Question

我想要一个下拉菜单，该菜单根据用户的选择而变化。

例如：

let first_Field = ["-", "new recruits", "police officer", "PSO"] 
let second_field = ["-", "Training", "Courts", "Others"]

第三字段应基于first_Field选择

let third_field = []

因此，我当时认为它可能适用于if条件，但我并不完全知道该怎么做。

例如：

let NR = "new recruits"
let NRtraining = ["Training1", "Training2"]

let first_Field = ["-", NR] 
let second_Field = ["training", "Tester", "School"]
if (first_Field == NR && second_Field == "training") { 
     //user selected NR and training
    //third_Field should show array of NRtraining
}

请帮助？

Answer 1

您应该更改数据结构，例如：

   {
       "new recruits" : {
               "Training" : ["Training1", "Training2"],
               "Courts" : ["Court1","Court2"],
               "Others" : ["abc","def"]
       },
       "police officer" : {
               "Training" : ["Training1", "Training2"],
               "Courts" : ["Court1","Court2"],
               "Others" : ["abc","def"]
       },
      "PSO" : {
               "Training" : ["Training1", "Training2"],
               "Courts" : ["Court1","Court2"],
               "Others" : ["abc","def"]
       }

    }

在选择新兵后，您可以通过“培训，法院，其他人员”键更改第二个下拉菜单；在选择第二个下拉菜单时，您可以使用培训，法院等方面的价值进行第三次下拉菜单

快捷代码：

      let mainDict =  [
            "new recruits" :  [
                "Training" : ["Training1", "Training2"],
                "Courts" : ["Court1","Court2"],
                "Others" : ["abc","def"]
            ],
            "police officer" : [
                "Training" : ["Training1", "Training2"],
                "Courts" : ["Court1","Court2"],
                "Others" : ["abc","def"]
            ],
            "PSO" : [
                "Training" : ["Training1", "Training2"],
                "Courts" : ["Court1","Court2"],
                "Others" : ["abc","def"]
            ]

        ]

        let firstDropArray =  ["-", "new recruits", "police officer", "PSO"]
        var second_field = ["-", "Training", "Courts", "Others"]

        // on select first Dropdown array store value of selected item here i select "new recruits"
        let firstSelect = firstDropArray[1]

        // on select second Dropdown array store value of selected item here i select "Courts"
        let seconSelect = second_field[2]

        // third array value

        let thirdArray = mainDict[firstSelect]![seconSelect]
        print(thirdArray)

创建一个静态下拉菜单

1 个答案: