iOS中NSString转换成HEX（十六进制）-NSData转换成int

http://www.2cto.com/kf/201402/281501.html

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NSString *str = @"0xff055008"; //先以16为参数告诉strtoul字符串参数表示16进制数字，然后使用0x%X转为数字类型 unsigned long red = strtoul([str UTF8String],0,16); //strtoul如果传入的字符开头是“0x”,那么第三个参数是0，也是会转为十六进制的,这样写也可以： unsigned long red = strtoul([@"0x6587" UTF8String],0,0); NSLog(@"转换完的数字为：%lx",red);

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// 十六进制转换为普通字符串的。 + (NSString *)stringFromHexString:(NSString *)hexString { //    char *myBuffer = (char *)malloc((int)[hexString length] / 2 + 1); bzero(myBuffer, [hexString length] / 2 + 1); for (int i = 0; i < [hexString length] - 1; i += 2) { unsigned int anInt; NSString * hexCharStr = [hexString substringWithRange:NSMakeRange(i, 2)]; NSScanner * scanner = [[[NSScanner alloc] initWithString:hexCharStr] autorelease]; [scanner scanHexInt:&anInt]; myBuffer[i / 2] = (char)anInt; } NSString *unicodeString = [NSString stringWithCString:myBuffer encoding:4]; NSLog(@"------字符串=======%@",unicodeString); return unicodeString;       }    //普通字符串转换为十六进制的。    + (NSString *)hexStringFromString:(NSString *)string{ NSData *myD = [string dataUsingEncoding:NSUTF8StringEncoding]; Byte *bytes = (Byte *)[myD bytes]; //下面是Byte 转换为16进制。 NSString *hexStr=@""; for(int i=0;i<[myD length];i++)    { NSString *newHexStr = [NSString stringWithFormat:@"%x",bytes[i]&0xff];///16进制数    if([newHexStr length]==1)    hexStr = [NSString stringWithFormat:@"%@0%@",hexStr,newHexStr];    else    hexStr = [NSString stringWithFormat:@"%@%@",hexStr,newHexStr]; } return hexStr; }

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//int 转data int i = 1; NSData *data = [NSData dataWithBytes: &i length: sizeof(i)]; //data 转int int i; [data getBytes: &i length: sizeof(i)];