效果显示数下图：
1、初始化
pickerView.center = self.view.center
//将dataSource设置成自己
pickerView.dataSource=self
//将delegate设置成自己
pickerView.delegate=self
//设置选择框的默认值
pickerView.selectRow(2,inComponent:0,animated:true)
pickerView.selectRow(4,inComponent:1,animated:true)
pickerView.selectRow(5,inComponent:2,animated:true)
self.view.addSubview(pickerView)2、代理方法的实现
func numberOfComponents(in pickerView: UIPickerView) -> Int {
return 3
}
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
return 9
}
//设置选择框个选项的内容
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
return String(row)+"_"+String(component)
}3、触摸按钮时，获得被选中的索引
func btnClick() {
let strs = String(pickerView.selectedRowInComponent(0)) + "_" + String(pickerView.selectedRowInComponent(1)) + "_" + String(pickerView.selectedRowInComponent(2))
let alertControllers = UIAlertController(title: "系统提示",message: strs,preferredStyle: .alert)
let cancelActions = UIAlertAction(title: "取消",style: .cancel,handler: nil)
let okActions = UIAlertAction(title: "确定",style: .default,handler: nil)
alertControllers.addAction(cancelActions)
alertControllers.addAction(okActions)
self.present(alertControllers, animated: true, completion: nil)
}4、调整选择框的尺寸
func pickerView(pickerView: UIPickerView, widthForComponent component: Int) -> CGFloat {
if 0 == component
{
//第一列变宽
return 100
}else
{
//第二、三列变宽
return 50
}
}
5、设置行高
func pickerView(_ pickerView: UIPickerView, rowHeightForComponent component: Int) -> CGFloat {
return 40
}6、检测响应选项的选择状态
func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
//将在滑动停止后触发，并打印出选中列和行索引
print(component)
print(row)
}7,将图片作为选择框选项
//将图片作为选择框选项
//选择框选择的内容，除了可以是字符串类型的，还可以是任意UIView类型的元素，比如我们将选项内容设置为图片：
func pickerView(_ pickerView: UIPickerView, viewForRow row: Int, forComponent component: Int, reusing view: UIView?) -> UIView {
let image = UIImage(named:"11")
let himageView = UIImageView()
himageView.frame = CGRect(x:5,y:0,width:30,height:30)
himageView.image = image
return himageView
}
点击按钮，显示被选中的行数，效果图如下：
作者：稻草人11223
