Objective c 如何以编程方式打开NSComboBox'；谁的名单？

我已经在这附近呆了一段时间了。。我认为这应该是一项简单的任务，但它不是

我想做的是，当用户单击组合框时，显示组合框的列表，但不是特别在按钮中

有什么想法吗？

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提前谢谢

NSCOMBOX不是设计成这样工作的。因为用户可能想要编辑控件中的文本，所以他们需要能够在不意外弹出选项的情况下单击它

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您需要将nsComboxCell子类化并更改此行为。。。但是你会有一个标准外观的控件，它不会以标准的方式运行。如果您决定这样做，请查看的开源版本。有趣的方法似乎是-popupforComboxCell:和friends.

这个答案符合问题的标题，但不符合问题本身。Omer想触摸文本字段并弹出框

此解决方案在用户输入文本时显示弹出窗口

我从cocoabuilder上找到了这个答案。我把他的密码转寄到这里。谢谢你，简

我在

控制文本didchange:

方法中使用了此代码

- (void) controlTextDidChange:(NSNotification *) aNotification {
  NSTextField *textField = [aNotification object];
  NSString *value = [textField stringValue];
  NSComboBox *box = [self comboBox];
  if (value == nil || [value length] == 0) {
    if ([box isExpanded]) { [box setExpanded:NO]; }
  } else {
    if (![box isExpanded]) { [box setExpanded:YES]; }
  }
}

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您可以使用以下代码行：

 [(NSComboBoxCell*)self.acomboBox.cell performSelector:@selector(popUp:)];

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感谢上面提到的jmoody和Jens Alfke。下面是上述解决方案的快速翻译

import Cocoa

类别ccomboxex:NSComboBox

{

override func drawRect(dirtyRect: NSRect) {
    super.drawRect(dirtyRect)
        // Drawing code here.

       }

func isExpanded() -> Bool{

    if let ax:AnyObject? = NSAccessibilityUnignoredDescendant(self) {
        if ax!.accessibilityAttributeValue(NSAccessibilityExpandedAttribute) != nil {
            return true
        }
    }
    return false
}

func setExpanded (bExpanded:Bool) {

    if let ax:AnyObject? = NSAccessibilityUnignoredDescendant(self) {
       ax!.accessibilitySetValue(NSNumber(bool: bExpanded), forAttribute: NSAccessibilityExpandedAttribute)
    }

 }



}

放

进入

这就是我的结局。谢谢@Ahmed Lotfy

这是完整的代码，它在OSX 10.11上对我有效

override func controlTextDidChange(obj: NSNotification) {
        if let comboBoxCell = self.comboBox.cell as? NSComboBoxCell {
            comboBoxCell.performSelector(Selector("popUp:"))
        }
}

如果NSComboBox的列表已展开，则返回

true

comboBox.cell?.isAccessibilityExpanded() ?? false

打开NSComboBox的列表

comboBox.cell?.setAccessibilityExpanded(true)

comboBox.cell?.setAccessibilityExpanded(false)

关闭NSComboBox的列表

comboBox.cell?.setAccessibilityExpanded(true)

comboBox.cell?.setAccessibilityExpanded(false)

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参考..

基于我编写的其他答案（使用Xcode 10.2.1和Swift 5进行测试）。它使用了相同的想法，但略短一些

// Put this extension for NSComboBox somewhere in your project

import Cocoa

public extension NSComboBox {

    var isExpanded: Bool{
        set {
            cell?.setAccessibilityExpanded(newValue)
        }
        get {
            return cell?.isAccessibilityExpanded() ?? false
        }
    }
}

// Set your corresponding NSViewController as NSComboBoxDelegate 
// in the storyboard and add this piece of code 
// to expand the combobox when the user types

class MyViewController: NSViewController, NSComboBoxDelegate {

    func controlTextDidChange(_ notification: Notification) {
        guard let comboBox = notification.object as? NSComboBox else { return }
        if comboBox.isExpanded == false {
            comboBox.isExpanded = true
        }
    }
}

// Put this extension for NSComboBox somewhere in your project

import Cocoa

public extension NSComboBox {

    var isExpanded: Bool{
        set {
            cell?.setAccessibilityExpanded(newValue)
        }
        get {
            return cell?.isAccessibilityExpanded() ?? false
        }
    }
}

// Set your corresponding NSViewController as NSComboBoxDelegate 
// in the storyboard and add this piece of code 
// to expand the combobox when the user types

class MyViewController: NSViewController, NSComboBoxDelegate {

    func controlTextDidChange(_ notification: Notification) {
        guard let comboBox = notification.object as? NSComboBox else { return }
        if comboBox.isExpanded == false {
            comboBox.isExpanded = true
        }
    }
}