原生Base64编码/解码（OC与Swift）

Objective-C

NSString *plainString = @"foo";

Encoding

NSData *plainData = [plainString dataUsingEncoding:NSUTF8StringEncoding];

NSString *base64String = [plainData base64EncodedStringWithOptions:0];

NSLog(@"%@", base64String); // Zm9v

Decoding

NSData *decodedData = [[NSData alloc] initWithBase64EncodedString:base64String options:0];

NSString *decodedString = [[NSString alloc] initWithData:decodedData encoding:NSUTF8StringEncoding];

NSLog(@"%@", decodedString); // foo

Swift

let plainString = "foo"

Encoding

let plainData = plainString.dataUsingEncoding(NSUTF8StringEncoding)

let base64String = plainData?.base64EncodedStringWithOptions(.allZeros)

println(base64String!) // Zm9v

Decoding

let decodedData = NSData(base64EncodedString: base64String!, options: .allZeros)

let decodedString = NSString(data: decodedData, encoding: NSUTF8StringEncoding)

println(decodedString) // foo