项目中有较多的多种蓝牙外设的对接 遇到的数据传输比较多 打算从使用框架、模块到传输协议一个系列记录一下
先记录一些数据传输时常用到的转换方式吧 后面再补充
1、整形转换成两个字节
int value = 100;
unsigned char byte1 = (value & 0xff00)>>8; //高8位
unsigned char byte2 = (value & 0xff);//低8位
NSLog(@"byte1= %x byte2= %x ",byte1,byte2);
//byte1 = 0; byte2= 64;
2、两个字节转换成十进制整数
char bytes[]={byte1,byte2};
unsigned char by1 = (bytes[0] & 0xff); //高8位
unsigned char by2 = (bytes[1] & 0xff);//低8位
int temp = (by2|(by1<<8));
NSLog(@"temp = %d",temp);
3、整形转换成三个字节
int value =134456;
unsigned char byte1 = (value & 0xff0000)>>16;//最高8位
unsigned char byte2 = (value & 0xff00)>>8;//中间8位
unsigned char byte3 = (value & 0xff);//低8位
NSLog(@"byte1= %x byte2= %x byte3= %x ",byte1,byte2,byte3);
//byte1= 2 byte2= d byte3= 38
4、三个字节转换成十进制整数
char bytes[]={byte1,byte2,byte3};
unsigned char by1 = (bytes[0] & 0xff); //高8位
unsigned char by2 = (bytes[1] & 0xff);//中8位
unsigned char by3 = (bytes[2] & 0xff);//低8位
int temp = (by3|(by2<<8)|(by1<<16));
NSLog(@"temp = %d",temp);
//temp = 134456
——————有更多的需求以此类推——————
5、16进制字符串转10进制number
// 16进制字符串转10进制
+ (NSNumber *) numberHexString:(NSString *)aHexString
{
if (nil == aHexString){
return nil;
}
NSScanner * scanner = [NSScanner scannerWithString:aHexString];
unsigned long long longlongValue;
[scanner scanHexLongLong:&longlongValue];
//将整数转换为NSNumber,存储到数组中,并返回.
NSNumber * hexNumber = [NSNumber numberWithLongLong:longlongValue];
return hexNumber;
}
6、16进制字符串转NSData
//将16进制的字符串转换成NSData
+ (NSMutableData *)convertHexStrToData:(NSString *)str {
if (!str || [str length] == 0) {
return nil;
}
NSMutableData *hexData = [[NSMutableData alloc] initWithCapacity:8];
NSRange range;
if ([str length] %2 == 0) {
range = NSMakeRange(0,2);
} else {
range = NSMakeRange(0,1);
}
for (NSInteger i = range.location; i < [str length]; i += 2) {
unsigned int anInt;
NSString *hexCharStr = [str substringWithRange:range];
NSScanner *scanner = [[NSScanner alloc] initWithString:hexCharStr];
[scanner scanHexInt:&anInt];
NSData *entity = [[NSData alloc] initWithBytes:&anInt length:1];
[hexData appendData:entity];
range.location += range.length;
range.length = 2;
}
return hexData;
}
7、简单的10进制转16进制字符串
//int 转16进制
+ (NSString *)hexFromInt:(NSInteger)val {
return [NSString stringWithFormat:@"%X", val];
}
8、NSData转器16进制
+ (NSString *)hexStringFromData:(NSData *)data
{
NSAssert(data.length > 0, @"data.length <= 0");
NSMutableString *hexString = [[NSMutableString alloc] init];
const Byte *bytes = data.bytes;
for (NSUInteger i=0; i<data.length; i++) {
Byte value = bytes[i];
Byte high = (value & 0xf0) >> 4;
Byte low = value & 0xf;
[hexString appendFormat:@"%x%x", high, low];
}//for
return hexString;
}
9、NSString 转NSData
NSData *data = [aString dataUsingEncoding:NSUTF8StringEncoding];// 通过utf-8转为data
10、uint8、NSData(占两位)互转
//uint8转NSData
+ (NSData *)byteFromUInt8:(uint8_t)val
{
NSMutableData *valData = [[NSMutableData alloc] init];
unsigned char valChar[1];
valChar[0] = 0xff & val;
[valData appendBytes:valChar length:1];
return [self dataWithReverse:valData];
}
//NSData转uint8_t
+ (uint8_t)uint8FromBytes:(NSData *)fData
{
NSAssert(fData.length == 1, @"uint8FromBytes: (data length != 1)");
NSData *data = fData;
uint8_t val = 0;
[data getBytes:&val length:1];
return val;
}
11、uint16 、NSData（占四位）互转
//uint16 转NSData
+ (NSData *)bytesFromUInt16:(uint16_t)val
{
NSMutableData *valData = [[NSMutableData alloc] init];
unsigned char valChar[2];
valChar[0] = 0xff & val;
valChar[1] = (0xff00 & val) >> 8;
[valData appendBytes:valChar length:2];
return [self dataWithReverse:valData];
}
//NSData转uint16
+ (uint16_t)uint16FromBytes:(NSData *)fData
{
NSAssert(fData.length == 2, @"uint16FromBytes: (data length != 2)");
NSData *data = [self dataWithReverse:fData];;
uint16_t val0 = 0;
uint16_t val1 = 0;
[data getBytes:&val0 range:NSMakeRange(0, 1)];
[data getBytes:&val1 range:NSMakeRange(1, 1)];
uint16_t dstVal = (val0 & 0xff) + ((val1 << 8) & 0xff00);
return dstVal;
}
12、uint32 与NSData互转
//uint32 转NSData（占八位）
+ (NSData *)bytesFromUInt32:(uint32_t)val
{
NSMutableData *valData = [[NSMutableData alloc] init];
unsigned char valChar[4];
valChar[0] = 0xff & val;
valChar[1] = (0xff00 & val) >> 8;
valChar[2] = (0xff0000 & val) >> 16;
valChar[3] = (0xff000000 & val) >> 24;
[valData appendBytes:valChar length:4];
return [self dataWithReverse:valData];
}
//NSData转Uint32
+ (uint32_t)uint32FromBytes:(NSData *)fData
{
NSAssert(fData.length == 4, @"uint32FromBytes: (data length != 4)");
NSData *data = [self dataWithReverse:fData];
uint32_t val0 = 0;
uint32_t val1 = 0;
uint32_t val2 = 0;
uint32_t val3 = 0;
[data getBytes:&val0 range:NSMakeRange(0, 1)];
[data getBytes:&val1 range:NSMakeRange(1, 1)];
[data getBytes:&val2 range:NSMakeRange(2, 1)];
[data getBytes:&val3 range:NSMakeRange(3, 1)];
uint32_t dstVal = (val0 & 0xff) + ((val1 << 8) & 0xff00) + ((val2 << 16) & 0xff0000) + ((val3 << 24) & 0xff000000);
return dstVal;
}
13、data转byte
uint8_t byteArray[[data length]];
[data getBytes:&byteArray length:[data length]];
for (int i = 0; i < [data length] ; i++ ) {
Byte byte = byteArray[i];
NSLog(@"--byte%x",byte);
}
14、NSData转int (用CFSwapInt32BigToHost)
NSData *data4 = [completeData subdataWithRange:NSMakeRange(0, 4)];
int value = CFSwapInt32BigToHost(*(int*)([data4 bytes]));
//NSData转成NSinteger
- (NSInteger)intFormData:(NSData *)data
{
const uint8_t *reportData = [data bytes];
uint16_t bpm = 0;
if ((reportData[0] & 0x01) == 0){
/* uint8 bpm */
bpm = reportData[1];
}
else{
/* uint16 bpm */
bpm = CFSwapInt16LittleToHost(*(uint16_t *)(&reportData[1]));
}
return bpm;
}
15、可能会用到的反转字节序列代码
+ (NSData *)dataWithReverse:(NSData *)srcData
{
NSUInteger byteCount = srcData.length;
NSMutableData *dstData = [[NSMutableData alloc] initWithData:srcData];
NSUInteger halfLength = byteCount / 2;
for (NSUInteger i=0; i<halfLength; i++) {
NSRange begin = NSMakeRange(i, 1);
NSRange end = NSMakeRange(byteCount - i - 1, 1);
NSData *beginData = [srcData subdataWithRange:begin];
NSData *endData = [srcData subdataWithRange:end];
[dstData replaceBytesInRange:begin withBytes:endData.bytes];
[dstData replaceBytesInRange:end withBytes:beginData.bytes];
}
return dstData;
}
16、大小端转换
#define Tranverse16(X) ((((UInt16)(X) & 0xff00) >> 8) |(((UInt16)(X) & 0x00ff) << 8))
#define Tranverse32(X) ((((UInt32)(X) & 0xff000000) >> 24) | (((UInt32)(X) & 0x00ff0000) >> 8) | (((UInt32)(X) & 0x0000ff00) << 8) | (((UInt32)(X) & 0x000000ff) << 24))
#define Tranverse64(X) ((((UInt64)(X) & 0xff00000000000000) >> 56) | (((UInt64)(X) & 0x00ff000000000000) >> 40) | (((UInt64)(X) & 0x0000ff0000000000) >> 24) | (((UInt64)(X) & 0x000000ff00000000) >> 8) | (((UInt64)(X) & 0x00000000ff000000) << 8) | (((UInt64)(X) & 0x0000000000ff0000) << 24) | (((UInt64)(X) & 0x000000000000ff00) << 40) | (((UInt64)(X) & 0x00000000000000ff) << 56))
