您好我从JSON重新获得了值并存储在NSMutableArray中。我试过这个像辛格尔顿一样。我已经使用了空的swift文件。数据已成功检索并存储在已在mainViewController中声明的NSMutableArray中。然后,如果我在mainViewController中使用该NSMutableArray值,它将显示空数组。
我的编码如下。请指导我。
清空Swift文件
public class json_file{
var prod_Obj = product_mainVC()
class var shared: json_file
{
struct Static
{
static let instance: json_file = json_file()
}
return Static.instance
}
func dataFromJSON()
{
let url = NSURL(string: "http://........--...4900a20659")!
var data : NSData = NSData(contentsOfURL: url, options: NSDataReadingOptions.DataReadingMapped, error: nil)!
var dict: NSDictionary! = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.MutableContainers, error: nil) as NSDictionary
let dataArray = dict["data"] as [[String:AnyObject]] // The array of dictionaries
for object in dataArray {
let category_name = object["category_name"] as String
prod_Obj.ct_name_arr.addObject(category_name)
let category_child = object["category_child"] as [[String:AnyObject]]
for child in category_child {
let sub_category_name = child["sub_category_name"] as String
prod_Obj.sub_ct_name_arr.addObject(sub_category_name)
}
}
println(prod_Obj.ct_name_arr) //Here value is Getting
println(prod_Obj.sub_ct_name_arr) //Here value is Getting
}
}
viewDidLoad中
{
json_file.shared.dataFromJSON()
println(ct_name_arr) //Prints Empty Array [Intially Declared as NSMutableArray]
println(sub_ct_name_arr) //Prints Empty Array [Intially Declared as NSMutableArray]
}
答案 0 :(得分:0)
我试图了解问题,但我看不到product_mainVC
。因为我重新修改了你的课程。
class JsonFile
{
private(set) var categoryNames:[String];
private(set) var subCategoryNames:[String];
class let shared:JsonFile = JsonFile();
private init()
{
self.categoryNames = [];
self.subCategoryNames = [];
}
func dataFromJson()
{
let url = NSURL(string: "http://........--...4900a20659")!
if let data : NSData = NSData(contentsOfURL: url, options: NSDataReadingOptions.DataReadingMapped, error: nil)
{
if let dict: NSDictionary! = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.MutableContainers, error: nil) as? NSDictionary
{
if let dataArray = dict["data"] as? [[String:AnyObject]] // The array of dictionaries
{
for object in dataArray {
let category_id = object["category_id"] as Int
let category_name = object["category_name"] as String
categoryNames.append(category_name);
let category_child = object["category_child"] as [[String:AnyObject]]
for child in category_child {
let sub_category_id = child["sub_category_id"] as Int
let sub_category_name = child["sub_category_name"] as String
subCategoryNames.append(sub_category_name);
}
}
}
}
}
println(categoryNames);
println(subCategoryNames);
}
}
修改你的Singleton
方式到一个安全且更简单的模式,在类中创建数组categoryNames
和subCategoryNames
内部,因为这样可以更好地操作和保护你的获取数据以防止可能的崩溃。
JsonFile.shared.dataFromJson();
println("count categoryNames");
println(JsonFile.shared.categoryNames.count);
println("count subCategoryNames");
println(JsonFile.shared.subCategoryNames.count);
此代码是同步的,因为如果您的数据或请求速度很慢,应用程序中的主线程将冻结等待返回,这对您的用户不利。想想是否有必要同步。
永远不会使用 let category_id = object["category_id"] as Int
。为什么要在代码中使用它?