NSSearchPathForDirectoriesInDomains用法

这个主要就是返回一个绝对路径用来存放我们需要储存的文件。

- (NSString *)dataFilePath {
   NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES);
   NSString *documentsDirectory = [paths objectAtIndex:0];
   return [documentsDirectory stringByAppendingPathComponent:@"shoppingCar.plist"];
}
NSFileManager* fm=[NSFileManager defaultManager];
if(![fm fileExistsAtPath:[self dataFilePath]]){
   //下面是对该文件进行制定路径的保存
   [fm createDirectoryAtPath:[self dataFilePath] withIntermediateDirectories:YES attributes:nil error:nil];
   //取得一个目录下得所有文件名
   NSArray *files = [fm subpathsAtPath: [self dataFilePath] ];
   //读取某个文件
   NSData *data = [fm contentsAtPath:[self dataFilePath]];
   //或者
   NSData *data = [NSData dataWithContentOfPath:[self dataFilePath]];
}