NSString的编码和解码 UTF8编码

//编码

NSData *nsdata = [@"http://www.baidu.com" 

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);

iOS中对字符串进行UTF-8编码：输出str字符串的UTF-8格式

[str stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

解码：把str字符串以UTF-8规则进行解码

[str stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];