闭包
//
// ViewController.swift
// 闭包
//
// Created by 谢泽锋 on 2017/5/10.
// Copyright © 2017年 泽锋. All rights reserved.
//
import UIKit
class TwoViewController: UIViewController {
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
self.dismiss(animated: true, completion: nil);
}
deinit{
print("销毁了");
}
/// 如果在某个类中定义一个属性，那么这个属性必需初始化，否则就会报错
/// 如果暂时不想初始化，那么必须在后面写上❓问号
var finishs:(()->())?;//当前写法代表闭包的返回值可以是nil
override func viewDidLoad() {
super.viewDidLoad()
/*
闭包的写法
1.闭包通过实参传递给函数
2.如果必保湿函数的最后一个参数，那么闭包可以写在函数（）的后面
3.如果函数只接受一个参数，并且这个参数是闭包，那么（）可以省略
*/
weak var weakSelf = self;
loadData {
print("执行完成");
weakSelf?.view.backgroundColor = UIColor.green;
view.backgroundColor = UIColor.orange;
};
loadDataTWO(num: 23 ,finish: {
print("第一种完成");
//循环引用
// view.backgroundColor = UIColor.orange;
// self.view.backgroundColor = UIColor.orange;
weakSelf?.view.backgroundColor = UIColor.orange;
});
//2
loadData() {
print("执行完成");
};
loadDataTWO(num: 23) {
};
//3
loadData {
};
/*闭包的简写
如果闭包没有参数也没有返回值，那么in之前的东西可以删除，包括in
*/
//第一种
// let sc = UIScrollView(frame: CGRect(x: 0, y: 200, width: 400, height: 44));
// sc.backgroundColor = UIColor.red;
// view.addSubview(sc);
// let width = 80;
// let count = 15;
// for i in 0..<count{
// let btn = UIButton();
// btn.backgroundColor = UIColor.orange;
// btn.setTitle("标题\(i)", for: UIControlState.normal);
// btn.frame = CGRect(x: i*width+1, y: 0, width: width, height: 44);
// sc.addSubview(btn);
// }
// sc.contentSize = CGSize(width: width*count, height: 44);
//第二种
// let sc = creatScrollView { () -> Int in
// return 10;
// };
// view.addSubview(sc);
// 第三种
let sc = creatScrollView(btnCount: { () -> Int in
return 10;
}) { (index) -> UIView in
let width = 80;
let btn = UIButton();
btn.backgroundColor = UIColor.orange;
btn.setTitle("标题\(index)", for: UIControlState.normal);
btn.frame = CGRect(x: index*width+1, y: 0, width: width, height: 44);
return btn;
}
view.addSubview(sc);
// Do any additional setup after loading the view, typically from a nib.
}
func creatScrollView(btnCount:()->Int) ->UIScrollView{
let sc = UIScrollView(frame: CGRect(x: 0, y: 200, width: 400, height: 44));
sc.backgroundColor = UIColor.red;
let width = 80;
let count = btnCount();
for i in 0..<count{
let btn = UIButton();
btn.backgroundColor = UIColor.orange;
btn.setTitle("标题\(i)", for: UIControlState.normal);
btn.frame = CGRect(x: i*width+1, y: 0, width: width, height: 44);
sc.addSubview(btn);
}
sc.contentSize = CGSize(width: width*count, height: 44);
return sc;
}
func creatScrollView(btnCount:()->Int,btnwithIndex:(_ index:Int)->UIView) ->UIScrollView{
let sc = UIScrollView(frame: CGRect(x: 0, y: 200, width: 400, height: 44));
sc.backgroundColor = UIColor.red;
let width = 80;
let count = btnCount();
for i in 0..<count{
// let btn = UIButton();
// btn.backgroundColor = UIColor.orange;
// btn.setTitle("标题\(i)", for: UIControlState.normal);
// btn.frame = CGRect(x: i*width+1, y: 0, width: width, height: 44);
// sc.addSubview(btn);
let subview = btnwithIndex(i);
sc.addSubview(subview);
}
sc.contentSize = CGSize(width: width*count, height: 44);
return sc;
}
func loadDataTWO(num:Int, finish:@escaping ()->()) {
print("执行耗时操作")
self.finishs = finish;
finish();
}
func loadData(finish:()->()) {
print("执行耗时操作")
finish();
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
