• This is Part #2 of the Flutter FAQs series. In this series, I'm compiling all of the frequently asked questions that Flutter developers encounter while building an app.
• So let's get this party started.

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1. How to Auto-Complete TextField

• Filling out a form in an application is really tedious. We don't want to retype the same information in the form every time, such as Name, Email, Address, Phone Number, and so on.
• So, as developers, we can auto-suggest the user when they are on a specific text field.
• To accomplish this, simply supply an array of AutofillHints into the TextField widget's autofillHints attribute.

• TextField(
    ....,
    decoration: InputDecoration(hintText: "Username")
    autofillHints: [AutofillHints.name] // or AutofillHints.email, AutofillHints.postalAddress...
  )
  

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2. How to Refresh/Update AlertDialog

• If you've ever tried to update the state of dialogue by clicking a button within it, you'll notice that the state doesn't update. It's because when you call setState, the parent widget's build is updated. However, in our case, we opened a separate dialogue that is unrelated to the build approach. That is why it is not being updated.
• To update the dialogue, enclose your AlertDialog within the StatefulBuilder widget.
• You will gain access to the setState method, which will be used to update the state of the dialogue.
• Use StatefulBuilder to use setState within Dialog and just update Widgets within it.

• showDialog(
     context: context,
     builder: (context) {
       return StatefulBuilder(
            builder: (context, setState) {
                 return AlertDialog(
                      .......
                 );
            },
       );
    },
  );
  

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3. How to call async function inside initState

• Often, when the screen first loads, we want to call a function. And we call it in initState because it is only called once when the screen loads. This is sufficient for a standard solution. However, if you execute an async function within it, initState will throw an error.
• To resolve this issue, just build your async function outside of initState and call it inside initState as seen below:

• @override
  void initState() {
    super.initState();
    loadDataFromAPI();
  }
  Future<void> loadDataFromAPI() async {    // ....  }
  

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4. How to preload Image

• Sometimes, we'd like to preload certain photos before the screen load. On the first page, for example, we want a background image.
• However, retrieving that image from assets or the internet will take some time before it loads. Because the image only flashes/blinks after image fetch, this could be a negative user experience.
• You can use the precacheImage method in the initState to begin loading an image before your page is constructed.

• @override
  void initState() {
    precacheImage(new AssetImage('...')); // or NetworkImage('...'), etc.
    super.initState();
  }
  

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5. How to hide StatusBar

• By default, the Status bar is visible as shown in the below image:
• 
• If you want to hide it for some reason then simply paste the below code in the main method.

• import 'package:flutter/services.dart';
  void main(){
    SystemChrome.setEnabledSystemUIMode(SystemUiMode.immersive);
    //....
  }
  

• 

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Wrapping Up

• I hope you found this article to be beneficial. If you have any questions related to Flutter, please leave them in the comments. I will try my best to answer it.
• Thank you for spending time reading this article. See you in the next article. So, until then...
•