selector

问题 A typical call to performSelectorOnMainThread: looks like this: [target performSelectorOnMainThread:action withObject:foo waitUntilDone:NO]; where "result" is an argument passed to "action". A corresponding action would be: - (void)doSomethingWithThing1:(id *)thing1 What is the correct syntax for calling an action that takes > 1 argument? Such as: - (void)doSomethingWithThing1:(id *)thing1 andThing2(id *)thing2 andAlsoThing3(id *)thing3 [target performSelectorOnMainThread:action withObject:??

问题 I have a method with multiple variables: -(void) showImg:(UIBarButtonItem *)sender string1:(NSString *) string2:(NSString *); I want to send NSString values (As this function is used for multiple elements). This is how I add my action when no parameters are needed: [myButton addTarget:self action:@selector(showImg) forControlEvents: UIControlEventTouchUpInside]; I tried adding parameters within the @selector like this: [myButton performSelector @selector(showImg:string1:string2::) withObject:

问题 I'm trying to create multiple buttons with a for loop, but I'm having problems using the (sender:) function. I have the following code func setUpButtons(){ for i in 1...3 { let btn: UIButton = UIButton(frame: CGRect(x: 100, y: 100, width: 75, height: 100)) btn.center = CGPoint(x: 20 + 100.0 * CGFloat(i), y: 200) btn.backgroundColor = UIColor.green btn.setTitle("Click Me", for: UIControlState.normal) btn.addTarget(self, action: Selector(("buttonAction:")), for: UIControlEvents.touchUpInside)

问题 I'm writing a NIO server and would like to response on a user request, i.e. write some data to a channel. Selector selector; //... if(selector.selectNow() != 0){ if(key.isReadable()){ SocketChannel channel = key.channel(); //read some data //respond key.interestOps(SelectionKey.OP_WRITE) //How to add the key to a selected set? } } After reading some data I want to respond. It means I need to add OP_WRITE to the key and then add the key to Selected-keys set and then write some content to a

问题 In converting from Swift 2.3 to Swift 3, I receive the error above for the following line of code: var contactButton: UIBarButtonItem {return self.CustomRightItem("icon-nav-nls-contact", target: self, action: nil)} The problem is on the nil action. I've tried using and empty selector: #selector() and ```#selector(nil) both to no avail. How can I handle a nil action in Swift 3? 回答1: This is clearly placeholder code for a later action, so use a placeholder function where the code will

问题 I am trying to learn Swift -- current task is making a simple menu for a Mac app from an array of objects that contain strings. The problem now is how to pass the selector, which in the array is a string, but in the code is a function. The class is class menuArrayObject { var title: String = "" var subMenuTitles: [String] = [] var subMenuSelectors: [String] = [] } Here is my code for index2 in 0...counter2 - 1 { let subMenuTitle = arrayObject.subMenuTitles[index2] let subMenuSelector =

问题 I just learned how to do the 'document.getElementById' counterpart in jQuery (and it's more powerful). My question is, is it okay to use it everytime or every line of code? Here's how I use it now: $('#MyParentElement').html('<tr id="' + $('#MyElement').val() + '"><td>' + $('#MyElement').val() + '</td></tr>'; Isn't better if I do something like using a variable to reference the object? var x = $('#MyElement'); $('#MyParentElement').html('<tr id="' + x.text() + '"><td>' + x.text() + '</td></tr

问题 This was asked many times, I know but this is different! I made this: When you click on the minus icon, the column should disappear, this worked with php, but the code is a mess and I would like to get this working with jQuery, i found some other threads that showed me this: $("#minus").click(function() { $("#table td:nth-child(2),th:nth-child(2)").hide(); }); After a while I came up with this: var num = $("#columnid").index(); $("#table td:nth-child("+ num +"),th:nth-child("+ num +")").hide(

问题 I am having problem understanding part of the function of "selectors", as described in Apple's guide. I've bolded the parts where I am getting confused: In Objective-C, selector has two meanings. It can be used to refer simply to the name of a method when it’s used in a source-code message to an object. It also, though, refers to the unique identifier that replaces the name when the source code is compiled. Compiled selectors are of type SEL. All methods with the same name have the same

问题 I need a way for jQuery to return all elements that have the css font-family:AvantGardeITCbyBT-Bold, sans-serif; applied to them. I'm thinking the only way of doing this is looping through all elements and checking if this css is applied to it. Seems a slow way of doing it? Is there a way of doing this via a jQuery Selector? 回答1: well, you can extend the jQuery selectors with $(document).ready(function(){ $.extend($.expr[':'], { AvantGardel: function(elem){ var $e = $(elem); return( typeof $e