You have encountered an issue with the mat-form-field because it is being used without a form field control. To resolve this, simply add a form field control such as an <input> element with the matInput directive:
<mat-form-field>
<input matInput placeholder="Input">
</mat-form-field>
Don't forget to import the necessary module in your app.module.ts file:
import { MatInputModule } from '@angular/material/input';
...
imports: [
...
MatInputModule
]
If you are having trouble identifying the source of the issue or how to resolve it, consider explaining your process once you find a solution.
When I faced this issue, I turned to Stackblitz and uncommented a line to reveal the error message telling me to include a MatFormFieldControl within mat-form-field. As I delved into Angular Material Components for the first time, I inspected styles using Devtools but found nothing amiss. Only after checking the console did I discover:
Error: mat-form-field must contain a MatFormFieldControl.
This prompted me to look at the documentation, where I learned about the requirement for a form control within mat-form-field:
The error occurs when a form field control is missing. If using a native <input> or <textarea>, ensure that the matInput directive is added and MatInputModule is imported.
Note: Additionally, a warning about a missing Angular Material core theme may appear in the console, indicating the need to add a theme for proper functionality. More details can be found in the theming guide: https://material.angular.io/guide/theming