When developing app with flutter, i want to define some common styles.
The code is as follows:
import 'package:flutter/material.dart';
class AppStyle {
static Color colorRed = const Color(0xffe04f5f);
static Color colorWhite = const Color(0xffffffff);
static Color colorGreen = const Color(0xff1abc9c);
}
Now, i want to define a new style.
static TextStyle listRowTitle = const TextStyle(fontSize: 20.0, color: colorGreen);
If you write to the above, then colorGreen will have a problem here. The wrong message is
[dart] Invalid constant value.
[dart] Arguments of a constant creation must be constant expressions.
Color colorGreen
If you change colorGreen to Color (0xff1abc9c), there is no problem!
static TextStyle listRowTitle = const TextStyle(fontSize: 20.0, color: Color(0xff1abc9c));
Ask me to teach meļ¼please!
Since, colors are defined in a class you have to do something like below:
AppStyle.colorGreen
Udate:
Ohh, I see, you are using cont TextStyle
. So, you can remove const
or add const
for your AppStyle
.
I simply removed the const
from TextStyle
:
TextStyle(fontSize: 20.0, color: AppStyle.colorGreen)
The problem is you are declaring a variable value (colorGreen) to a property (color) of a constant widget. Constant widgets cannot vary, change.
Just remove the modifier const from your widget
static TextStyle listRowTitle = const TextStyle(fontSize: 20.0, color: colorGreen);
User contributions licensed under CC BY-SA 3.0