When to Use Keys - Flutter Widgets 101 Ep. 4

In this episode, you will learn about key parameters on widgets: when you need keys, where to put keys in your widget tree, and which key is right for you. More specifically, you'll learn about he nuances of how keys work, discern when to use keys in your widget hierarchy, and identify the appropriate types of keys to optimize your widget-based structures.

Chapters:
0:00 - Intro
0:39 - When to use keys
2:20 - How keys work
5:13 - Where to put keys
6:53 - Types of Keys

[EmanueleTozzato]

Of all the videos in the series, I feel like I've started with the most complicated! :)

[pradeep]

Now we Most advanced and productive video in this

[lucasyoung]

Angela just sent me here through her flutter bootcamp course. And seriously the Flutter team ROCKS!! Very clear, fun and helpful! Thanks Flutter Team and Emily for this video!

[KaranChecker]

I to be honest didnt catch the usage entirely. The concept of the various keys .. yes, but not the usage.

A slower more hands-on tutorial video would surely help.

[RinaldiMeteoric]

I'm really happy about choosing Flutter to develop my app. It has been 3 weeks since I've started learning flutter and videos like this really clarify and take out the struggle of understanding documentations. Thank you very much Flutter team.

[subtex]

Excellent video. Really appreciate some more in-depth videos like this, while still being short enough to not be an major investment in time to watch it.

[danvilela]

Finally i could understand this! Thanks for the video, very educational!

[danvilela]

Every time i watch this i learn a little bit more. Thanks Emily!

[jatingoyal]

This is the best explanation any student could have asked for, literally the best teaching video and analogy for me in my entire life, thanks a lot Emily

[dkq]

This will be really really helpful!!
I wrote a code for this implemention before but it was really complex to change or even maintain.

[greatestuff]

That was super helpful! I really appreciate the detailed explanation of value, global, object, unique keys. I also appreciate the comment about not using random numbers ..it really shows that they are helping people avoid common stumbling blocks. Thanks Flutter Team! Keep up great work! Love these videos. She makes a comment about the BLOC pattern at the end, I would love to see a dedicated video or series of these types of preplanned and well-polished videos on that pattern.

[noahderebe]

The most clear explanation of Keys currently online!!!!

[sanketsahasrabudhe]

Emily Fortuna can teach instructors all over the world on how to make a video a thousand times more interesting! Great job Flutter Team! Keep more videos coming❤️

[parosk]

honestly the best video that explain key in flutter !

[NextGenerationEdit]

More in depth tutorials like that! Great video!

[nosmirck]

I'm not sure if I'm 100% correct, but another useful use of keys (that I've encountered) is finding specific Widgets during Widget Tests and UI Tests. Let's say you're loading the current temperature, you want to know if it rendered, you don't care about the actual reading but that the actual widget holding the value is rendered. In this case, Keys are very useful (unless I'm doing it wrong and there's another way to identify Widgets during Widgets and Integration Tests)

[yamsani]

This video has actually helped me to fix one of the issue I have in my application because of not properly managing the widget keys.

[joaopedromartins]

That's exactly what I nedded! Thank you guys!

[AshutoshATS]

Btw, her way of explanation is just awesome. She's great with her style and ways of speaking.

[CarlitosVJ]

Hi Emily! Thanks for sharing in such an understandable way!