转换为 Swift3 错误

Posted 2023-03-15

【中文标题】转换为 Swift3 错误

【英文标题】：Convert to Swift3 error

【发布时间】：2017-03-12 06:28:04

【问题描述】：

Xcode 转换为 Swift 3.0 语法后，出现以下错误：

错误：无法使用类型为“（qos_class_t）”的参数列表调用类型“Int”的初始化程序 DispatchQueue.global(优先级：Int(DispatchQoS.QoSClass.userInitiated.rawValue)).async ^

注意：“Int”的重载存在这些部分匹配的参数列表：(Int64)、(Word)、(UInt8)、(Int8)、(UInt16)、(Int16)、(UInt32)、(Int32)、 (UInt64), (UInt), (Int), (Float), (Double), (Float80), (String, radix: Int), (CGFloat), (NSNumber) DispatchQueue.global(priority: Int(DispatchQoS.QoSClass.userInitiated.rawValue)).async

转换后的语法：

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

    if searchText == "" 
        self.filteredSymbols = self.symbols
        self.alphabeticSymbolCollection.reloadData()
     else 
        DispatchQueue.global(priority: Int(DispatchQoS.QoSClass.userInitiated.rawValue)).async 
            let fs = self.filterContentForSearchText(searchText)
            DispatchQueue.main.async 
                self.filteredSymbols = fs

                self.searchActive = true

                self.alphabeticSymbolCollection.reloadData()
            
        
    

转换前的语法：

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

    if searchText == "" 
        self.filteredSymbols = self.symbols
        self.alphabeticSymbolCollection.reloadData()
     else 
        dispatch_async(dispatch_get_global_queue(Int(QOS_CLASS_USER_INITIATED.rawValue), 0)) 
            let fs = self.filterContentForSearchText(searchText)
            dispatch_async(dispatch_get_main_queue()) 
                self.filteredSymbols = fs

                self.searchActive = true

                self.alphabeticSymbolCollection.reloadData()
            
        
    

【问题讨论】：

How do I dispatch_sync, dispatch_async, dispatch_after, etc in Swift 3?的可能重复

【参考方案1】：

很简单

DispatchQueue.global(qos: .userInitiated).async