iOS 應用圖標角標數字權限處理

錯誤訊息

Attempting to badge the application icon but haven't received permission from the user to badge the application

原因

iOS 8 起，應用若要在圖標右上角顯示紅色數字，必須先向用戶請求通知權限（包含 UIUserNotificationTypeBadge）。未獲授權直接設定 applicationIconBadgeNumber 會拋出上述錯誤。

解決代碼

if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 8.0) {
    UIUserNotificationSettings *settings = [UIUserNotificationSettings settingsForTypes:
        (UIUserNotificationTypeSound | UIUserNotificationTypeAlert | UIUserNotificationTypeBadge)
        categories:nil];
    [[UIApplication sharedApplication] registerUserNotificationSettings:settings];
}

後續處理

• 在 AppDelegate 實作 application:didRegisterUserNotificationSettings: 回調，確認用戶允許後再設定 [[UIApplication sharedApplication] setApplicationIconBadgeNumber:數字]。
• 若用戶拒絕，需引導至「設定」手動開啟權限。