过滤数组并在表视图中显示? [英] Filtering Array and displaying in Table View?

问题描述

我想在练习字典中搜索名称键，然后在表格视图中显示过滤结果.我正在使用这个功能

I want to search an dictionary of exercises for the name key and then show the filtered result in the table view. I am using this function

func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {
    let filtered = exercises.filter { $0["name"] == searchText }
    print(filtered)

    if(filtered.count == 0){
        searchActive = false;
    } else {
        searchActive = true;
    }
    self.exercisesTableView.reloadData()
}

变量:

var exercises = [Exercise]()
var filtered: [NSMutableArray] = []
var searchActive: Bool = false

在搜索功能中出现错误

Type'Exercise' 没有下标成员

Type'Exercise' has no subscript members

然后我的问题是结果是 NSMutableArray，所以我无法将结果名称设置为要显示的单元格文本

and then i have the issue that the result is an NSMutableArray and so I cant set the result names as cell text to display

无法在强制转换中将NSMutableArray"类型的值转换为String"类型

Cannot convert value of type 'NSMutableArray' to type 'String' in coercion

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath)
    if (searchActive){
        cell.textLabel?.text = filtered[indexPath.row] as String
    } else {
        let exercise = exercises[indexPath.row]

        cell.textLabel!.text = exercise.name
    }
    return cell
}

这是我的练习词典以供参考:

Here is my Exercise dictionary for reference:

final public class Exercise {
    var id: Int
    var descrip: String
    var name: String
    var muscles: [Int]
    var equipment: [Int]

    public init?(dictionary: [String: Any]) {

        guard
            let id = dictionary["id"] as? Int,
            let descrip = dictionary["description"] as? String,
            let name = dictionary["name"] as? String,
            let muscles = dictionary["muscles"] as? [Int],
            let equipment = dictionary["equipment"] as? [Int]

            else { return nil }

        self.id = id
        self.descrip = descrip
        self.name = name
        self.muscles = muscles
        self.equipment = equipment

    }

我可以通过使 var 过滤来修复第二个错误:[String] = [] 因此它可以用作单元格标题，但这并不能解决第一个错误，我不确定解决它的方法是否正确?

I can fix the second error by making var filtered: [String] = [] so it can be used as a cell title, but that doesnt resolve the first error and im not sure is the right way to go about it?

推荐答案

你的 filtered 也是 [Exercise] 类型，你需要像过滤它一样.

Your filtered also type of [Exercise] and you need to filter it like.

var filtered = [Exercise]() 

self.filtered = exercises.filter { $0.name == searchText }

这里的$0 是Exercise 对象的类型，因此您需要使用$0.name 访问其属性名称.

Here $0 is type of Exercise object, so you need to access its property name using $0.name.

如果您希望 filtered 作为 [String] 的类型，只有名称，那么您可能需要同时使用 map 和 filter 像这样.

If you want filtered as type of [String] with only name then you can need to use both map and filter like this.

self.filtered = exercises.filter { $0.name == searchText }.map { $0.name }

或

self.filtered = exercises.map { $0.name }.filter { $0 == searchText }

OR 直接使用 filterMap 作为@dfri 建议.

OR directly using filterMap as @dfri suggested.

self.filtered = exercises.flatMap{ $0.name == searchText ? $0.name : nil }

这篇关于过滤数组并在表视图中显示?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！