Swift-使用JSONDecoder解码JSON数据 [英] Swift - decode JSON data with JSONDecoder

问题描述

我正在使用CocktailDB API，并且遇到了一些问题.
我创建了一个请求，以从特定类别中获取鸡尾酒(每个鸡尾酒的名称和图片).然后，我尝试使用Decodable协议解析JSON.但这不起作用，并显示JSON错误.

I'm working with CocktailDB API and having some problems.
I create a request to get cocktails (each cocktail's name and image) from specific category. Then I try to parse JSON with Decodable protocol. But it doesn't work and JSON Error is displayed.

因此，我想从以下请求中获取鸡尾酒类别"https://www.thecocktaildb.com/api/json/v1/1/list.php?c=list"并为每个类别都有一个小节(标题中显示类别名称)，并带有该小节中的鸡尾酒.

Therefore I want to get cocktails categories from the following request "https://www.thecocktaildb.com/api/json/v1/1/list.php?c=list" and have a section for each category (display category name in a header) with the cocktails from this section.

我的饮料型号:

struct Drinks:Decodable {
    var drinks: [Drink]
}

struct Drink:Decodable {
    var strDrink: String
    var strDrinkThumb: String
}

我的类别模型:

struct Categories: Decodable {
    var drinks: [Drink]
}

struct Category: Decodable {
    var strCategory: String
}

我的代码:

    class ViewController: UIViewController {

        var drinks = [Drinks]()
        var categories = [Categories]()
        
        override func viewDidLoad() {
            super.viewDidLoad()
            downloadJSON()
        }
        
        func downloadJSON() {
            let category = "Cocoa" // for example
            let url = URL(string: "https://www.thecocktaildb.com/api/json/v1/1/filter.php?c=\(category)")
            
            URLSession.shared.dataTask(with: url!) { (data, response, error) in
                
                if error == nil {
                    do {
                        self.drinks = try JSONDecoder().decode([Drinks].self, from: data!)
                        print(self.drinks)
                    } catch {
                        print("JSON Error")
                    }
                }
            }.resume()
        }
    }

extension ViewController: UITableViewDataSource, UITableViewDelegate {
    
    func numberOfSections(in tableView: UITableView) -> Int {
        return drinks.count
    }
    
    func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
        return ""
    }
    
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return 1
    }
    
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        return UITableViewCell(style: .default, reuseIdentifier: "cell")
    }
    
    
}

JSON结构:

推荐答案

您需要在此处进行一些其他更改.一种将解码更改为Drinks.self.然后重新加载tableView.并返回该节标题的字符串.这是代码:

You need to make a few additional changes here. One change the decoding to Drinks.self. Then reload the tableView. And return the String for the section header. Here's the code:

解码:

var drinks = [Drink]() // modify the drinks property 

if let data == data {
    do {
        self.drinks = try JSONDecoder().decode(Drinks.self, from: data).drinks
        DispatchQueue.main.async {
            self.tableView.reloadData()
        }
    } catch {
        print(error)
    }
}

和titleForHeaderInSection方法:

And titleForHeaderInSection method:

func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
    return drinks[section].strDrink
}

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