点击搜索栏时出现此错误：
由于未捕获的异常终止应用程序＆＃39; NSInvalidArgumentException＆＃39;，原因：＆＃39;无法使用收集Assignment_4.SearchResult进入/包含运算符（studentID：＆＃34; 1060＆＃34; ，lastName：＆＃34; Squarepants＆＃34;，firstName：＆＃34; Spongebob＆＃34;，major：＆＃34; Krusty Krab Chef＆＃34;，year：＆＃34; Junior＆＃34;，gpa：＆ ＃34; 4.0＆＃34;）（不是集合）＆＃39;
在此行中获取错误。
let array = (results as NSArray).filtered(using: searchPredicate)
这是整个代码。我无法弄清楚出了什么问题。谢谢！
var results = [SearchResult]()
var indexN = 0
var addStudent = false
var searchController: UISearchController!
var filteredTableData = [String]()
var resultSearchController = UISearchController()
@IBAction func AddStudentButton(_ sender: Any) {
addStudent=true
performSegue(withIdentifier: "detailSegue", sender: self)
}
@IBAction func refreshButton(_ sender: Any) {
refreshTable()
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
listTableView.delegate = self
listTableView.dataSource = self
listTableView.reloadData()
jsonParser()
self.resultSearchController = ({
let controller = UISearchController(searchResultsController: nil)
controller.searchResultsUpdater = self
controller.dimsBackgroundDuringPresentation = true
controller.searchBar.sizeToFit()
self.listTableView.tableHeaderView = controller.searchBar
return controller
})()
self.listTableView.reloadData()
}
/*
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 1
}
*/
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
if (self.resultSearchController.isActive) {
return self.filteredTableData.count
}
else {
return self.results.count
}
// return self.results.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell:UITableViewCell = UITableViewCell(style:UITableViewCellStyle.subtitle, reuseIdentifier: "cell")
//cell.textLabel!.text = self.results[indexPath.row].firstName + " " + results[indexPath.row].lastName
//return cell
// let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath)
if (self.resultSearchController.isActive) {
cell.textLabel?.text = filteredTableData[indexPath.row]
return cell
}
else {
cell.textLabel?.text = self.results[indexPath.row].firstName + " " + results[indexPath.row].lastName
return cell
}
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
indexN = indexPath.row
addStudent=false
performSegue(withIdentifier: "detailSegue", sender: self)
}
func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
return true
}
func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCellEditingStyle, forRowAt indexPath: IndexPath) {
if (editingStyle == UITableViewCellEditingStyle.delete) {
// handle delete (by removing the data from your array and updating the tableview)
Delete(studentID: self.results[indexN].studentID)
refreshTable()
}
}
func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func jsonParser() {
let urlPath = "http://csmadison.dhcp.bsu.edu/~vjtanksale/cs320/selectstudents.php"
guard let endpoint = URL(string: urlPath) else {
print("Error creating endpoint")
return
}
let request = URLRequest(url: endpoint)
URLSession.shared.dataTask(with: request) { (data, response, error) in
do {
guard let data = data else {
return
}
guard let json = try JSONSerialization.jsonObject(with: data, options: []) as? [[String:AnyObject]] else {
print("No idea")
return
}
for result in json {
if let student = SearchResult(json: result) {
self.results.append(student)
}
}
self.grabData()
} catch let error as NSError {
print(error.debugDescription)
}
}.resume()
}
func grabData() {
DispatchQueue.main.async {
self.listTableView.reloadData()
}
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if(addStudent==false){
let newVC: DetailViewController = segue.destination as! DetailViewController
newVC.result = results[indexN]
newVC._label1 = results[indexN].studentID
newVC._label2 = results[indexN].lastName
newVC._label3 = results[indexN].firstName
newVC._label4 = results[indexN].major
newVC._label5 = results[indexN].year
newVC._label6 = results[indexN].gpa
}
else if(addStudent==true){
let newVC: DetailViewController = segue.destination as! DetailViewController
newVC.addStudent=true
}
}
func Delete(studentID: String) {
let request = NSMutableURLRequest(url: NSURL(string: "http://csmadison.dhcp.bsu.edu/~vjtanksale/cs320/deletestudents.php")! as URL)
request.httpMethod = "POST"
let postString = "StudentId="+studentID
request.httpBody = postString.data(using: String.Encoding.utf8)
let task = URLSession.shared.dataTask(with: request as URLRequest) {
data, response, error in
if error != nil {
print("error=\(error)")
return
}
print("response = \(response)")
let responseString = NSString(data: data!, encoding: String.Encoding.utf8.rawValue)
print("responseString = \(responseString)")
}
task.resume()
}
func refreshTable(){
results.removeAll()
self.listTableView.reloadData()
jsonParser()
self.listTableView.reloadData()
}
func updateSearchResults(for searchController: UISearchController)
{
filteredTableData.removeAll(keepingCapacity: false)
let searchPredicate = NSPredicate(format: "SELF CONTAINS[c] %@", searchController.searchBar.text!)
let array = (results as NSArray).filtered(using: searchPredicate)
filteredTableData = array as! [String]
self.listTableView.reloadData()
}
}
答案 0 :(得分：3)
您收到此错误是因为您尝试在CONTAINS个对象上使用SearchResult谓词，这些谓词不是具有CONTAINS定义概念的集合。此错误在运行时发生，因为NSPredicate在运行时解析并处理其字符串。为此，使用原生的swift设施更为可取：
let searchTerm = searchController.searchBar.text!
let array = results.filter { result in
return result.studentID.contains(searchTerm) ||
result.something.contains(searchTerm) // and so on...
}