Question

我有这个带有文本和名称的JSON文件：0.json：

public int getItemPosition(Object object) {
    return POSITION_NONE;
}

我从此文件中打印{ "questions" : [{"text1": "1", "text2": "1"}, {"text1": "2", "text2": "2"}, {"text1": "3", "text2": "3"}] }并将其显示在标签

中

我的代码：

text1, text2

当应用开始时，我想要显示第一行struct Root : Decodable { let questions : [Question] } struct Question : Decodable { let text1, text2 : String } override func viewDidLoad() { super.viewDidLoad() let url = Bundle.main.url(forResource: "0", withExtension: "json")! do { let data = try! Data(contentsOf: url) let result = try JSONDecoder().decode(Root.self, from: data) for question in result.questions { label2.text = "\(question.text2)" label1.text = "\(question.text1)" } } catch { print("error: ", error) } }，如果用户点击按钮，我想显示第二行"text1": "1", "text2": "1"，点击按钮后，我想显示第三行"text1": "2", "text2": "2"和等怎么办？

更新代码：

"text1": "3", "text2": "3"

Answer 1

为问题和计数器创建属性

var questions = [Question]()
var counter = 0

viewDidLoad

questions

override func viewDidLoad() {
    super.viewDidLoad()

    let url = Bundle.main.url(forResource: "0", withExtension: "json")!
    let data = try! Data(contentsOf: url)
    let result = try! JSONDecoder().decode(Root.self, from: data)
    self.questions = result.questions
 }

创建IBAction。在正文中获取当前counter值的问题，将文本值分配给标签并递增计数器。如果计数器超过questions中的项目数，则将计数器重置为0（由%运算符方便地执行）。将操作连接到Interface Builder
中的按钮
```
@IBAction func push(_ sender : UIButton)
{
    let question = questions[counter]
    label2.text = question.text2 // no String Interpolation
    label1.text = question.text1
    counter = (counter + 1) % questions.count
}
```

使用按钮显示JSON中的文本

1 个答案: