将Swift Closures作为值添加到Swift字典

问题描述

我想创建一个Swift字典，它包含String类型作为其键和Closures作为其值。下面是我的代码，但它给我的错误：

'@ lvalue不等于'（String，（） - > Void）'

  class CommandResolver {
 private var commandDict：[String：（） - >空虚]！ 
 
 init（）{
 self.setUpCommandDict（）; 
} 
 
 func setUpCommandDict（）{
 
 self.commandDict [OpenAssessment_1] = {
 println（I am inside inside closure）; 
 
} 
} 
} 
  

看看关于StackOverflow关于字典中的闭包的其他问题，但它不给我任何满意的答案。

解决方案

如果你在 init 在调用你的设置函数之前，它应该工作：

  class CommandResolver {
 private var commandDict： [String：（） - > Void] 
 
 init（）{
 commandDict = [：] 
 setUpCommandDict（）
} 
 
 func setUpCommandDict（）{
 commandDict [OpenAssessment_1] = {
 println（I am inside closure）
} 
} 
} 
  / pre> 
I want to create a Swift dictionary that holds String type as its keys and Closures as its values. Following is the code that I have but it gives me the error:

'@lvalue is not identical to '(String, () -> Void)'
class CommandResolver {
     private var commandDict:[String : () -> Void]!

     init() {
         self.setUpCommandDict();
     }

     func setUpCommandDict() {

         self.commandDict["OpenAssessment_1"] = {
                 println("I am inside closure");

          }
      }
  }
I tried looking at other question on StackOverflow regarding closures in dictionaries but it does not give me any satisfactory answer. So I would really appreciate some help here.
 解决方案 
If you initialize your dictionary in your init before calling your setup function, it should work:
class CommandResolver {
    private var commandDict: [String: () -> Void]

    init() {
        commandDict = [:]
        setUpCommandDict()
    }

    func setUpCommandDict() {
        commandDict["OpenAssessment_1"] = {
            println("I am inside closure")
        }
    }
}
                        
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