data和nstring格式互相轉換

 data和nstring格式互相轉換
NSString *strToData = @"http://t3.baidu.com/it/u=3279593072,3159455494&fm=52&gp=0.jpg";
    NSData *aData = [strToData dataUsingEncoding: NSASCIIStringEncoding];
    NSString *dataToStr = [[NSString alloc] initWithData:aData encoding:NSASCIIStringEncoding];
    NSLog(@"%@",dataToStr);