如何搜索结构 (Swift) [英] How to Search Struct (Swift)

问题描述

我正在更改我的 2 个数组...

I am changing my 2 arrays...

var title = ["Title 1", "Title 2", "Title 3"]
var artist = ["Artist 1", "Artist 2", "Artist 3"]

...到一个结构

struct Song {
    var title: String
    var artist: String
}

var songs: [Song] = [
    Song(title: "Title 1", artist "Artist 1"),
    Song(title: "Title 2", artist "Artist 2"),
    Song(title: "Title 3", artist "Artist 3"),
]

我设置了我的 UITableView 以便单元格的标题等于 songs[indexPath.row].title，单元格的副标题等于 songs[indexPath.row].artist.

I set up my UITableView so that the title of the cell equals songs[indexPath.row].title, and the subtitle of the cell equals songs[indexPath.row].artist.

但是，我希望能够使用 UISearchBar 搜索 UITableView.每当我只有变量而不是结构时，它就可以正常工作.但是，现在我发现了一个错误

But, I want to be able to search the UITableView with a UISearchBar. Whenever I just had the variables and not the struct, it worked fine. But, now I am finding an error on

var filteredTitles:[String] = []
var searchActive : Bool = false

func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {

    filteredTitles = title.filter //the error ({ (text) -> Bool in
        let tmp: NSString = text as NSString
        let range = tmp.range(of: searchText, options: NSString.CompareOptions.caseInsensitive)
        return range.location != NSNotFound
    })
        if(filteredTitles.count == 0){
        searchActive = false;
    } else {
        searchActive = true;
    }
    self.myTableView.reloadData()
}

如您所见，在 filteredTitles = title.filter 行上，它调用了我的旧变量 title.我应该用什么替换这一行，以便它搜索结构的标题?

As you can see, on the line filteredTitles = title.filter it calls my old variable, title. What should I replace this line with so that it searches the struct's title?

感谢您的帮助！

推荐答案

您需要将您的 filteredTitles 更改为 Song 的数组(并将其重命名为 过滤歌曲.

You need to change your filteredTitles to be an array of Song (and rename it to filteredSongs.

然后更新对 filter 的调用，以便将 text 替换为 song 并访问 title 属性歌曲.

Then update the call to filter such that text is replaced with song and you access the title property of song.

并且不需要将标题转换为 NSString.

And there is no need to cast the title to NSString.

这是您需要更改的代码:

Here's your code with the needed changes:

var filteredSongs = [Song]()
var searchActive = false

func searchBar(searchText: String) {
    filteredSongs = songs.filter { (song) -> Bool in
        return song.title.range(of: searchText, options: [ .caseInsensitive ]) != nil
    }

    searchActive = !filteredSongs.isEmpty

    self.myTableView.reloadData()
}

这里假设 songs 是你的歌曲数组.

This assumes songs is your array of songs.

请注意，还有很多其他清理工作.

Note there is a lot of other cleanup too.

你可能需要更新你的表视图数据源方法来处理 filteredSongs 是一个 Song 数组而不是一个 String 数组>.

And you probably need to update your table view data source methods to deal with filteredSongs being an array of Song instead of an array of String.

这篇关于如何搜索结构 (Swift)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！