1.頁面返回的時候,將取消網絡請求。網絡
場景應用:在一個界面進行多個請求的時候,用戶有可能在網路請求沒有完成時點擊了返回按鈕,session
此時ViewController不會立刻銷燬,要等到網絡請求返回並執行完畢block後纔會銷燬ViewController。atom
場景應用:在流程界面獲取關聯流程數據的條數,在流程界面請求完數據後將數據傳過去,若沒有spa
完場,則在關聯流程界面再次請求數據,須要將上一界面的網絡請求取消rem
#import <UIKit/UIKit.h>it
@interface BaseViewController : UIViewControllerio
//記錄將須要在退出ViewController取消的請求
- (void)addSessionDataTask:(NSURLSessionDataTask *)task;table
//移除已經請求成功的請求
- (void)removeSessionDataTask:(NSURLSessionDataTask *)task;import
//取消全部的請求
- (void)cancelAllSessionDataTask;請求
@end
#import "BaseViewController.h"
@interface BaseViewController ()
@property (nonatomic, strong) NSMutableArray<NSURLSessionDataTask *> *sessionDataTaskMArr;
@end
@implementation BaseViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view.
}
- (NSMutableArray *)sessionDataTaskMArr {
if (_sessionDataTaskMArr == nil) {
_sessionDataTaskMArr = [NSMutableArray array];
}
return _sessionDataTaskMArr;
}
- (void)addSessionDataTask:(NSURLSessionDataTask *)task {
if (task == nil) {
return;
}
[self.sessionDataTaskMArr addObject:task];
}
- (void)removeSessionDataTask:(NSURLSessionDataTask *)task {
[self.sessionDataTaskMArr removeObject:task];
}
- (void)cancelAllSessionDataTask {
if (self.sessionDataTaskMArr.count <= 0) {
return;
}
for (NSURLSessionDataTask *dataTask in self.sessionDataTaskMArr) {
if (dataTask.state == NSURLSessionTaskStateRunning || dataTask.state == NSURLSessionTaskStateSuspended ) {
[dataTask cancel];
}
}
[self.sessionDataTaskMArr removeAllObjects];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}