RxSwift之UI控件UIPickerView扩展的使用

一、基本用法

① 单列的情况

基本用法

• 示例代码：

var pickerView : UIPickerView!
     
// 最简单的pickerView适配器（显示普通文本）
private let stringPickerAdapter = RxPickerViewStringAdapter<[String]>(
    components: [],
    numberOfComponents: {
    
     _,_,_  in 1 },
    numberOfRowsInComponent: {
    
     (_, _, items, _) -> Int in
        return items.count},
    titleForRow: {
    
     (_, _, items, row, _) -> String? in
        return items[row]}
)

// 创建pickerView
pickerView = UIPickerView()
pickerView.frame = CGRect.init(x: 0, y: 100, width: SCREEN_WIDTH, height: 150)
self.view.addSubview(pickerView)
 
// 绑定pickerView数据
Observable.just(["One", "Two", "Tree"])
    .bind(to: pickerView.rx.items(adapter: stringPickerAdapter))
    .disposed(by: disposeBag)
 
// 建立一个按钮，触摸按钮时获得选择框被选择的索引
let button = UIButton(frame:CGRect(x:0, y:0, width:SCREEN_WIDTH, height:50))
button.center = self.view.center
button.backgroundColor = UIColor.purple
button.setTitle("获取信息",for:.normal)
// 按钮点击响应
button.rx.tap
    .bind {
    
     [weak self] in
        self?.getPickerViewValue()
    }
    .disposed(by: disposeBag)
self.view.addSubview(button)


// 触摸按钮时，获得被选中的索引
@objc func getPickerViewValue(){
    
    
    let message = String(pickerView.selectedRow(inComponent: 0))
    let alertController = UIAlertController(title: "被选中的索引为",
                                            message: message, preferredStyle: .alert)
    let okAction = UIAlertAction(title: "OK", style: .cancel, handler: nil)
    alertController.addAction(okAction)
    self.present(alertController, animated: true, completion: nil)
}

② 多列的情况

• 示例代码：

// 创建pickerView
pickerView = UIPickerView()
pickerView.frame = CGRect.init(x: 0, y: 100, width: SCREEN_WIDTH, height: 150)
self.view.addSubview(pickerView)
 
// 绑定pickerView数据
Observable.just([["One", "Two", "Tree"],
                 ["A", "B", "C", "D"]])
    .bind(to: pickerView.rx.items(adapter: stringPickerAdapter))
    .disposed(by: disposeBag)
 
// 建立一个按钮，触摸按钮时获得选择框被选择的索引
let button = UIButton(frame:CGRect(x:0, y:0, width:SCREEN_WIDTH, height:50))
button.center = self.view.center
button.backgroundColor = UIColor.blue
button.setTitle("获取信息",for:.normal)
// 按钮点击响应
button.rx.tap
    .bind {
    
     [weak self] in
        self?.getPickerViewValue()
    }
    .disposed(by: disposeBag)
self.view.addSubview(button)


// 触摸按钮时，获得被选中的索引
@objc func getPickerViewValue(){
    
    
    let message = String(pickerView.selectedRow(inComponent: 0)) + "-"
        + String(pickerView!.selectedRow(inComponent: 1))
    let alertController = UIAlertController(title: "被选中的索引为",
                                            message: message, preferredStyle: .alert)
    let okAction = UIAlertAction(title: "OK", style: .cancel, handler: nil)
    alertController.addAction(okAction)
    self.present(alertController, animated: true, completion: nil)
}

二、修改默认的样式

• 如下所示，将选项的文字修改成橙色，同时在文字下方加上双下划线：

• 要实现这个效果，只需改用 RxPickerViewAttributedStringAdapter 这个可以设置文字属性的适配器即可，示例如下：

var pickerView:UIPickerView!
     
// 设置文字属性的pickerView适配器
private let attrStringPickerAdapter = RxPickerViewAttributedStringAdapter<[String]>(
    components: [],
    numberOfComponents: {
    
     _,_,_  in 1 },
    numberOfRowsInComponent: {
    
     (_, _, items, _) -> Int in
        return items.count}
    ){
    
     (_, _, items, row, _) -> NSAttributedString? in
        return NSAttributedString(string: items[row],
          attributes: [
            NSAttributedString.Key.foregroundColor: UIColor.orange, // 橙色文字
            NSAttributedString.Key.underlineStyle:
                NSUnderlineStyle.double.rawValue,                   // 双下划线
            NSAttributedString.Key.textEffect:
                NSAttributedString.TextEffectStyle.letterpressStyle
        ])
    }

// 创建pickerView
pickerView = UIPickerView()
pickerView.frame = CGRect.init(x: 0, y: 100, width: SCREEN_WIDTH, height: 150)
self.view.addSubview(pickerView)
 
// 绑定pickerView数据
Observable.just(["One", "Two", "Tree"])
    .bind(to: pickerView.rx.items(adapter: attrStringPickerAdapter))
    .disposed(by: disposeBag)

三、使用自定义视图

• 将选项视图改成单纯显示颜色色块的 view，其颜色由传入的值决定：

• 要实现这个效果，只需改用 RxPickerViewViewAdapter 这个可以返回自定义视图的适配器即可。示例如下：

// 设置自定义视图的pickerView适配器
private let viewPickerAdapter = RxPickerViewViewAdapter<[UIColor]>(
    components: [],
    numberOfComponents: {
    
     _,_,_  in 1 },
    numberOfRowsInComponent: {
    
     (_, _, items, _) -> Int in
        return items.count}
    ){
    
     (_, _, items, row, _, view) -> UIView in
        let componentView = view ?? UIView()
        componentView.backgroundColor = items[row]
        return componentView
    }

// 创建pickerView
pickerView = UIPickerView()
pickerView.frame = CGRect.init(x: 0, y: 100, width: SCREEN_WIDTH, height: 150)
self.view.addSubview(pickerView)
 
// 绑定pickerView数据
Observable.just([UIColor.red, UIColor.orange, UIColor.yellow])
    .bind(to: pickerView.rx.items(adapter: viewPickerAdapter))
    .disposed(by: disposeBag)