set box decoration color based on dark / light theme-CodePudding

I am designing a container in flutter, based on the theme, it can be dark or light, I want to change the background color of container.

I did some researched and didn't found any ways, so my question is

Is it even possible to do? If yes, then how?

I am new to Flutter, so if it's basic question, please don't mind.

Here is my code

Container(
  padding: const EdgeInsets.all(kDefaultPadding),
  //change required here
  decoration: const BoxDecoration(color: kDarkColor),
  child: Column(
  // ...
  ))

CodePudding user response：

In your root file (main.dart) your entry point of the app is located. In general, you have a class MyApp which returns a MaterialApp widget. This out-of-the-box widget from the Flutter SDK lets you define your app´s theme. Here you can define the theme.

In your Container, you can assign the color directly via the color parameter. To refer to your theme data do this: Theme.of(context).backgroundColor for example.

CodePudding user response：

You can use platformBrightness from MediaQuery.

final isDarkTheme = MediaQuery.of(context).platformBrightness == Brightness.dark;

  Container(
    padding: const EdgeInsets.all(kDefaultPadding),
    //change required here
    decoration: const BoxDecoration(color: isDarkTheme? kDarkColor: kLightColor),
    child: Column(
    // ...
  ),

Also see how to implement dark mode in flutter

CodePudding user response：

We can achieve this by reading the color from ThemeData.

Setting Themes

// light Theme
ThemeData lightThemeData(BuildContext context) {
  return ThemeData.light().copyWith(
    backgroundColor: Colors.grey.shade100,
  );
}

// dark Theme
ThemeData darkThemeData(BuildContext context) {
  return ThemeData.dark().copyWith(
    backgroundColor: Colors.grey.shade900,
  );
}

Configuring Theme in MaterialApp

      theme: lightThemeData(context),
      darkTheme: darkThemeData(context),

Finally using it

BoxDecoration(color: Theme.of(context).backgroundColor),