The problem “Error: The method ‘FlatButton’ isn’t defined for the class ‘PlatformButton'” is seen when you are working on iOS or Flutter and you are trying to use the ‘flatButton’ method in your application.
Given below is the snippet of the problem “Error: The method ‘FlatButton’ isn’t defined for the class ‘PlatformButton'”:
Error: The method 'FlatButton' isn't defined for the class 'PlatformButton'Error: The method ‘FlatButton’ isn’t defined for the class ‘PlatformButton’ is seen because you are using an outdated version of flutter and trying to use the ‘flatbutton’ method which has been deprecated in the latest version of flutter as the ‘textbutton’ is used in the latest version of flutter.
To fix the problem “Error: The method ‘FlatButton’ isn’t defined for the class ‘PlatformButton'”, use the text button method in the latest version of flutter as the ‘flatbutton’ method has been deprecated in the latest version of flutter.
You will also have to make sure that you are using the latest version of flutter in your applications to avoid any other errors.
Steps to Fix the problem “Error: The method ‘FlatButton’ isn’t defined for the class ‘PlatformButton'”:
The first step to fix the problem is that, you will have to use the text button method in the latest version of flutter as the flatbutton method has been deprecated in the latest version of flutter.
You will also have to make sure that you are using the latest verison of flutter in your applications to avoid any other errors
You can also use an elevated button as an alternative solution to using flatbuttons, You can also follow the link mentioned here, to know how to use elevated and textbuttons in place of flatbuttons in your project file.
This should help you fix and understand the problem, “Error: The method ‘FlatButton’ isn’t defined for the class ‘PlatformButton'”.
Conclusion
To address the issue In the most recent version of flutter, the flatbutton method has been deprecated, thus you will need to use the text button method if you see the error message “Error: The method ‘FlatButton’ isn’t defined for the class ‘PlatformButton'”.
To prevent any more issues, you must also ensure that your apps are utilising the most recent version of flutter. You can also use the elevated button in place of ‘FlatButton’.