我的目标是在一个 viewController 上有 3 个 pickerView。每个 pickerView 将根据先前保存的设置列出不同的数据源，这些设置是从数据库中提取的。我已经根据使用如下所示的 switch 语句从数据库中提取的值设置了数据源。
在确实加载的 View 中，连同我设置的选择器的代表，我有:
switch firstValuePulled {
case "Animals":
var pickerNumber1 = [["Cat", "Dog", "Bird", Fish],["1","2","3","4","5","6"]]
case "Sports":
var pickerNumber1 = [["Basketball", "Hockey", "Baseball", "Tennis", "Football"],["1","2","3","4","5","6"]]
default:
var pickerNumber1 = [["Apple", "Orange", "Peach"],["1","2","3","4","5","6"]]
}
switch second ValuePulled {
case "Animals":
var pickerNumber2 = [["Cat", "Dog", "Bird", Fish],["1","2","3","4","5","6"]]
case "Sports":
var pickerNumber2 = [["Basketball", "Hockey", "Baseball", "Tennis", "Football"],["1","2","3","4","5","6"]]
default:
var pickerNumber2 = [["Apple", "Orange", "Peach"],["1","2","3","4","5","6"]]
}
switch thirdValuePulled {
case "Animals":
var pickerNumber1 = [["Cat", "Dog", "Bird", Fish],["1","2","3","4","5","6"]]
case "Sports":
var pickerNumber1 = [["Basketball", "Hockey", "Baseball", "Tennis", "Football"],["1","2","3","4","5","6"]]
default:
var pickerNumber1 = [["Apple", "Orange", "Peach"],["1","2","3","4","5","6"]]
}
至于picker delegates，报错如下“Use of unresolved identifier 'pickerNumber1'”、“Use of unresolved identifier 'pickerNumber2'”等，难道是switch语句没有正确执行，因此delegates没有显示选择器的值？
func numberOfComponents(in pickerView: UIPickerView) -> Int {
return 2
}
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
if (pickerView.tag == 1){
return pickerNumber1[component].count;
} else if (pickerView.tag == 2){
return pickerNumber2[component].count;
} else {
return pickerNumber3[component].count;
}
}
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String! {
if (pickerView.tag == 1){
return pickerNumber1[component][row]
} else if (pickerView.tag == 2){
return pickerNumber2[component][row]
} else {
return pickerNumber3[component][row]
}
}
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
if (pickerView.tag == 1){
eventOneValue = pickerNumber1[0][pickerView.selectedRow(inComponent: 0)]
eventOneNumber = pickerView.selectedRow(inComponent: 1) + 1
print(eventOneValue)
} else if (pickerView.tag == 2) {
eventTwoValue = pickerNumber2[0][pickerView.selectedRow(inComponent: 0)]
eventTwoNumber = pickerView.selectedRow(inComponent: 1) + 1
print(eventTwoValue)
} else {
eventThreeValue = pickerNumber3[0][pickerView.selectedRow(inComponent: 0)]
eventThreeNumber = pickerView.selectedRow(inComponent: 1) + 1
print(eventThreeValue)
}
}
最佳答案
这是因为你创造了 pickerNumber1、pickerNumber2 在 switch 语句的范围内局部使用，而 U 在选择器委托(delegate)中使用! 你必须在类里面创建它们并像那样在 Switch 中设置它的值
类你的类名{
var pickerNumber1:Array = []
var pickerNumber2:Array = []
然后 Switch 语句将其用作
switch firstValuePulled { 案例“动物”: pickerNumber1 = [["猫", "狗", "鸟", 鱼],["1","2","3","4","5","6"]]
case "Sports":
pickerNumber1 = [["Basketball", "Hockey", "Baseball", "Tennis", "Football"],["1","2","3","4","5","6"]]
default:
pickerNumber1 = [["Apple", "Orange", "Peach"],["1","2","3","4","5","6"]]
}
切换第二个 ValuePulled { 案例“动物”: pickerNumber2 = [["猫", "狗", "鸟", 鱼],["1","2","3","4","5","6"]]
case "Sports":
pickerNumber2 = [["Basketball", "Hockey", "Baseball", "Tennis", "Football"],["1","2","3","4","5","6"]]
default:
pickerNumber2 = [["Apple", "Orange", "Peach"],["1","2","3","4","5","6"]]
}
切换 thirdValuePulled { 案例“动物”: pickerNumber1 = [["猫", "狗", "鸟", 鱼],["1","2","3","4","5","6"]]
case "Sports":
pickerNumber1 = [["Basketball", "Hockey", "Baseball", "Tennis", "Football"],["1","2","3","4","5","6"]]
default:
pickerNumber1 = [["Apple", "Orange", "Peach"],["1","2","3","4","5","6"]]
}
然后在选择器委托(delegate)中使用它们!
关于Swift 3.0 多个选择器 View 无法识别数据源变量，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/43929278/