString(value10000, chars + 4); ToString((uint)value100000000 - value10000 * 10000U, chars + 8); uint value32 = (uint)value; if (value32 >= 100) { value10000 = (value32 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; uint value100 = (value10000 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)(chars + 2) = ((value32 - value10000 * 10) << 16) | (value10000 - value100 * 10) | 0x300030U; if (value32 >= 1000) { value10000 = (value100 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)chars = ((value100 - value10000 * 10) << 16) | value10000 | 0x300030U; return new string(chars, 0, 20); } else { *++chars = (char)(value100 + '0'); return new string(chars, 0, 19); } } else if (value32 >= 10) { value10000 = (value32 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)(chars += 2) = ((value32 - value10000 * 10) << 16) | value10000 | 0x300030U; return new string(chars, 0, 18); } *(chars += 3) = (char)(value32 + '0'); return new string(chars, 0, 17); } else if (value >= 100000000) { char* chars = stackalloc char[16]; ulong value100000000 = value / 100000000; value -= value100000000 * 100000000; uint value10000 = (uint)((value * showjim.sys.number.div10000Mul) >> showjim.sys.number.div10000Shift); ToString(value10000, chars + 8); ToString((uint)value - value10000 * 10000U, chars + 12); uint value32 = (uint)value100000000; if (value32 >= 10000) { value10000 = (uint)((value100000000 * showjim.sys.number.div10000Mul) >> showjim.sys.number.div10000Shift); ToString(value32 - value10000 * 10000, chars + 4); if (value10000 >= 100) { value32 = (value10000 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; if (value10000 >= 1000) { uint value100 = (value32 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)(chars + 2) = ((value10000 - value32 * 10) << 16) | (value32 - value100 * 10) | 0x300030U; value32 = (value100 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)chars = ((value100 - value32 * 10) << 16) | value32 | 0x300030U; return new string(chars, 0, 16); } else { chars[3] = (char)((value10000 - value32 * 10) + '0'); uint value100 = (value32 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)(chars += 1) = ((value32 - value100 * 10) << 16) | value100 | 0x300030U; return new string(chars, 0, 15); } } else if (value10000 >= 10) { value32 = (value10000 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)(chars += 2) = ((value10000 - value32 * 10) << 16) | value32 | 0x300030U; return new string(chars, 0, 14); } *(chars += 3) = (char)(value10000 + '0'); return new string(chars, 0, 13); } else if (value32 >= 100) { value10000 = (value32 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; if (value32 >= 1000) { uint value100 = (value10000 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)(chars + 6) = ((value32 - value10000 * 10) << 16) | (value10000 - value100 * 10) | 0x300030U; value10000 = (value100 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)(chars += 4) = ((value100 - value10000 * 10) << 16) | value10000 | 0x300030U; return new string(chars, 0, 12); } else { chars[7] = (char)((value32 - value10000 * 10) + '0'); uint value100 = (value10000 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)(chars += 5) = ((value10000 - value100 * 10) << 16) | value100 | 0x300030U; return new string(chars, 0, 11); } } else if (value32 >= 10) { value10000 = (value32 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)(chars += 6) = ((value32 - value10000 * 10) << 16) | value10000 | 0x300030U; return new string(chars, 0, 10); } *(chars += 7) = (char)(value32 + '0'); return new string(chars, 0, 9); } return ToString99999999((uint)value); } public unsafe static string toString(this long value) { if (value >= 0) return toString((ulong)value); ulong value64 = (ulong)-value; if (value64 >= 10000000000000000L) { char* chars = stackalloc char[22]; ulong value100000000 = value64 / 100000000; value64 -= value100000000 * 100000000; uint value10000 = (uint)((value64 * showjim.sys.number.div10000Mul) >> showjim.sys.number.div10000Shift); ToString(value10000, chars + 14); ToString((uint)value64 - value10000 * 10000U, chars + 18); value64 = value100000000 / 100000000; value100000000 -= value64 * 100000000; value10000 = (uint)((value100000000 * showjim.sys.number.div10000Mul) >> showjim.sys.number.div10000Shift); ToString(value10000, chars + 6); ToString((uint)value100000000 - value10000 * 10000U, chars + 10); uint value32 = (uint)value64; if (value32 >= 100) { value10000 = (value32 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; uint value100 = (value10000 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)(chars + 4) = ((value32 - value10000 * 10) << 16) | (value10000 - value100 * 10) | 0x300030U; if (value32 >= 1000) { value10000 = (value100 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)(chars + 2) = ((value100 - value10000 * 10) << 16) | value10000 | 0x300030U; *++chars = '-'; return new string(chars, 0, 21); } else { *(uint*)(chars += 2) = '-' + ((value100 + '0') << 16); return new string(chars, 0, 20); } } else if (value32 >= 10) { value10000 = (value32 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)(chars + 4) = ((value32 - value10000 * 10) << 16) | value10000 | 0x300030U; *(chars += 3) = '-'; return new string(chars, 0, 19); } *(uint*)(chars += 4) = '-' + ((value32 + '0') << 16); return new string(chars, 0, 18); } else if (value64 >= 100000000) { char* chars = stackalloc char[18]; ulong value100000000 = value64 / 100000000; value64 -= value100000000 * 100000000; uint value10000 = (uint)((value64 * showjim.sys.number.div10000Mul) >> showjim.sys.number.div10000Shift); ToString(value10000, chars + 10); ToString((uint)value64 - value10000 * 10000U, chars + 14); uint value32 = (uint)value100000000; if (value32 >= 10000) { value10000 = (uint)((value100000000 * showjim.sys.number.div10000Mul) >> showjim.sys.number.div10000Shift); ToString(value32 - value10000 * 10000, chars + 6); if (value10000 >= 100) { value32 = (value10000 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; uint value100 = (value32 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)(chars + 4) = ((value10000 - value32 * 10) << 16) | (value32 - value100 * 10) | 0x300030U; if (value10000 >= 1000) { value32 = (value100 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)(chars + 2) = ((value100 - value32 * 10) << 16) | value32 | 0x300030U; *++chars = '-'; return new string(chars, 0, 17); } else { *(uint*)(chars += 2) = '-' + ((value100 + '0') << 16); return new string(chars, 0, 16); } } else if (value10000 >= 10) { value32 = (value10000 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)(chars + 4) = ((value10000 - value32 * 10) << 16) | value32 | 0x300030U; *(chars += 3) = '-'; return new string(chars, 0, 15); } *(uint*)(chars += 4) = '-' + ((value10000 + '0') << 16); return new string(chars, 0, 14); } else if (value32 >= 100) { value10000 = (value32 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; uint value100 = (value10000 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)(chars + 8) = ((value32 - value10000 * 10) << 16) | (value10000 - value100 * 10) | 0x300030U; if (value32 >= 1000) { value10000 = (value100 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)(chars + 6) = ((value100 - value10000 * 10) << 16) | value10000 | 0x300030U; *(chars += 5) = '-'; return new string(chars, 0, 13); } else { *(uint*)(chars += 6) = '-' + ((value100 + '0') << 16); return new string(chars, 0, 12); } } else if (value32 >= 10) { value10000 = (value32 * showjim.sys.number.div10_16Mul) >> showjim.sys.number.div10_16Shift; *(uint*)(chars + 8) = ((value32 - value10000 * 10) << 16) | value10000 | 0x300030U; *(chars += 7) = '-'; return new string(chars, 0, 11); } *(uint*)(chars += 8) = '-' + ((value32 + '0') << 16); return new string(chars, 0, 10); } return ToString_99999999((uint)value64); }这么多啊？代码又长又乱，算了，不整理它了，反正以后只管调用。Release实测，运行时间降到ToString的1/3，还好，这两小时没有白忙活。
TAG:整数 转换 字符串 十进制
