Objective-C 将十六进制字符串解析为整数

我想知道如何在 Objective-C 中解析表示数字的十六进制字符串。我愿意同时使用目标或基于 C 的方法，两者都可以。

例如:

#01FFFFAB

应该解析成整数: 33554347

如果你能帮忙，我会很感激的！

58134 次浏览
小开

you can use NSScanner for this

unsigned int outVal;
NSScanner* scanner = [NSScanner scannerWithString:@"0x01FFFFAB"];
[scanner scanHexInt:&outVal];

outVal will contain the int you're looking for. The 0x is optional.

小开

strtol() is your friend.

It converts a string to a long, and you can pass the base of the number in. Strip that # sign off first though, or pass to strtol a pointer to the first numerical character.

小开
最佳答案

Joshua Weinberg's answer is mostly correct, however the 0x prefix is optional when scanning hexadecimal integers. If you have a string in the format #01FFFFAB, you can still use NSScanner, but you can skip the first character.

unsigned result = 0;
NSScanner *scanner = [NSScanner scannerWithString:@"#01FFFFAB"];


[scanner setScanLocation:1]; // bypass '#' character
[scanner scanHexInt:&result];
小开

You can use the below line for conversion. Its just one line code:

NSString *hexString = @"01FFFFAB";
length = (UInt64)strtoull([hexString UTF8String], NULL, 16);
NSLog(@"The required Length is %d", length);

Happy Coding!!!

小开

According to apple:

An NSScanner object interprets and converts the characters of an NSString object into number and string values.

so, if u have NSData obj u can do next 

NSString *dataDescription = data.description;
NSString *dataAsString = [dataDescription substringWithRange:NSMakeRange(1, [dataDescription length]-2)];
unsigned intData = 0;
NSScanner *scanner = [NSScanner scannerWithString:dataAsString];
[scanner scanHexInt:&intData];
小开

For Swift 3:

var hex = "#01FFFFAB"
hex.remove(at: hex.startIndex)
var rgbValue:UInt32 = 0
Scanner(string: hex).scanHexInt32(&rgbValue)
// rgbValue == 33554347
小开

Swift 4 standard library introduced new initializer for parsing all integer types. It takes string to parse with radix (i.e. base) and returns optional integer:

let number = Int("01FFFFAB", radix: 16)!

提交答案