array=(NSArray*)[tempString JSONValue];
[array writeToFile:[documentPath stringByAppendingPathComponent:@"food.plist"] atomically:YES];这里得到array 内容是{
    "food_descripts" = "\U4eba\U5934\U9a6cVSOP\U5927\U793c\U5305";
    "food_father_id" = 261;
    "food_id" = 264;
    "food_ipad_img_url" = "images/178.jpg";
    "food_name" = "\U4eba\U5934\U9a6cVSOP\U5927\U793c\U5305";
    "food_price" = 2380;
}
不能写入plist文件json