实施LocalNotification

Question

我是Xamarin的新手。我正在寻找一种方法来实现我的crossform应用程序的本地通知。

以下是我从Xamarin网站获得的代码：https://developer.xamarin.com/guides/android/application_fundamentals/notifications/local_notifications_in_android/

// Instantiate the builder and set notification elements:
Notification.Builder builder = new Notification.Builder (this)
    .SetContentTitle ("Sample Notification")
    .SetContentText ("Hello World! This is my first notification!")
    .SetSmallIcon (Resource.Drawable.ic_notification);

// Build the notification:
Notification notification = builder.Build();

// Get the notification manager:
NotificationManager notificationManager =
    GetSystemService (Context.NotificationService) as NotificationManager;

// Publish the notification:
const int notificationId = 0;
notificationManager.Notify (notificationId, notification);

我只是想知道我怎么做，当我按下按钮时主动通知

先谢谢。

Answer 1

您正在寻找AddAction(Notification.Action action)功能。 Notification.Action必须由Notification.Action.Builder

创建

基本示例：

var actionBuilder = new Notification.Action.Builder(Resource.Drawable.ic_notification_action, "Click me", someActionIntent);

// Instantiate the builder and set notification elements:
Notification.Builder builder = new Notification.Builder (this)
    .SetContentTitle ("Sample Notification")
    .SetContentText ("Hello World! This is my first notification!")
    .SetSmallIcon (Resource.Drawable.ic_notification)
    .AddAction(actionBuilder.Build());

请注意，您必须首先初始化someActionIntent。

Answer 2

如果您正在寻找显示本地通知的统一方式，请使用James Montemagno的以下插件。在PCL和Android项目中安装插件。 Local Notifications Plugin

private void MyButtonClick(object sender, EventArgs e)
{
    CrossLocalNotifications.Current.Show("title", "body");
}

Answer 3

对于Xamarin.Forms应用，您需要DependencyService才能完成此任务：

1. 在您的PCL中创建一个界面（ILocalNotificationService.cs）：

   public interface ILocalNotificationService
   {
       void ShowLocalNotification(string title, string text, string icon);
   }
   

2. 在本地Xamarin.Android项目中，创建一个类（LocalNotificationServiceImplementation.cs）以实现ILocalNotificationService并从Java.Lang.Object继承，然后在顶部添加assembly:Dependency属性命名空间：

   [assembly:Dependency(typeof(LocalNotificationServiceImplementation))]
   namespace LocalNotificationDemo.Droid
   {
       public class LocalNotificationServiceImplementation :Java.Lang.Object, ILocalNotificationService
       {
           public void ShowLocalNotification(string title, string text, string icon)
           {
   
               // Instantiate the builder and set notification elements:
               Notification.Builder builder = new Notification.Builder(Forms.Context)
                   .SetContentTitle(title)
                   .SetContentText(text);
   
               if (icon == "ic_notification")
               {
                   builder.SetSmallIcon(Resource.Drawable.ic_notification);
               }
   
               // Build the notification:
               Notification notification = builder.Build();
   
               // Get the notification manager:
               NotificationManager notificationManager =
                   Forms.Context.GetSystemService(Context.NotificationService) as NotificationManager;
   
               // Publish the notification:
               const int notificationId = 0;
               notificationManager.Notify(notificationId, notification);
           }
       }
   }
   

3. 在PCL的按钮点击事件处理程序中，调用依赖服务，如下所示：

   private void Button_Clicked(object sender, EventArgs e)
   {
       DependencyService.Get<ILocalNotificationService>().ShowLocalNotification("My Title", "Hello World! This is my first notification!", "ic_notification");
   }
   

注意：Xamarin调用Dependency Service类的默认构造函数，因此上下文不能通过构造函数传递，但xamarin提供Forms.Context，它代表活动的当前上下文。