- block是iOS4.0时才出现的技术
一.闭包
- 网络请求工具类,封装方法时,把闭包当参数封装,并在内部执行,这样外面就能拿到闭包的参数,相当用传值了
import UIKit
import AFNetworking
enum RequestType {
case GET
case POST
}
class NetworkTools: AFHTTPSessionManager {
// 1.将NetworkTools设置成单例
static let shareIntance : NetworkTools = {
let tools = NetworkTools()
tools.responseSerializer.acceptableContentTypes?.insert("text/html")
return tools
}()
}
// MARK:- 封装网络请求
extension NetworkTools {
func request(requestType : RequestType, urlString : String, parameters : [String : AnyObject], finished : (result : AnyObject?, error : NSError?) -> ()) {
// 1.定义成功后的闭包
let successCallBack = { (task : NSURLSessionDataTask, result : AnyObject?) -> Void in
finished(result: result, error: nil)
}
// 2.定义失败后的闭包
let failureCallBack = { (task : NSURLSessionDataTask?, error : NSError) -> Void in
finished(result: nil, error: error)
}
// 3.发送网络请求
if requestType == .GET {
GET(urlString, parameters: parameters, progress: nil, success: successCallBack, failure: failureCallBack)
} else {
POST(urlString, parameters: parameters, progress: nil, success: successCallBack, failure: failureCallBack)
}
}
}
- 使用: 看下段代码第3条,调用上面封装方法时就相当于拿到了数据
// MARK:- 请求首页数据
extension NetworkTools {
func loadHomeData(finished : (result : [[String : AnyObject]]?, error : NSError?) -> ()) {
// 1.获取请求的URLString
let urlString = "http://mobapi.meilishuo.com/2.0/twitter/popular.json"
// 2.获取请求的参数
let parameters = ["offset" : "0", "limit" : "30", "access_token" : "b92e0c6fd3ca919d3e7547d446d9a8c2"]
// 3.发送网络请求
request(.GET, urlString: urlString, parameters: parameters) { (result, error) -> () in
/**********此处就可以拿到闭包的参数,就相当于把数据传出来了******/
// 1.判断是否有错误
if error != nil {
finished(result: nil, error: error)
}
// 2.获取结果
guard let result = result as? [String : AnyObject] else {
finished(result: nil, error: NSError(domain: "data error", code: -1011, userInfo: nil))
return
}
// 3.将结果回调
finished(result: result["data"] as? [[String : AnyObject]] , error: nil)
}
}
}
二. 代理
- HostView
#import <UIKit/UIKit.h>
@protocol HostViewDelegate <NSObject>
- (void)pushViewControllerWith:(UIButton *)btn;
@end
@interface HostView : UIView
@property (nonatomic, weak) id<HostViewDelegate>Delegate;
@end
- (void)clickButtonWith:(UIButton *)btn
{
//int tag = (int)btn.tag;
// self.block(tag); //此处是block写法
if ([self.Delegate respondsToSelector:@selector(pushViewControllerWith:)] ) {
[self.Delegate pushViewControllerWith:btn];
}
}
- 另一个控制器MineViewController中,这样就拿到传递过来的tag值
@interface MineViewController ()<HostViewDelegate>
hostView.Delegate = self;
- (void)pushViewControllerWith:(UIButton *)btn
{
UIViewController *vc = self.controllerArray[btn.tag];
NSLog(@"%@+++++++",vc);
[self.navigationController pushViewController:vc animated:YES];
}
三. block
3.1思想
-
A类中有个属性block,block带一个参数,
- 并在A类就执行了block(a)
B类中 要跳转控制器到A类的控制器, 使用
A.block(int) = ^(int a){
这样 在此括号里就能拿到 A 类传递过来的a值 ,实现了代理传值方法
}
3.2实例
- HostView中
#import <UIKit/UIKit.h>
//@protocol HostViewDelegate <NSObject>
//
//- (void)pushViewControllerWith:(UIButton *)btn;
//
//@end
@interface HostView : UIView
//@property (nonatomic, weak) id<HostViewDelegate>Delegate;
@property (nonatomic, strong) void(^block)(int);
@end
- (void)clickButtonWith:(UIButton *)btn
{
int tag = (int)btn.tag;
self.block(tag);
// if ([self.Delegate //此处是delegate写法 respondsToSelector:@selector(pushViewControllerWith:)] ) {
// [self.Delegate pushViewControllerWith:btn];
// }
}
- 另一个控制器MineViewController中,这样就拿到传递过来的tag值
hostView.block = ^( int tag ){
UIViewController *vc = self.controllerArray[tag];
NSLog(@"%@+++++++",vc);
[self.navigationController pushViewController:vc animated:YES];
};
