swift - 使用 Swift 2 进行不区分大小写(不区分大小写)搜索

Question

我在 Parse 中有一个名为“Friends”的类(class)。我添加了一个搜索栏(没有搜索显示 Controller )。我希望能够通过搜索“john doe”来搜索“John Doe”。我能够做到这一点的唯一方法是在 Parse 中将 "first_name" 和 "last_name" 下的“ friend ”全部小写。然后我将 searchBar.text 转换为 lowerCaseString 并且它可以工作。我似乎无法将 "first_name" 或 "last_name" 转换为 lowerCaseString。
有任何想法吗？谢谢!

<小时/>

class ViewController: UIViewController, UITableViewDataSource,UITableViewDelegate, UISearchBarDelegate {
@IBOutlet weak var myTableView: UITableView!
@IBOutlet weak var mySearchBar: UISearchBar!


var searchResults = [String]()

override func viewDidLoad() {
    super.viewDidLoad()



}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()

}

func searchBarSearchButtonClicked(searchBar: UISearchBar)
{
    searchBar.resignFirstResponder()
    print("Search word = \(searchBar.text!)")


    let firstNameQuery = PFQuery(className:"Friends")
    firstNameQuery.whereKey("first_name".lowercaseString, matchesRegex: searchBar.text!.lowercaseString)



    let lastNameQuery = PFQuery(className:"Friends")
    lastNameQuery.whereKey("last_name".lowercaseString, matchesRegex: searchBar.text!.lowercaseString)

    // lastNameQuery.whereKey("last_name", matchesRegex: "(?i)\(searchBar.text)") <- Instead of firstNameQuery.whereKey("first_name", containsString: searchBar.text)






    let query = PFQuery.orQueryWithSubqueries([firstNameQuery, lastNameQuery])

    query.findObjectsInBackgroundWithBlock {
        (results: [AnyObject]?, error: NSError?) -> Void in

        if error != nil {
            let myAlert = UIAlertController(title:"Alert", message:error?.localizedDescription, preferredStyle:UIAlertControllerStyle.Alert)

            let okAction = UIAlertAction(title: "Ok", style: UIAlertActionStyle.Default, handler: nil)

            myAlert.addAction(okAction)

            self.presentViewController(myAlert, animated: true, completion: nil)

            return
        }

        if let objects = results as? [PFObject] {

            self.searchResults.removeAll(keepCapacity: false)

            for object in objects {
                let firstName = object.objectForKey("first_name") as! String
                let lastName = object.objectForKey("last_name") as! String
                let fullName = firstName + " " + lastName

                self.searchResults.append(fullName)
            }

            dispatch_async(dispatch_get_main_queue()) {
                self.myTableView.reloadData()
                self.mySearchBar.resignFirstResponder()

            }



        }




    }

}




func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int
{
    return searchResults.count
}

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell
{
    let myCell = tableView.dequeueReusableCellWithIdentifier("myCell", forIndexPath: indexPath) 

    myCell.textLabel?.text = searchResults[indexPath.row]

    return myCell
}

func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath)
{
    mySearchBar.resignFirstResponder()
}

func searchBarCancelButtonClicked(searchBar: UISearchBar)
{
    mySearchBar.resignFirstResponder()
    mySearchBar.text = ""
}

@IBAction func refreshButtonTapped(sender: AnyObject) {
    mySearchBar.resignFirstResponder()
    mySearchBar.text = ""
    self.searchResults.removeAll(keepCapacity: false)
    self.myTableView.reloadData()
}


}

Answer 1

使用 NSStringCompareOption 进行不区分大小写的搜索。如果您使用此函数，那么结果将显示包含该子字符串的所有字符串。

let range = temp.rangeOfString(searchText, options: NSStringCompareOptions.CaseInsensitiveSearch)
if range.location != NSNotFound {
    print("match")
}

如果您只想得到以特定搜索字符串开头的结果。只需检查范围是否从字符串的第一个字符开始。