Unable to modify some internal styles of Material UI's <Dialog> component - css

Question

I'm trying to apply some reasonably simple styles to my <Dialog> component. In this case, I am trying to round the corners with a border radius. Here are some simple inline styles that I'd like to use to override the default <Dialog> styles:
let overrideStyles = {
padding: 0,
margin: 0,
borderRadiusTopLeft: '4px',
borderRadiusTopRight: '4px',
};
<Dialog> provides a wide variety of possibilities for overriding internal styles. These include bodyStyle, contentStyle, style, titleStyle, overlayStyle, and actionsContainerStyle. I decided to try to apply these styles to each one.
<Dialog
bodyStyle={overrideStyles}
contentStyle={overrideStyles}
style={overrideStyles}
titleStyle={overrideStyles}
overlayStyle={overrideStyles}
actionsContainerStyle={overrideStyles}
modal={overrideStyles}
>
<TestPanel/>
</Dialog>
When I render my TestPanel, it ends up looking like this:
Notice the corners, where my border radius has not been applied... I opened up the inspector and noticed the following div:
If I apply the border radius styling to the highlighted div, the dialog will have its corners rounded as expected. Which leads me to my question...
How do I override the styles of Material UI's <Dialog> component to apply rounded corners as my CSS is attempting?

Answer 1

I solved it with paperProps property.
<Dialog PaperProps={{
style: { borderRadius: 2 } }}
> .... </Dialog>
This perfeclty worked for me

Answer 2

You can override styles like below.
const styles = {
root: { }
paper: { borderRadius: 15 }
}
// ...
<Dialog classes={{
root: classes.root,
paper: classes.paper
}}>
</Dialog>

Answer 3

Unfortunately, Material UI isn't supremely style-friendly. In this case, there's no prop you can override to change the border-radius, so we've got to apply our own class:
let headerStyles = {
color: 'white',
textAlign: 'center',
fontSize: 24,
backgroundColor: '#3B8DBC',
padding: 20,
borderTopLeftRadius: 4,
borderTopRightRadius: 4
};
let bodyStyles = {
backgroundColor: 'white',
padding: 10,
height: 200
};
<Dialog className='test'>
<div style={headerStyles}>Testing</div>
<div style={bodyStyles}>5:43pm</div>
</Dialog>
Then style that class, and, yes, the border-radius has to be set on both of the below CSS classes as well as the TestPanel header:
/* Some rules use !important because Material UI sets them by default */
.test > div > div {
background-color: #3B8DBC; /* Same background-color as TestPanel */
border-top-left-radius: 4px;
border-top-right-radius: 4px;
}
.test > div > div > div {
/* Not overriding the color and border radius here too result in your changes
not being visible. */
background-color: inherit !important;
border-top-left-radius: 4px !important;
border-top-right-radius: 4px !important;
}
.test > div > div > div > div {
/* This div is the topmost padding between the modal content and the edge
of the modal */
padding: 0 !important;
}
This ends up looking like what you want:
screenshot here
Hope this helps!

Answer 4

You can override <Dialog /> styles globally in your application when creating your theme object. The paper key of MuiDialog will let you target the border-radius.
const theme = createMuiTheme({
overrides: {
MuiDialog: {
paper: {
borderTopLeftRadius: '4px',
borderTopRightRadius: '4px'
}
}
}
})
Dialog - CSS api
Material UI Theming

Answer 5

The first answer is not working for me. I tried this and it work perfect for me:
sx={{
"& .MuiDialog-container": {
"& .MuiPaper-root": {
width: "100%",
maxWidth: "740px",
borderRadius: "8px"
}
},
}}