iOS开发之Base64编码与解码

原理:

1>ASCII码是8个二进制位一编码
2>Base64编码是6个二进制位一编码,所以转换成字符串后会比ASCII内容要多

调用Base64编码与解码

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
    NSString *man = [self encode:@"Man"];
    NSLog(@"%@",man);
    
    NSString *orginMan = [self dencode:man];
    NSLog(@"%@",orginMan);
}

//64编码

- (NSString *)encode:(NSString *)string
{
    //先将string转换成data
    NSData *data = [string dataUsingEncoding:NSUTF8StringEncoding];
    
    NSData *base64Data = [data base64EncodedDataWithOptions:0];
    
    NSString *baseString = [[NSString alloc]initWithData:base64Data encoding:NSUTF8StringEncoding];
    
    return baseString;
}

//64解码

- (NSString *)dencode:(NSString *)base64String
{
    //NSData *base64data = [string dataUsingEncoding:NSUTF8StringEncoding];
    
    NSData *data = [[NSData alloc]initWithBase64EncodedString:base64String options:NSDataBase64DecodingIgnoreUnknownCharacters];
    
    NSString *string = [[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding];
    
    return string;
}