iOS Base64编码（文字/图片）

- (NSString *)base64EncodedString {
    NSData *data = [self dataUsingEncoding:NSUTF8StringEncoding];
    return [data base64EncodedStringWithOptions:0];
}

- (NSString *)base64DecodedString {
    NSData *data = [[NSData alloc]initWithBase64EncodedString:self options:0];
    return [[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding];
}

NSString *sourceStr = @"www.baidu.com";
NSLog(@"sourceStr---->%@",sourceStr);

NSString *base64Str = [sourceStr base64EncodedString];
NSLog(@"Base64编码---->%@",base64Str);

NSString *decodeStr = [base64Str base64DecodedString];
NSLog(@"Base64解码---->%@",decodeStr);

/*
 sourceStr---->www.baidu.com
 Base64编码---->d3d3LmJhaWR1LmNvbQ==
 Base64解码---->www.baidu.com
 */

// UIImage图片转成Base64字符串：
UIImage *img = [UIImage imageNamed:@"0.jpg"];
NSData *imgData = UIImageJPEGRepresentation(img, 1.0f);
NSString *encodedImgStr = [imgData base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];

NSLog(@"encodedImgStr---->%@",encodedImgStr);

//Base64字符串转UIImage图片：
NSData *decodedImgData = [[NSData alloc] initWithBase64EncodedString:encodedImgStr options:NSDataBase64DecodingIgnoreUnknownCharacters];
UIImage *decodedImage = [UIImage imageWithData:decodedImgData];

UIImageView *imgV = [[UIImageView alloc] initWithFrame:CGRectMake(0, 100, [UIScreen mainScreen].bounds.size.width, [UIScreen mainScreen].bounds.size.width)];
imgV.contentMode = UIViewContentModeScaleAspectFit;
[imgV setImage:decodedImage];
[self.view addSubview:imgV];

NSLog(@"decodedImage---->%@",decodedImgData);