I am using the server-side of Blazor.
I want to change the CSS of the body.
In Jquery I can write the code like this easily:
$("body").css("overflow-y","hidden");
However, with this tutorial(Blazor Change Validation default css class names) said, it seems I can only change the CSS by changing the class name.
It is so complex while crossing the component, especially the body is at the top of all the components.
I wonder whether there is a way can changes CSS directly in Blazor. Thank you.
There are several ways of getting out of the "blazor way" of doing things and accomplishing css modification of an element.
Simplest: Just like you can use the class attribute, use the style attribute
<element style=@myStyle></element>
@code {
string myStyle;
void MyMethod() {
myStyle="overflow-y: hidden;"
}
}
Advanced: Use JS interop
a. In the main view (index.html or Pages/_Host.cshtml depending on project type), create a js endpoint for your component
<script>
window.applyStyleForElement = function(styleOp) {
document.getElementById(styleOp.id).style[styleOp.attrib] = styleOp.value;
}
</script>
b. In razor file:
@Inject IJRRuntime JSRuntime
<element id=@myId></element>
@code {
string myId = Guid.NewGuid().ToString("n");
async Task MyMethod() {
await JSRuntime.InvokeAsync("applyStyleForElement",
new { id = myId, attrib = "overflowY", value = "hidden" });
}
}
Finally, applying to your special case with body element ("advanced" method above).
a. In the main view (index.html or Pages/_Host.cshtml depending on project type), create a js endpoint
<script>
window.applyStyleForBody = function(style) {
document.body.style[style.attrib] = style.value;
}
</script>
b. In razor file:
@Inject IJRRuntime JSRuntime
(...)
@code {
async Task MyMethod() {
await JSRuntime.InvokeAsync("applyStyleForBody",
new { attrib = "overflowY", value = "hidden" });
}
}
Well, Blazor does not support direct css modification yet, since Web Assembly doesn't. Anyway heads up, it is on the road-map for Web Assembly/Blazor.
Therefor your best bet is, changing the class name with variables. At least for now.
Well, actually there is a way to do that and it works really good (it might suffer a little delay though). I know this answer is a little bit late but it might help other people who face the same challenge.
We need to create some JS code that includes the wanted files:
function includeLeftStyle() {
appendStyle("left.css");
}
function includeRightStyle() {
appendStyle("right.css");
}
function appendStyle(path) {
var element = document.createElement("link");
element.setAttribute("rel", "stylesheet");
element.setAttribute("type", "text/css");
element.setAttribute("href", path);
document.getElementsByTagName("head")[0].appendChild(element);
}
The wished CSS can be called according to the language (any other coditions) in the MainLayout:
protected override async Task OnAfterRenderAsync(bool firstRender)
{
if (firstRender)
{
if (// is left)
{
await JSRuntime.InvokeAsync<object>("includeLeftStyle");
}
else
{
await JSRuntime.InvokeAsync<object>("includeRightStyle");
}
}
}
Happy coding! :)
I'M NOT SURE IT'S THE RECOMMENDED WAY BUT it works!
For one of my project, I include a in the page html itself, using params :
<style>
html
{
background-color:@_ColorCss;
}
</style>
//html stuff here
@code
{
public string Color{ get; set; } = "white";
string _ColorCss => $"{Color}"; //use this in case of formatting (ex : add 'px' or that kind of things)
//code stuff here
}
not the very sexiest way but it works
have fun !
Beginnig from the @Tewr answer, we can also change the whole class:
a) In the main view (index.html or Pages/_Host.cshtml depending on project type), create a js endpoint
<script>
window.applyStyleForElement = function (styleOp) {
if (styleOp != null) {
document.getElementById(styleOp.id).className = styleOp.value;
}
}
</script>
b) Then in the razor file
async Task MyMethod(string sortColumn)
{
await JsRuntime.InvokeVoidAsync("applyStyleForElement",
new { id = sortColumn, value = "newClassName" });
}