链式编程最难得地方是想通，实现是如此的简单：
例一： UIAlertController弹窗
🌰🌰：
func showAlert() {
UIAlertController(title: "提示", message: "信息", preferredStyle: .alert)
.addActionTitle(kTitleSure, style: .default) { (action) in
DDLog(action.title)
}
.addActionTitle(kTitleCancell, style: .destructive) { (action) in
DDLog(action.title)
}
.addTextFieldPlaceholder("", handler: { (textfield) in
DDLog(textfield.text)
}).present {
DDLog("present")
}
}
@objc public extension UIAlertController {
///添加 UIAlertAction
func addActionTitle(_ title: String?, style: UIAlertAction.Style, handler: ((UIAlertAction) -> Void)? = nil) -> UIAlertController {
self.addAction(UIAlertAction(title: title, style: style, handler: handler))
return self
}
///添加多个 UIAlertAction
func addActionTitles(_ titles: [String]?, handler: ((UIAlertAction) -> Void)? = nil) -> UIAlertController {
titles?.forEach({ (string) in
let style: UIAlertAction.Style = string == "取消" ? .destructive : .default
self.addAction(UIAlertAction(title: string, style: style, handler: handler))
})
return self
}
///添加 textField
func addTextFieldPlaceholder(_ placeholder: String, handler: ((UITextField) -> Void)? = nil) -> UIAlertController {
self.addTextField { (textField: UITextField) in
textField.placeholder = placeholder
handler?(textField)
}
return self
}
///展示
public func present(_ animated: Bool = true, completion: (() -> Void)? = nil) {
DispatchQueue.main.async {
guard let rootVC = UIApplication.shared.keyWindow?.rootViewController else { return }
rootVC.present(self, animated: animated, completion: completion)
}
}
}
例二：圆角阴影
链式圆角阴影效果图.jpg
🌰🌰：
UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];
[btn setTitle:@"UIButton" forState:UIControlStateNormal];
[btn setTitleColor:UIColor.systemBlueColor forState:UIControlStateNormal];
[self.view addSubview:btn];
btn.nn_borderWidth(1).nn_borderColor(UIColor.systemBlueColor).
conrnerRadius(5).
nn_shadowColor(UIColor.redColor).nn_shadowOpacity(0.8).nn_shadowOffset(CGSizeZero).nn_shadowRadius(5);
btn.frame = CGRectMake(20, 110, 100, 40);
/*
方法 swift 报错;
添加前缀是为了防止和其他视图参数冲突
*/
#import <UIKit/UIKit.h>
NS_ASSUME_NONNULL_BEGIN
@interface UIView (Chain)
/// 圆角半径 默认 0.0
@property(nonatomic, strong, readonly) UIView *(^nn_conrnerRadius)(CGFloat value);
/// 边框颜色 默认 black
@property(nonatomic, strong, readonly) UIView *(^nn_borderColor)(UIColor *value);
/// 边框宽度 默认 0.0
@property(nonatomic, strong, readonly) UIView *(^nn_borderWidth)(CGFloat value);
/// 阴影
/// 阴影颜色 默认 black
@property(nonatomic, strong, readonly) UIView *(^nn_shadowColor)(UIColor *value);
/// 阴影模糊度 默认 0.0
@property(nonatomic, strong, readonly) UIView *(^nn_shadowRadius)(CGFloat value);
/// (0~1] 默认 0.0
@property(nonatomic, strong, readonly) UIView *(^nn_shadowOpacity)(CGFloat value);
/// 阴影偏移方向和距离 默认 {0.0，0.0}
@property(nonatomic, strong, readonly) UIView *(^nn_shadowOffset)(CGSize value);
/// 图层
@property(nonatomic, strong, readonly) UIView *(^nn_zPosition)(CGFloat value);
@end
#import "UIView+Chain.h"
@implementation UIView (Chain)
- (UIView * _Nonnull (^)(CGFloat))nn_conrnerRadius{
return ^(CGFloat value){
self.layer.cornerRadius = value;
return self;
};
}
- (UIView * _Nonnull (^)(UIColor * _Nonnull))nn_borderColor{
return ^(UIColor *value){
self.layer.borderColor = value.CGColor;
return self;
};
}
- (UIView * _Nonnull (^)(CGFloat))nn_borderWidth{
return ^(CGFloat value){
self.layer.borderWidth = value;
return self;
};
}
- (UIView * _Nonnull (^)(UIColor * _Nonnull))nn_shadowColor{
return ^(UIColor *value){
self.layer.shadowColor = value.CGColor;
return self;
};
}
- (UIView * _Nonnull (^)(CGFloat))nn_shadowOpacity{
return ^(CGFloat value) {
self.layer.shadowOpacity = value;
return self;
};
}
- (UIView * _Nonnull (^)(CGFloat))nn_shadowRadius{
return ^(CGFloat value) {
self.layer.shadowRadius = value;
return self;
};
}
- (UIView * _Nonnull (^)(CGSize))nn_shadowOffset{
return ^(CGSize value) {
self.layer.shadowOffset = value;
return self;
};
}
- (UIView * _Nonnull (^)(CGFloat))nn_zPosition{
return ^(CGFloat value){
self.layer.zPosition = value;
return self;
};
}
@end
例三：计算器加减乘除
let cal = Calculator()
cal.add(5).add(8).print().multiply(2).print().divide(3).print()
2020-09-06 22:13:36.770 SwiftTemplet[18682:14020939] 计算结果: 13
2020-09-06 22:13:36.771 SwiftTemplet[18682:14020939] 计算结果: 26
2020-09-06 22:13:36.771 SwiftTemplet[18682:14020939] 计算结果: 8.666666666666666
#import <UIKit/UIKit.h>
NS_ASSUME_NONNULL_BEGIN
@interface Calculator : NSObject
//计算结果
@property(nonatomic, assign) CGFloat result;
///在结果上加
@property(nonatomic, strong, readonly) Calculator *(^add)(CGFloat);
///在结果上减
@property(nonatomic, strong, readonly) Calculator *(^sub)(CGFloat);
///在结果上乘
@property(nonatomic, strong, readonly) Calculator *(^multiply)(CGFloat);
///在结果上除
@property(nonatomic, strong, readonly) Calculator *(^divide)(CGFloat);
///清零
-(Calculator *)clear;
///打印结果
-(Calculator *)print;
@end
NS_ASSUME_NONNULL_END
#import "Calculator.h"
@implementation Calculator
-(instancetype)init{
if (self = [super init]) {
self.result = 0;
}
return self;
}
-(Calculator *(^)(CGFloat))add{
return ^(CGFloat value){
self.result += value;
return self;
};
}
-(Calculator *(^)(CGFloat))sub{
return ^(CGFloat value){
self.result -= value;
return self;
};
}
- (Calculator * _Nonnull (^)(CGFloat))multiply{
return ^(CGFloat value){
self.result *= value;
return self;
};
}
- (Calculator * _Nonnull (^)(CGFloat))divide{
return ^(CGFloat value){
self.result /= value;
return self;
};
}
-(Calculator *)clear{
self.result = 0;
return self;
}
-(Calculator *)print{
NSLog(@"计算结果: %@\n", @(self.result));
// NSLog(@"计算结果:%.2f\n", self.result);
return self;
}
@end
仿 Masonry
#import "Calculator.h"
NS_ASSUME_NONNULL_BEGIN
@interface Calculator (Chain)
+ (CGFloat)nn_makeCalcuclate:(void(^)(Calculator *))block;
@end
NS_ASSUME_NONNULL_END
#import "Calculator+Chain.h"
@implementation Calculator (Chain)
+ (CGFloat)nn_makeCalcuclate:(void(^)(Calculator *))block{
Calculator *manager = [[Calculator alloc] init];
block(manager);
return manager.result;
}
@end
网友评论