iOS开发之本地图片推送

序言

今天闲着，我就把之前项目中做过的一些技术点写出来分享下，希望能帮到人。第一次写，写的不好的话请多多包涵哈！！！

背景

带上图片的推送使用范围很广，既可以是安防产品的报警推送时附带图片，又可以是广告时的宣传等等。

1.iOS 10以后才可以在推送中附加图片

2.推送可以是本地推送和后台推送

3.后台推送返回的图片是一段URL，当本地下载到临时目录使用后会自动删除，当然你也可以自己本地下载并保存

步骤

1.导入头文件并遵守协议

#import 
@interface AppDelegate ()

2.实现

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    // Override point for customization after application launch.
   //如果你想自己手动推送，可以在ViewController里加个按钮发送以下通知事件
  //  [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(pushAction) name:@"pushWithPhoto" object:nil];
    
    [self pushAction];
    return YES;
}
-(void)pushAction
{
    //1.申请权限
        [[UNUserNotificationCenter currentNotificationCenter] requestAuthorizationWithOptions:UNAuthorizationOptionBadge | UNAuthorizationOptionSound | UNAuthorizationOptionAlert completionHandler:^(BOOL granted, NSError * _Nullable error){}];
    
        //2.初始化通知
        UNMutableNotificationContent *content = [[UNMutableNotificationContent alloc] init];
        content.badge = @1;
        content.title = @"通知的标题";
        content.body = @"通知的内容";   //如果不填写body,则不会弹出通知
        UNNotificationSound *sound = [UNNotificationSound defaultSound]; //系统的声音
        content.sound = sound;
    
        //3.下载图片
        //3.1获取图片
        NSString * imageUrlString = @"https://img1.doubanio.com/img/musician/large/22817.jpg";
        NSData *imageData = [NSData dataWithContentsOfURL:[NSURL URLWithString:imageUrlString]];
        
        //3.2图片保存到沙盒
        NSString *documentPath = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES).firstObject;
        NSString *localPath = [documentPath stringByAppendingPathComponent:@"localNotificationImage.jpg"];
        [imageData writeToFile:localPath atomically:YES];
        
        //3.3设置通知的attachment(附件)
        if (localPath && ![localPath isEqualToString:@""]) {
            UNNotificationAttachment * attachment = [UNNotificationAttachment attachmentWithIdentifier:@"photo" URL:[NSURL URLWithString:[@"file://" stringByAppendingString:localPath]] options:nil error:nil];
            if (attachment) {
                content.attachments = @[attachment];
            }
        }
        
        //4.设置触发模式
        UNTimeIntervalNotificationTrigger *trigger = [UNTimeIntervalNotificationTrigger triggerWithTimeInterval:2 repeats:NO];
        
        //5.推送
        UNNotificationRequest *request = [UNNotificationRequest requestWithIdentifier:@"pusswzy" content:content trigger:trigger];
        
        UNUserNotificationCenter *center = [UNUserNotificationCenter currentNotificationCenter];
        [center addNotificationRequest:request withCompletionHandler:^(NSError * _Nullable error) {
            if (error) {
                NSLog(@"%@", error);
            }
        }];
        
        //设置代理
        center.delegate = self;
}
#pragma mark - iOS10 收到通知（本地和远端） UNUserNotificationCenterDelegate
- (void)userNotificationCenter:(UNUserNotificationCenter *)center willPresentNotification:(UNNotification *)notification withCompletionHandler:(void (^)(UNNotificationPresentationOptions))completionHandler{
    // 有这句，推送会在前台展示
    completionHandler(UNNotificationPresentationOptionAlert|UNNotificationPresentationOptionSound);
}

以上是简单的本地推送图片的实现步骤，你直接复制代码就可以使用。下一篇将会介绍远程推送图片方面的。
参考资料：
iOS10本地消息推送下载的图片