[Fixed] Expansion-panel from material angular 4

Issue

I hava an angular 4.4.4 application with material 2.0.0-beta.12 and I want to use the mat-expansion-panel from material design.

This is my code :

           <mat-expansion-panel class="parametersPanel">
                    <mat-expansion-panel-header>
                        <mat-panel-title>
                            PARAMETERS
                        </mat-panel-title>
                    </mat-expansion-panel-header>
                    <table style="width:100%">
                        <tbody>
                            <tr class="parameterListItem">
                                <td class="icon"><img src="assets/images/alert.png"></td>
                                <td class="parameterName">Parameter 1</td>
                                <td class="parameterValue">Value</td>
                                <td class="unit">unit</td>
                            </tr>                        
                        </tbody>
                    </table>
            </mat-expansion-panel>

So it works well but it possible to remove the margin in the mat-expansion-panel-body which has, from the browser margin: 0 24px 16px; ?

Solution

In your style.css or your components style you need to add the following css:

/deep/ .parametersPanel .mat-expansion-panel-body {
    padding: 0;
}

This is due to view encapsulation. You can read more about this here: https://angular.io/guide/component-styles

Update:

The use of /deep/, ::ng-deep to modify the styles of material components has been deprecated. See this link.

However, using @angular/core ^6.1.0 and @angular/material ^6.4.6 I was able to change the style of Angular Material’s Expansion panel without having to add anything specific. It seems like you can now simply change the style in your components css file. So this should work:

.mat-expansion-panel-body {
    padding: 0;
}

You can read here for more information about the deprecation of /deep/, ::ng-deep here.