13👍
finally i’v fixed this problem, only by adding
providers:[ThemeService] in the app.modules.
i think this problem happens only on these version on angular 8 and ng2-chart 2.4.2
- [Chartjs]-ChartJS with AngularJS – Canvas won't display anything
- [Chartjs]-Chartjs show dot point on hover over line chart
Source:stackexchange.com