使用 NSData Base64 对字符串进行编码和解码

编码

 //Create a Base64 Encoded NSString Object
 NSData *nsdata = [@"iOS Developer Tips encoded in Base64" dataUsingEncoding:NSUTF8StringEncoding];

 // Get NSString from NSData object in Base64
 NSString *base64Encoded = [nsdata base64EncodedStringWithOptions:0];
 // Print the Base64 encoded string
 NSLog(@"Encoded: %@", base64Encoded);

解码：

// NSData from the Base64 encoded str
NSData *nsdataFromBase64String = [[NSData alloc]initWithBase64EncodedString:base64Encoded options:0];

// Decoded NSString from the NSData
NSString *base64Decoded = [[NSString alloc] initWithData:nsdataFromBase64String encoding:NSUTF8StringEncoding];
NSLog(@"Decoded: %@", base64Decoded);