如何淡入 - 淡出隨機位置和隨機大小的三個圖像？

Question

我想放置一個隨機大小和隨機位置隨機淡入/淡出的 div。

我可以用淡入/淡出隨機顯示三個圖像，但我不能將它們隨機放置在隨機大小的地方。

http://jsfiddle.net/qq68m/139/

查詢：

jQuery(function(){
    function random(n) {
        return Math.floor(Math.random() * n);
    }
    var transition_time = 2500;
    var waiting_time = 100;
    var images = $('div#block img');
    var n = images.length;
    var current = random(n);
    images.hide();
    images.eq(current).show();

    var interval_id = setInterval(function () {
        images.eq(current).fadeOut(transition_time, function () {
            current = random(n);
            images.eq(current).fadeIn(transition_time);
        });
    }, 2 * transition_time + waiting_time);
})

html：

<div id="block">
    <img src="http://mobler.com.tr/wp-content/uploads/2017/07/rand1.png">
    <img src="http://mobler.com.tr/wp-content/uploads/2017/07/rand2.png">
        <img src="http://mobler.com.tr/wp-content/uploads/2017/07/rand3.png">

</div>

Answer 1

這是我的解決方案。 它允許您指定圖像比例大小的范圍，並確保無論比例如何，隨機選擇的位置都不會裁剪到容器之外。 我希望這符合您的要求。

編輯：我已經更新了代碼，以便非四邊形圖像現在也將保持它們的比例（如 Phil Murray 示例所示）。

如果通過 css 高度/寬度設置大小對您不起作用，也許使用 CSS3 scaleX/scaleY 屬性可能會給您更平滑的圖像縮放結果。

如果您有任何其他問題，請在此帖子評論中提問。

 jQuery(function(){ function random(n) { return Math.floor(Math.random() * n); } var transition_time = 200; var waiting_time = 100; var images = $('div#block img'); var n = images.length; var current = random(n); images.hide(); images.eq(current).show(); //get the size of the container var boxHeight = document.getElementById('block').offsetHeight; var boxWidth = document.getElementById('block').offsetWidth; //range of possible image scales var objectMaxHeight = 60; var objectMinHeight = 20; var interval_id = setInterval(function () { images.eq(current).fadeOut(transition_time, function () { current = random(n); //gets reference to selected image var $domImage = images.eq(current); //generates random heights and widths for the image to be shown in var generatedHeight = Math.floor( Math.random() * (objectMaxHeight - objectMinHeight) ) + objectMinHeight; // assigns values to the image $domImage.css('height', generatedHeight); $domImage.css('width', "auto"); var imageAutoWidth = $domImage.width(); var generatedYLocation = Math.floor( Math.random() * (boxHeight - generatedHeight + 1) ) + 0; var generatedXLocation = Math.floor( Math.random() * (boxWidth - imageAutoWidth) ) + 0; $domImage.css('top', generatedYLocation); $domImage.css('left', generatedXLocation); $domImage.fadeIn(transition_time); }); }, 2 * transition_time + waiting_time); })

 #block { position: fixed; width: 300px; height: 300px; border: 1px solid red; background: yellow; overflow: hidden; } img { position:relative; top: 0; left: 0; height: 100px; width: 100px; }

 <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <div id="block"> <img src="http://mobler.com.tr/wp-content/uploads/2017/07/rand1.png"> <img src="http://mobler.com.tr/wp-content/uploads/2017/07/rand2.png"> <img src="http://mobler.com.tr/wp-content/uploads/2017/07/rand3.png"> <img src="https://www.fillmurray.com/g/200/500"> <img src="https://www.fillmurray.com/g/500/200"> </div>