ios中查询文件大小。

    NSArray * paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);

    NSString * documentsDirectory = [paths objectAtIndex:0];

    NSString * filename = [documentsDirectory stringByAppendingPathComponent:@"1.png"];

    NSLog(@"filename  = %@",filename);

     NSDictionary *fileAttributes = [[NSFileManager defaultManager] fileAttributesAtPath:filename traverseLink:YES];

    unsigned long long length = [fileAttributes fileSize];

    float ff = length/1024.0/1024.0;

    NSLog(@"length== %.2f",ff);