20171101 更新
// base64编码
- (NSString *)base64Encode:(NSString *)string {
// 1.将字符串转换为二进制
NSData *data = [string dataUsingEncoding:NSUTF8StringEncoding];
// 2.二进制数据进行编码
return [data base64EncodedStringWithOptions:0];
}
// base64解码
- (NSString *)base64Decode:(NSString *)string {
// 1.字符串转换为二进制
NSData *data = [[NSData alloc] initWithBase64EncodedString:string options:0];
// 2.解码
return [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
}
声明方法
- (NSString *)base64;
实现方法
- (NSString *)base64 {
NSData *data = [NSData dataWithBytes:[self UTF8String] length:[self lengthOfBytesUsingEncoding:NSUTF8StringEncoding]];
NSUInteger length = [data length];
NSMutableData *mutableData = [NSMutableData dataWithLength:((length + 2) / 3) * 4];
uint8_t *input = (uint8_t *)[data bytes];
uint8_t *output = (uint8_t *)[mutableData mutableBytes];
for (NSUInteger i = 0; i < length; i += 3) {
NSUInteger value = 0;
for (NSUInteger j = i; j < (i + 3); j++) {
value <<= 8;
if (j < length) {
value |= (0xFF & input[j]);
}
}
static uint8_t const kAFBase64EncodingTable[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
NSUInteger idx = (i / 3) * 4;
output[idx + 0] = kAFBase64EncodingTable[(value >> 18) & 0x3F];
output[idx + 1] = kAFBase64EncodingTable[(value >> 12) & 0x3F];
output[idx + 2] = (i + 1) < length ? kAFBase64EncodingTable[(value >> 6) & 0x3F] : '=';
output[idx + 3] = (i + 2) < length ? kAFBase64EncodingTable[(value >> 0) & 0x3F] : '=';
}
return [[NSString alloc] initWithData:mutableData encoding:NSASCIIStringEncoding];
}
