未调用Cocoa-NSearchFieldDelegate方法

Question

在NSVIewConroller的视图中，我有一个简单的NSSearchField。并将NSSearchFIeld的委托连接到视图控制器。我已经实现了NSSearchHFieldDelegate方法如下：

- (void)searchFieldDidStartSearching:(NSSearchField *)sender NS_AVAILABLE_MAC(10_11);
{
    NSLog(@"search field did start: %@", sender.stringValue);
}
- (void)searchFieldDidEndSearching:(NSSearchField *)sender NS_AVAILABLE_MAC(10_11);
{
    NSLog(@"search field did end: %@", sender.stringValue);
}

在开始编辑和结束编辑时不会调用这些方法。但是，如果我实现NSControl，则会在相应的事件上调用controlTextDidChange:和control:textShouldBeginEditing:等默认委托。

为什么不调用NSSearchFieldDelegate方法？。。

Answer 1

步骤1：您的控制器类需要从NSSearchFieldDelegate 继承

步骤2：实现以下2种方法

    func searchFieldDidStartSearching(sender: NSSearchField){
        print("searchFieldDidStartSearching (sender.stringValue)")
    }
    func searchFieldDidEndSearching(sender: NSSearchField){
        print("searchFieldDidEndSearching (sender.stringValue)")
    }

步骤3：在viewDidLoad、windowDidLoad和wakeFromNib等中，将搜索字段的委托设置为视图控制器/窗口控制器等

 self.searchField.delegate = self

工作样品如下

//  AppDelegate.swift
//  NSSearchFieldDelegateSampleCode
//  Created by Debasis Das on 27/05/16.
//  Copyright © 2016 Knowstack. All rights reserved.
import Cocoa
@NSApplicationMain
class AppDelegate: NSObject, NSApplicationDelegate, NSSearchFieldDelegate {
    @IBOutlet weak var window: NSWindow!
    @IBOutlet weak var searchField:NSSearchField!
    func searchFieldDidStartSearching(sender: NSSearchField){
        print("searchFieldDidStartSearching (sender.stringValue)")
    }
    func searchFieldDidEndSearching(sender: NSSearchField){
        print("searchFieldDidEndSearching (sender.stringValue)")
    }
    func applicationDidFinishLaunching(aNotification: NSNotification) {
        // Insert code here to initialize your application
        self.searchField.delegate = self
    }
    func applicationWillTerminate(aNotification: NSNotification) {
        // Insert code here to tear down your application
    }

}