dharmendra – Best DevOps

[ERROR: flutter/runtime/dart_vm_initializer.cc(41)] Unhandled Exception: type ‘List’ is not a subtype of type ‘FutureOr’

dharmendra — Thu, 07 Sep 2023 07:23:50 +0000

Error

Restarted application in 6,092ms.
I/flutter ( 4152): yaha tak aa raha hai onepices
I/flutter ( 4152): https://www.myhospitalnow.com/doctors/api/v1/doctor-api/j/get-all-doctors
E/flutter ( 4152): [ERROR:flutter/runtime/dart_vm_initializer.cc(41)] Unhandled Exception: type 'List' is not a subtype of type 'FutureOr'
E/flutter ( 4152): #0      _HomePageState.getDoctors
home_page.dart:34
E/flutter ( 4152): 
E/flutter ( 4152):

Solution:

It looks like the error you’re encountering is due to a type mismatch between the return type of your getDoctors function and the expected return type when setting the doctors state. You’re trying to set a list (List) to the doctors state, but the function is declared to return a Future.

To resolve this issue, you should update your getDoctors function to return a List instead of a Future. Here’s the modified code:

Your code ought to function as intended after this modification, which should fix the type mismatch problem. The obtained information is now assigned directly to the doctor’s list within the setState function, and the getDoctors function now returns a FutureVoid.

Form Validation in Flutter

dharmendra — Wed, 06 Sep 2023 05:43:57 +0000

Every application needs to have form validation. There are other ways to validate forms in the flutter application, for as by utilising a TextEditingController. However, managing text controllers for each input can get complicated in large applications. As a result, Form offers us a practical method for verifying user inputs.

Although the condition is applied in each TextFormField with a widget name validator as shown in the example below, the input is validated in your submit function (the method that is executed once the user has provided all of the details).

The Validator widget accepts a function with a single input value as a parameter, and it then checks the condition specified in the Validator function. Use of the key

Example:

Output:

List of Popular Guest Websites and Link Buildings

dharmendra — Tue, 05 Sep 2023 05:37:47 +0000

Link building is still an essential tactic for boosting website visibility and authority in the dynamic world of digital marketing and search engine optimization (SEO). The realm of link building and guest posting, including details on what each term entails, tips for carrying them out successfully, and a directory of well-known websites where you can engage in these activities.

What is Link Building?

A fundamental SEO strategy called link building aims to get other websites to link to yours (or “backlink” them). The concept is straightforward: backlinks from other websites are viewed as endorsements by search engines like Google. It can help your search engine rankings when trustworthy websites link to your content since it tells search engines that your website is reliable and worthwhile.

How to do Link Building?

Create shareable, useful material that is of the highest caliber to draw links naturally. Depending on your niche, this could take the form of blog entries, infographics, videos, or other media.

Reach out to websites or bloggers in your sector who are related to your business and ask them to link to your content if it enhances their articles or resources.

Writing useful articles as guest posters for websites in your niche, with a link to your own website included in the text.

Finding broken links on other websites and offering your material as a replacement is known as “broken link building.”

Social media promotion: Post links to your material on social media sites to make it more visible and attract links from other sources.

Benefits of Link Building

Better Search Engine Rankings: The position of your website in search engine results pages (SERPs) can be improved by high-quality backlinks.

More consumers will find your website through search engines as your rankings rise, resulting in an increase in organic traffic.

Enhanced Authority: Your website’s authority and reputation in your niche are established by high-quality backlinks coming from reliable websites.

Brand Exposure: Link building can make your brand more visible to a larger audience, which can enhance brand recognition.

What is Guest Posting?

Writing and publishing content on other websites as a guest author is known as guest posting or guest blogging. You often get a byline with a link to your website in return for your content. You may establish your authority in your niche and reach out to the hosting website’s audience by blogging as a guest.

Free Guest Posting Websites: https://www.devopsschool.com/blog/top-41-websites-for-free-guest-posting/

Free Quality Backlinks Websites: https://www.devopsschool.com/blog/list-of-popular-free-websites-for-link-building/

Advantages of Guest Posting

Quality Backlinks: Guest posts often come with valuable backlinks to your website, boosting your SEO efforts.
Targeted Traffic: Guest posting on websites in your niche can attract a relevant and engaged audience to your site.
Brand Exposure: Writing for authoritative websites can increase your brand’s visibility and credibility.
Networking: Guest posting helps you connect with influencers and experts in your industry, opening doors for future collaborations.

How Guest Posting is Beneficial

Authority Building: Contributing valuable content to authoritative websites showcases your expertise and establishes you as a thought leader in your field.

Traffic Generation: Guest posts can drive targeted traffic to your website, as readers are likely interested in your niche.

Link Building: The backlinks from guest posts enhance your website’s SEO, contributing to higher search engine rankings.

Networking Opportunities: Guest posting enables you to build relationships with other bloggers and professionals in your industry, which can lead to collaborations and partnerships.

No version of NDK matched the requested version in flutter >> Solved.

dharmendra — Wed, 30 Aug 2023 07:15:54 +0000

I was attempting to link Firebase with my Flutter app using the SHA1 key.
Several projects started failing independently after switching to Android Gradle plugin 3.6.0 (published on February 24, 2020), with the following error:

Version 20.0.5594570 of the NDK was not available. Locally accessible versions are 21.0.6113669.
It’s very easy to “fix” this locally by installing the previous version of the expected ndk:

ndk;20.0.5594570 in the sdkmanager
I want to know, though, where and how this previous version is specified. And how can I upgrade it to the most recent 21.0.6113669 version?

After some research, I discovered the answer.

The machine you are using right now, I’m assuming, has NDK installed, and it was able to create your project before, but it started failing with the

Option 1:

In the Project Structure Dialogue, you can just choose the NDK that is already installed locally.

By selecting File > Project Structure… or by hitting the Windows hotkeys CTRL + ALT + SHIFT + S, you can access the Project Structure Dialogue.

Option 2:

Option 1 will typically work because it will edit your local.properties file for you. But in accordance with this official instructions, you can configure it from your module gradle script if you wish to use a consistent NDK version across all computers you use to build the project. Simply include the ndkVersion in the android section of your module gradle script.

android {
    ndkVersion "major.minor.build"
}

replacing the string between the double quotes with the NDK version you want to use

[SOLVED] Flutter: Cannot run with sound null safety, because the following dependencies don’t support null safety

dharmendra — Tue, 29 Aug 2023 07:02:14 +0000

Problem

I’m using flutter_recaptcha_v2: ^0.1.0. Now, I am trying to run it using flutter run, however, it will not start because of the following error:

Error: Cannot run with sound null safety, because the following dependencies
don't support null safety:

- package:flutter_recaptcha_v2
- package:webview_flutter
- package:http
- package:http_parser

For solutions, see https://dart.dev/go/unsound-null-safety
FAILURE: Build failed with an exception.

* Where:
Script 'C:\src\flutter\packages\flutter_tools\gradle\flutter.gradle' line: 1035

* What went wrong:
Execution failed for task ':app:compileFlutterBuildDebug'.
> Process 'command 'C:\src\flutter\bin\flutter.bat'' finished with non-zero exit value 1

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 21s
Exception: Gradle task assembleDebug failed with exit code 1
Exited (sigterm)

Solution

If you want to run your project with –no-sound-null-safety so now you add this line to your main. dart file in the top(first line) with a comment.

// @dart=2.9

Then run your project.

[SOLVED] Error: “Bottom Overflowed” error caused by the keyboard.

dharmendra — Mon, 28 Aug 2023 06:27:47 +0000

You get the error message “Bottom overflowed by 67 pixels” when the keyboard appears. Technically speaking, the viewport’s size was decreased, which led to an overflow in our layout. Look at the picture below:-

The widgets inside the scaffold might be prevented from resizing when the keyboard opens, although this could result in some widgets being hidden by the keyboard. The Scaffold widget’s resizeToAvoidBottomInset attribute can be used to do this.

The Column widget can also be contained within a scrollable widget. The SingleChildScrollView is an effective built-in widget offered by Flutter. The best way to prevent the “Bottom overflowed” problem when the keyboard opens is to do this.

If it’s not working, take the following actions:-

Android removal method 1In order to prevent the flutter code from being overridden, add resizeToAvoidBottomPadding: false to the scaffold and set windowSoftInputMode=”adjustResize” from the AndroidManifest.xml file as seen below:

Scaffold(
      resizeToAvoidBottomPadding: false,
      appBar: AppBar()
)

Method 2: Just Add Android (Not Recommended)When windowSoftInputMode=”stateVisible” is specified in the activity of the AndroidManifest.xml file, only Android will function and not iOS.

<activity
       ...
        android:windowSoftInputMode="stateVisible">

Note: Don’t set it to android:windowSoftInputMode=”adjustResize”

How to get SHA1-Key in Flutter?

dharmendra — Sun, 27 Aug 2023 06:18:55 +0000

Open Android Studio
Open Project
Reveal android folder
Right click “gradlew” file and select Open in Terminal –

5. Go to the terminal view and paste: gradlew signingReport or ./gradlew signingReport if you’re using PowerShell or a Unix-based system like Windows.

6. Press enter and scroll to “Variant: debug” to get the SHA1 key

How to get SHA1-Key in Android Studio?

dharmendra — Sat, 26 Aug 2023 06:06:18 +0000

Go to the project folder in the terminal.

Mac keytool -list -v -keystore ~/.android/debug.keystore -alias androiddebugkey -storepass android -keypass android

Windows keytool -list -v -keystore "\.android\debug.keystore" -alias androiddebugkey -storepass android -keypass android

Linux keytool -list -v -keystore ~/.android/debug.keystore -alias androiddebugkey -storepass android -keypass android

GUI Android Studio.

Select android/app/build.gradle file and on the right top corner click “Open for Editing in Android Studio”

Open Gradle panel and double click on “SigninReport”,

That’s it! If you use Firebase – add these 2 keys there. You should add both keys, otherwise, without the release key, Google login will not work on the devices.

Flutter, Try correcting the name of an existing method, or defining a method named flat button, raised button

dharmendra — Fri, 25 Aug 2023 11:06:25 +0000

Error:

Try correcting to the name of an existing method, or defining a method named ‘OutlineButton’ in flutter 3.0.0. it isn’t defined for the type

Solution 1:

Yes. That is a breaking change. And it is listed up top in the breaking changes documentation:

The FlatButton, RaisedButton and OutlineButton widgets have been replaced by TextButton, ElevatedButton, and OutlinedButtonrespectively.

source

Flutter – The method ‘forEach’ isn’t defined for the type, The method ‘forEach’ isn’t defined for the type ‘Object’. Try correcting the name to the name of an existing method, or defining a method named ‘forEach’. The method isn’t defined for the type class. 0. Agora local view showing blank screen on Flutter. 0.
Try correcting the name to the name of an existing method, or defining a method named ‘configure’
Question:
I got this error when I try to run flutter app.
The method ‘configure’ isn’t defined for the type ‘FirebaseMessaging’. Try correcting the name to the name of an existing method, or defining a method named ‘configure’.

Solution 2:

That widget have been changed to OutlinedButton .

Old Widget was : OutlineButton
Old Theme was : ButtonTheme
New Widget is : OutlinedButton
New Theme is : OutlinedButtonTheme
Here’s an example :

How to Add Input Section to Mobile App in Flutter using dart packages?

dharmendra — Thu, 24 Aug 2023 10:49:27 +0000

I’ll describe how to add an input section to a mobile app in Flutter in this article. So, for this blog, I’m going to open main.dart in the VS Code editor, create a programme, and import

“package:flutter/material.dart” import

Next, I construct a headline like “Happy Journey” using StatelessWidget, a theme, and the primarySwatch colour blue for the theme. Then, I make a button using RaisedButton and an input area with the aid of InputDecoration decoration, adding a few stylistic classes, and using the variable “myvar” for the shown text. The entire code is listed below:

In is Functionality When you type in input section then show input section word in default value which is assign upper side of Input like that below image.

Error – Dart SDK is not configured in Android Studio.

dharmendra — Wed, 23 Aug 2023 10:31:51 +0000

The Dart SDK is not set up.
First, check to see if your flutter framework SDK path is set whenever you encounter this error. My system does not have it configured. I will now demonstrate how to set up the Flutter SDK path. then your Dart SDK will be configured immediately. You must first install both plugins, such as Flutter and Dart. Let’s look at the steps below.

First, open the File menu.

Step 1 : Go to File Menu
Step 2: Press Ctrl + Alt + S to select Settings.
Step 3: Next, under the Language & Frameworks Tab, select Flutter.
Step 4: I installed Flutter in this directory (C:srcflutter) on my computer.
[Note: Please copy the location of the flutter installed on your PC]
Step 5: Copy the location above and paste it into the directory of your Flutter SDK:

Settings under File Menu

Set Flutter SDK path

Dart SDK path set automatically

After applying above steps your error will be solved. Thanks for reading this article. if you find any other issue in Android Studio then comment us.

References :
https://stackoverflow.com/questions/48650831/dart-sdk-is-not-configured
Click Here (Youtube Video )

[SOLVED] Error: Your app isn’t using AndroidX.

dharmendra — Tue, 22 Aug 2023 10:23:19 +0000

I used Windows’ Visual Studio Code to create a flutter app. When I run the project, a notice appeared saying,

AndroidX is not used by your app.
You may easily migrate your app by following the instructions on https://goo.gl/CP92wY to prevent any build failures.

However, while creating the Android project study and its APK with Flutter, an error occurred. So here is the answer:

Step 1. Go to Android folder of your project.

Step 2. Open gradle.properties File.

Step 3. Paste the Below Code in the file.

android.useAndroidX=true
android.enableJetifier=true

What is the difference between stateless and stateful widgets? >>Flutter.

dharmendra — Mon, 21 Aug 2023 07:31:15 +0000

I hope it will be helpful to you as well. I am learning Dart/Flutter and attempting to comprehend how the Widgets system works.

In reality, there are three types of widgets, not simply two.

Stateful widget
Stateless widget
Inherited widget

Stateful Vs stateless

Stateless Widget

A constant is similar to a stateless widget. It is unchangeable. A stateless widget must be recreated if you want to modify what is displayed by it.

Stateless widgets are in handy when the component of the user interface you are describing depends only on the configuration data contained in the object itself and the BuildContext in which the widget is inflated. Consider utilizing StatefulWidget for compositions that can vary dynamically, such as those that are clock-driven internally or dependent on a system state.

Stateful widgets

A constant is similar to a stateless widget. It is unchangeable. A stateless widget must be recreated if you want to modify what is displayed by it.

Stateless widgets are in handy when the component of the user interface you are describing depends only on the configuration data contained in the object itself and the BuildContext in which the widget is inflated. Consider utilising StatefulWidget for compositions that can vary dynamically, such as those that are clock-driven internally or dependent on a system state.

Every time a StatefulWidget is inflated, the framework runs createState, which means that if the widget has been added into the tree more than once, different State objects may be linked to the same StatefulWidget. The framework will also call createState once again to create a new State object if a StatefulWidget is removed from the tree and then added back in, streamlining the lifecycle of State objects.

Inherited Widget

The Inherited widget combines the best of both worlds. It has no states and is unchangeable. However, a different widget (of any kind) can subscribe to the inherited widget. Therefore, any widgets that have subscribed to your inherited widget will be redrawn when you replace it with a new widget.

A stateful widget will typically serve as a Controller in the end. The View will be a stateless widget. Your configuration file or your model will be the inherited widget.

Stateless widgets are immutable, which means that none of the values in their properties can be changed.

Stateful widgets keep track of variables that may change throughout the course of their existence. A stateful widget must implement at least two classes: 2) a State class, which is an instance of (1) a StatefulWidget class. Although the State class remains during the lifetime of the widget, the StatefulWidget class itself is immutable.

How to add Images in Flutter.

dharmendra — Sun, 20 Aug 2023 13:10:38 +0000

Make an image folder inside an assets folder, and if necessary, generate assets.

Flutter Image_directory

This should be in your root folder, and you can also find a pubspec.yaml file there.

pubspec.yaml

In order to update some lines in this file, open it in your vscode editor and make the necessary modifications.

To this

after this just use your images in your code after including child image function.

Remove HTML tags from a String in Dart

dharmendra — Sat, 19 Aug 2023 07:29:47 +0000

Step 1:

Add the html package to your pubspec.yaml file:

dependencies:
  flutter:
    sdk: flutter
  html: ^0.15.0 # Use the latest version of the html package

Step 2:

Import the necessary package in your Dart file:

import 'package:flutter/material.dart';
import 'package:html/parser.dart'; // Import the HTML parser

// ... (rest of your imports)

Step 3:

Modify the TextSpan widget to parse and display the HTML content:

fatal: will not add file alias ‘Test-Plan/readme.md’ (‘Test-plan/readme.md’ already exists in index)

dharmendra — Fri, 18 Aug 2023 06:01:12 +0000

Error

Solution

Change the capitalization of the “file” name and add “1” to the end (or another symbol) Stage (without commit) = result “File1” – renaming files***
Remove “1” from the end Stage (without commit) = result “File” – renaming files (only capitalization now)
Now Do commit.

After that type this command

$ git config --local core.ignorecase false

How to Create a Login Form In Flutter using Dart packages?

dharmendra — Thu, 17 Aug 2023 05:52:36 +0000

I’ll describe how to develop a login form in flutter using the dart package in this blog. Therefore, I’ll open “lib/main.dart” in an editor before I create a project and import-

importing ‘package:flutter/material.dart’

Use a stateless widget after that for the title and colour. the use of stateful widgets for complete functionality and design after that. With the aid of InputDecoration, I am using a background image in this application to create a card within a container. I’m making two parts for input. Similarly, Username & Password, and make a button that reads “Login.” Here is a code mention.

[SOLVED] Flutter: Cannot run with sound null safety, because the following dependencies don’t support null safety

dharmendra — Wed, 16 Aug 2023 05:43:39 +0000

Problem

Flutter_recaptcha_v2: 0.1.0 is what I’m using.I am currently attempting to execute it using flutter run, but it is failing with the following error:

Error: Cannot run with sound null safety, because the following dependencies
don't support null safety:

- package:flutter_recaptcha_v2
- package:webview_flutter
- package:http
- package:http_parser

For solutions, see https://dart.dev/go/unsound-null-safety
FAILURE: Build failed with an exception.

* Where:
Script 'C:\src\flutter\packages\flutter_tools\gradle\flutter.gradle' line: 1035

* What went wrong:
Execution failed for task ':app:compileFlutterBuildDebug'.
> Process 'command 'C:\src\flutter\bin\flutter.bat'' finished with non-zero exit value 1

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 21s
Exception: Gradle task assembleDebug failed with exit code 1
Exited (sigterm)

Solution

You need now add this line to your main if you want to run your project with the –no-sound-null-safety option.First line of the dart file is a comment.

// @dart=2.9

then run your project.

[SOLVED] Flutter : NoSuchMethodError: The getter ‘isEmpty’ was called on null.

dharmendra — Tue, 15 Aug 2023 05:35:24 +0000

Problem

When I call an API, the response comes back as Variable Data ($data). When data arrives, there is no error; but, when I receive null as a response, I receive the error Unhandled. Exception: The getter ‘isEmpty’ was called on null, resulting in a NoSuchMethodError.

The code below is giving me an error when I use it:

Solution

Due to the fact that $data returns null, I’ve used

If (data?.isEmpty?? true), then

? avoids an error if the expression’s first component is null, and?? Since isEmpty and == null are treated equally for the purposes of the if(…) check, true results in true if the previous component of the expression is null.

My code is now correctly running.

[Solved] Flutter : [core/not-initialized] Firebase has not been correctly initialized. Have you added the “google-services.json” file to the project?

dharmendra — Mon, 14 Aug 2023 05:26:40 +0000

Problem

I’ve connected my Flutter app to Firebase by adding the SHA1 key ( How to Get SHA-1 key in Android Studio for Firebase. ) and package name in the Firebase console, and also downloaded and provided google-service.json in my Flutter app at android/app. But when I run the app it’s Showing an error that I’ve not provided google-service.json a file in my app. The Error Says –

E/flutter (15568): [ERROR:flutter/lib/ui/ui_dart_state.cc(166)] Unhandled Exception: [core/not-initialized] Firebase has not been correctly initialized. Have you added the "google-services.json" file to the project? 
E/flutter (15568):

Solution

After hours of struggle, I am able to figure out the solution.

First, add the ‘google-services.json‘ plugin as a dependency inside of the Android/build.gradle file:

2. Lastly, execute the plugin by adding the following underneath the line apply plugin:
add after ‘com.android.application’, within the /android/app/build.gradle file:

apply plugin: ‘com.google.gms.google-services

dharmendra – Best DevOps

[ERROR: flutter/runtime/dart_vm_initializer.cc(41)] Unhandled Exception: type ‘List’ is not a subtype of type ‘FutureOr’

Error

Solution:

Form Validation in Flutter

Example:

Output:

List of Popular Guest Websites and Link Buildings

What is Link Building?

How to do Link Building?

Benefits of Link Building

Top Free Websites for Link Building

What is Guest Posting?

Advantages of Guest Posting

How Guest Posting is Beneficial

Top Websites for Free Guest Posting & Quality Backlinks

No version of NDK matched the requested version in flutter >> Solved.

Option 1:

Option 2:

[SOLVED] Flutter: Cannot run with sound null safety, because the following dependencies don’t support null safety

Problem

Solution

[SOLVED] Error: “Bottom Overflowed” error caused by the keyboard.

How to get SHA1-Key in Flutter?

How to get SHA1-Key in Android Studio?

Flutter, Try correcting the name of an existing method, or defining a method named flat button, raised button

Error:

Try correcting to the name of an existing method, or defining a method named ‘OutlineButton’ in flutter 3.0.0. it isn’t defined for the type

How to Add Input Section to Mobile App in Flutter using dart packages?

Error – Dart SDK is not configured in Android Studio.

[SOLVED] Error: Your app isn’t using AndroidX.

What is the difference between stateless and stateful widgets? >>Flutter.

I hope it will be helpful to you as well. I am learning Dart/Flutter and attempting to comprehend how the Widgets system works.

In reality, there are three types of widgets, not simply two.

Stateless Widget

Stateful widgets

Inherited Widget

How to add Images in Flutter.

Remove HTML tags from a String in Dart

Step 1:

Step 2:

Step 3:

fatal: will not add file alias ‘Test-Plan/readme.md’ (‘Test-plan/readme.md’ already exists in index)

Error

Solution

How to Create a Login Form In Flutter using Dart packages?

[SOLVED] Flutter: Cannot run with sound null safety, because the following dependencies don’t support null safety

Problem

Solution

[SOLVED] Flutter : NoSuchMethodError: The getter ‘isEmpty’ was called on null.

Problem

Solution

[Solved] Flutter : [core/not-initialized] Firebase has not been correctly initialized. Have you added the “google-services.json” file to the project?

Problem

Solution