滚动更改Java滚动条不透明度的Javascript使我的Nav内容消失

Question

I've looked everywhere but I can't find an answer that applies to this problem.

I have a sticky nav bar that becomes opaque upon scrolling, using this code:

    var target = $('#navbar-container');
var targetHeight = target.outerHeight();

$(document).scroll(function(e){
    var scrollPercent = (targetHeight - window.scrollY) / targetHeight;
    if(scrollPercent >= 0){
        target.css('opacity', 1);
    }
    else  target.css('opacity', 0.50);
});

But this code makes the background, and everything within the nav bar opaque, and I want the text links, and a logo to remain visible. I've read about using an RGB background to make only the background opaque, but I'm unsure how to do this within this code's parameters. I'm sure there's a simple solution, but I can't find it!

Answer 1

Use the background-color attribute instead of opacity.

target.css('background-color', 'rgba(0, 0, 0, 0.5)');

rgba(red, green, blue, alpha)

Answer 2

This is because the parent container will affect any children when using opacity.

Use rgba .

CSS

#navbar-container {
    background-color: rgba(255, 255, 255, 1);
}

JS

var target = $('#navbar-container');
var targetHeight = target.outerHeight();

$(document).scroll(function(e){
    var scrollPercent = (targetHeight - window.scrollY) / targetHeight;
    if(scrollPercent >= 0){
        target.css('background-color', 'rgba(255, 255, 255, 1)');
    }
    else  target.css('background-color', 'rgba(255, 255, 255, 0.5)');
});