Advanced Xamarin Forms [MVVM] Part1

[@kunalshah4177]

What about the onProperty changed ?? u did not continue how it is used later

[@ViniciusSchneiderRS]

Great guy, always explaining very well what is difficult to understand in web pages . Saved me again!

[@HoussemDellai]

+Vinicius Schneider thank you for that bit of Adrenaline :)

[@sourabhchopade9750]

Can you please upload a video on how to use mvvm light(Galasoft) with Xamarin.Form in VS2017.

[@v2k2008]

@Houseem, Thanks a lot.. You've cleared my lots of doubt and explained every piece of code..Keep posting..

[@HoussemDellai]

Thanks for the kind words :)

[@hosnimahdhi6529]

Go ahead, you are the best for starters

[@thomasnielsen7466]

Good presentation, I did not know about the binding context in xaml and advantages.

[@GotHobby]

Would it be good idea to make EmployeesServices a static class? I do not see a need to instantiate it

[@elijos3110]

Hi, thanks for your time, im having troubles showing the list on the maing page, i put a breakpoint on the employeeservices and gets bind properly, but when its showed on the main page shows the list but not with the values we set on the employee services, it only shows the words XamarinDemoapp.ViewModels, not the word i set for example, instead of appears Mohamed Name, shows XamarinDemoapp.ViewModels , any suggestion? thanks .

[@lolwatch3599]

I don't know why I can't using shortcut to auto show list suggest at xaml? What need I do?

[@jorgetinocomx]

Hi Houssem, nice work. I have a question. Where would you put your business logic? I mean, I guess Models have only the Data Representation and ViewModel it´s like glue between Views and Models. But what happen if I have to do some validations or several actions.(business logic)

[@this.developer415]

hello @Houssem Dellai i'm getting error at " PropertyChanged(this,new PropertyChangedEventArgs(propertyName));" this line saying An exception of type 'System.NullReferenceException' occurred in Project.DLL but was not handled in user code

[@luisfbadel]

Thanks a lot. This is exactly what I've been looking for, you are a genius!!

[@josecarlosmacoratti]

Good Job, Houssem I'm learning a lot with your videos

[@ahmadmeithaluny2551]

السلام عليكم كيف ارفع صورة الى ( sql server بواسطة web service )الله يعطيك العافية

[@nitinchavan9933]

I am unable to bind Employee list in xmal code.Application gets crashed every time.

[@topmangarbuja8240]

Exact same problem. here

[@abdourashad7555]

Same My Problem but I reviewed the spilling , I found many errors and finally the problem solved

[@lordmorgoth7]

You may have resolved the issue, I'm answering in order to prevent others to run into the same issue. Remove the ";assembly=XamarinDemoApp" it runs fine for me

[@werdhack]

Why is the GetEmployees method in its own class rather than in the ViewModel?

[@RohitKumar-fn8rr]

what is the difference between SendAsync and PostAsync??

[@jude6196]

I'm not getting the options which u get in ur resharper. I'm using VS 2017.

[@syntaxerror001000]

@Houssem What is the advantage of using mvvm library like mvvmCross?

[@AJ-or5om]

@Houseem I'm using visual studio 2017, the code syntax seem of change. I'm unable to bind to the EmployeeList.

[@EriAirlangga]

Bookmarked. On flight. Will watch later

[@redarismail5777]

Thank you so much for your help, Could you please explain what if we use iObservalebcollection instead of iNotify

[@adeelmalik2642]

AOA i am new in xamrin plz tell me why we use data template and itemtemplate in list view

[@chetanacharya9631]

Thank you sir ! That was very easy to understand !

[@PhillipMwaniki]

Dude you good. Microsoft should put you in MVA

[@edmondikacajBajze]

Hello i made a app in xamarin form my first app my first work in xamarin couze i work in web developper but i have a problem. The problem is this when dhe app run i my phone it need 6 10 sec to open show just white screen or blank screen i install some plugins as connection maps newton.json etc. Please can you explain why my app run slowly and how to fix that problem

[@abdellatifer-razzouqi6058]

how i can , use backgrounding services in xamarin.forms ?

[@jcevangelista4200]

What's the use of the "?" question mark in PropertyChanged method in 12:50?

[@Kendo3065]

PropertyChanged? => if (PropertyChanged != null) { PropertyChanged(...);} Check if PropertyChanged is null, if not invoke PropertyChanged Event Handler.

[@jcevangelista4200]

Is it the same like this? protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null) { var handler = PropertyChanged; if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName)); }

[@Kendo3065]

yeap.

[@jcevangelista4200]

Alright Sir. Thank you so much :)

[@HoussemDellai]

that is it :)

[@pardeepahlawat5983]

Can you make a video, how to read xml file from remote or local place and load the xml data in ListView in Xamarin Forms

[@KenjieMojar]

is there a link to part 2? also is the code behind should be in ViewModel as well? is that possible/recommended?

[@werdhack]

The code behind and its corresponding Xaml are partial classes and cannot be separated into different folders.

[@scarecrowgaming925]

youtube plug-in is not compatible error :-/

[@DarylsWorld]

Thank you so much Houssem!

[@himanshudwivedi533]

@Houseem, Which visual studio you use for development. Also is it necessary the RAM size above 4 GB. I am developing the app using visual studio community 2015, I am facing problem while deploying window UWP app on emulator it displays error "Not enough memory available in the system to start an emulator that uses 512 MB startup RAM"

[@HoussemDellai]

You can work with 4 GB of RAM, but you'll have to close any program you are not using, especially Chrome windows :)

[@jcevangelista4200]

Does it matter if i write my code in .xaml or in .xaml.cs format? Thank you for the answer.

[@markdeanilvicente7257]

It's the same output but it's preferable to write it on xaml. Some code can be write in xaml.cs but just write it in minimal.

[@nadaalangari7020]

السلام عليكم فيه اداه كنت منزلها باحد مقاطعك اللي هي تسهل عليك كتابه الاكواد كنت بنزلها ونسيت اسمها وبحثت بالمقاطع وضيعت المقطع مالقيتها ممكن تكتب لي اسم الاداه

[@ansbabgi409]

Resharper

[@mayuriroy6061]

This is awesome!! So glad i found you. If you could speak a little louder, it would be even better. Thanks a ton!

[@sergiocakmak]

thank you Houssem this video help me so much God bless you

[@malaythakershi24]

Hello Houssem, your video tutorials have been a great help. Is complete source code available on github? I appreciate.

[@HoussemDellai]

Thank you Malay for your question. Unfortunately I did not published the source code for this video.

[@malaythakershi24]

Houssem Dellai do you plan to? If not too much trouble, it will be even more helpful. But anyway it is completely up to you. Thanks again.

[@HoussemDellai]

Malay you might find this code interesting github.com/HoussemDellai/CheapIdeas. It is project that looms the same as here.

[@lucapalonca811]

Hi, how can I perform a Navigation.pushAysn() using MVVM pattern?

[@HoussemDellai]

You should use either MVVM Light or Prism (kzbin.info/www/bejne/eoq1fZanfJd1d7s) frameworks :)

[@lucapalonca811]

+Houssem Dellai Thank you for your answer. Another question, which do you prefer? Prism or MVVM light? :)

[@HoussemDellai]

MVVM Light is becoming alittle old and Prism sounds like the new star :)

[@unparadigman]

Why I cant use the Intelillence in Xaml ? Have you got any idea???

[@victoreriksson5412]

You need to install resharper :)

[@unparadigman]

Thanks!

[@BachPhotography]

Every time I get to the Binding section, I get this error: ViewModels:MainViewModel not found in xmlns clr-namespace:XamarinDemoApp.ViewModels;assembly=XamarinDemoApp

[@grzegorzgiera5882]

same problem here, did u solved it?

[@nadirhamidou3811]

you need just to delete "assembly=xxxxxxx"

[@amitsrivastav818]

Hi @Houssem , First of all i thank to you for such kind of amazing video tutorials , i am new in xamarin and in our company mvvm patern is not used at all and we are writing the code in .cs file so can you make a video without using xaml how we can implement mvvm . Please do it .....Thanks

[@obsdark]

What proyect type is that than you are actualy making?, i don't have a MainPage.xaml but a MainActivity.cs instead. I'm new in android, any usefull answer in this would be much apreciated

[@HoussemDellai]

You should choose Xamarin.Forms not Android, when you create new project.

[@usmansheikh9544]

Houssem Dellai in my visual studio 2015 there is no option for Xamarin.Form I have installed xamarin i have choose New Project --> c# -->cross plateform --> but in this menu there is no xamarin from option please help me

[@HoussemDellai]

Usman Sheikh try to restart VS or reinstall xamarin

[@HoussemDellai]

Make sure you select C# -> Cross Platform when creating new project

[@usmansheikh9544]

yeah i am sure

[@superz7940]

hey buddy,i am from china, i like your video,it's so easy to learn from your work----MVVM example. thank you very much! i expect your next video!

[@HoussemDellai]

Thanks for the encouragement :)

[@mandardesai3841]

sir i have general question 1) write code in xaml file or write code in cs file (design and business logic ), which is beneficial and why 2)i choose .cs file because i don't know much about xaml so what is disadvantage Thank you

[@HoussemDellai]

+mandy .netguy it is okay to write UI code into both.xaml and .xaml.cs. But for business code, it is better to write it into your ViewModels.

[@mandardesai3841]

Thank you waiting second part

[@jcevangelista4200]

@Houssem Dellai I copied your code exactly but I wasn't able to make it work. Can i send my code to you?

[@HoussemDellai]

yes, please do :)

[@jcevangelista4200]

What's your email Sir?

[@HoussemDellai]

You can use [e-mail] :)

[@Napstergucio124]

That's because you copied the code instead of learning and understanding. :/

[@moslimdev5616]

excellent جزاك الله خيرا

[@sumitsisodia2220]

How to get intelligence in VS2015 Community and Thanks for clearing my lots of doubt .

[@BaganBatuTV]

@houseem,,, Thanks you very much for all your tutorial...

[@nursyazwaniahmadasri4819]

can you help me?

[@HoussemDellai]

Can you tell the case ?

[@lombertiniabdoul8934]

hi houssem, i really need you. Can you help me in my xamarin forms project please

[@-crossapp9280]

hi thanks for your tutorial. its best. can i have your source code?

[@vivek7473]

Good One...

[@arvindchourasiya4738]

Nice keep it up.

[@hasanen9]

very good

[@neilsukalikar4257]

pLEASE work on audio quality man , you taught very nice but sound quality is very poor. Even in your beginners videos sound is not that great.

[@stanhvdg3727]

Thank you so much :D

[@EnerServDoomer]

Thanks

[@Kendo3065]

Excellence.

[@pablokintopp2]

Thanks!

[@danielcalle9524]

Exellent