Objective-C 中Socket常用转换机制（NSData
2021-12-02 本文已影响0人
hanyongwei
- int类型转16进制hexstring
//int 转16进制
- (NSString *)hexFromInt:(NSInteger)val {
return [NSString stringWithFormat:@"%X", val];
}
2.16进制转换为NSData
+ (NSData *)dataFromHexString:(NSString *)hexString
{
NSAssert((hexString.length > 0) && (hexString.length % 2 == 0), @"hexString.length mod 2 != 0");
NSMutableData *data = [[NSMutableData alloc] init];
for (NSUInteger i=0; i<hexString.length; i+=2) {
NSRange tempRange = NSMakeRange(i, 2);
NSString *tempStr = [hexString substringWithRange:tempRange];
NSScanner *scanner = [NSScanner scannerWithString:tempStr];
unsigned int tempIntValue;
[scanner scanHexInt:&tempIntValue];
[data appendBytes:&tempIntValue length:1];
}
return data;
}
3.NSData转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;
}
4.NSString转int类型
int a = [aStrinng intValue];
5.uint8转NSData(占两位)
+ (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];
}
6.uint16 转NSData（占四位）
+ (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];
}
7.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];
}
8.NSString 转NSData
NSData *data = [aString dataUsingEncoding:NSUTF8StringEncoding];// 通过utf-8转为data
9.NSData转Uint8
+ (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;
}
10.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;
}
11.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;
}
12.NSData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);
}
13.NSData的拼接
[data1 appendData:data2];
14.NSData转int (用CFSwapInt32BigToHost)
NSData *data4 = [completeData subdataWithRange:NSMakeRange(0, 4)];
int value = CFSwapInt32BigToHost(*(int*)([data4 bytes]));
以上可能会用到的反转字节序列代码
+ (NSData *)dataWithReverse:(NSData *)srcData
{
// NSMutableData *dstData = [[NSMutableData alloc] init];
// for (NSUInteger i=0; i<srcData.length; i++) {
// [dstData appendData:[srcData subdataWithRange:NSMakeRange(srcData.length-1-i, 1)]];
// }//for
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];
}//for
return dstData;
}
以上内容来自原址
15.NSData转int8_t
+(int8_t) int8FromBytes:(NSData *)data
{
NSUInteger len = [data length];
Byte *by=(Byte *)malloc(len);
memcpy(by, [data bytes], len);
int8_t ret=by[0] & 0xff;
free(by);
return ret;
}
16.NSData转int16_t
//bigEndian 传NO就行
+(int16_t) int16FromBytes:(NSData *)data bigEndian:(BOOL)bigEndian
{
NSUInteger len = [data length];
Byte *by=(Byte *)malloc(len);
memcpy(by, [data bytes], len);
int16_t ret=((by[1] & 0xFF) << 8) + (by[0] & 0xff);
if (bigEndian) {
ret=((by[0] & 0xFF) << 8) + (by[1] & 0xff);
}
free(by);
return ret;
}
17.NSData转int32_t
//bigEndian 传NO就行
+(int32_t) int32FromBytes:(NSData *)data bigEndian:(BOOL)bigEndian
{
NSUInteger len = [data length];
Byte *by=(Byte *)malloc(len);
memcpy(by, [data bytes], len);
int32_t ret=(by[3] << 24) + ((by[2] & 0xFF) << 16) + ((by[1] & 0xFF) << 8) + (by[0] & 0xFF);
if (bigEndian) {
ret = ((by[0] & 0xFF) << 24) + ((by[1] & 0xFF) << 16) + ((by[2] & 0xFF) << 8) + (by[3] & 0xff);
}
free(by);
return ret;
}
18.NSData转float
+(float)float32FromBytes:(NSData *)data bigEndian:(BOOL)bigEndian
{
NSUInteger len = [data length];
Byte *by=(Byte *)malloc(len);
memcpy(by, [data bytes], len);
float valf=0.0;
char *temp=(char *)(&valf);
if(bigEndian)
{
temp[3]=by[0];
temp[2]=by[1];
temp[1]=by[2];
temp[0]=by[3];
}else{
temp[3]=by[3];
temp[2]=by[2];
temp[1]=by[1];
temp[0]=by[0];
}
free(by);
return valf;
}
19.int8_t转NSData(占两位)
+(NSData *) byteFromInt8:(int)val
{
char myByteArray[] = {0};
myByteArray[0]=val & 0xff;
NSData *ret=[NSData dataWithBytes:myByteArray length:1];
return ret;
}
20.int16_t 转NSData（占四位）
//bigEndian 传no
+(NSData *) bytesFromInt16:(int)val bigEndian:(BOOL)bigEndian
{
char myByteArray[] = {0,0};
myByteArray[0]=val & 0xff;
myByteArray[1]=(val>>8) & 0xff;
if(bigEndian)
{
myByteArray[1]=val & 0xff;
myByteArray[0]=(val>>8) & 0xff;
}else{
myByteArray[0]=val & 0xff;
myByteArray[1]=(val>>8) & 0xff;
}
NSData *ret=[NSData dataWithBytes:myByteArray length:2];
return ret;
}
21.int32_t 转NSData（占八位）
//bigEndian 传no
+(NSData *) bytesFromInt32:(int)val bigEndian:(BOOL)bigEndian
{
char myByteArray[] = {0,0,0,0};
if(bigEndian)
{
myByteArray[3]=val & 0xff;
myByteArray[2]=(val>>8) & 0xff;
myByteArray[1]=(val>>16) & 0xff;
myByteArray[0]=(val>>24) & 0xff;
}else{
myByteArray[0]=val & 0xff;
myByteArray[1]=(val>>8) & 0xff;
myByteArray[2]=(val>>16) & 0xff;
myByteArray[3]=(val>>24) & 0xff;
}
NSData *ret=[NSData dataWithBytes:myByteArray length:4];
return ret;
}
22.float转NSData
//bigEndian 传no
+(NSData *) bytesFromfloat32:(float)val bigEndian:(BOOL)bigEndian
{
float valf=val;
char myByteArray[] = {0,0,0,0};
char *temp=(char *)(&valf);
if(bigEndian)
{
myByteArray[3]=temp[0];
myByteArray[2]=temp[1];
myByteArray[1]=temp[2];
myByteArray[0]=temp[3];
}else{
myByteArray[3]=temp[3];
myByteArray[2]=temp[2];
myByteArray[1]=temp[1];
myByteArray[0]=temp[0];
}
NSData *ret=[NSData dataWithBytes:myByteArray length:4];
return ret;
}
