我正在使用引导程序设置快照应用程序,但它无法正常工作。 snapshop应用程序独立运行作为原始代码。就是这样:
<button>Take snapshot</button>
<br />
<video autoplay ></video>
<canvas ></canvas>
<script>
var idx = 0;
var filters = ['','grayscale', 'sepia', 'blur', 'brightness', 'contrast', 'hue-rotate',
'opacity', 'drop-shadow', 'saturate', 'invert'];
function changeFilter(e) {
var el = e.target;
el.className = '';
var effect = filters[idx++ % filters.length]; // loop through filters.
if (effect) {
el.classList.add(effect);
}
}
document.querySelector('video').addEventListener('click', changeFilter, false);
document.querySelector('canvas').addEventListener('click', changeFilter, false);
</script>
<!-- img id="hu" src="" -->
<script>
// Put event listeners into place
window.addEventListener("DOMContentLoaded", function() {
var video = document.querySelector('video');
var button = document.querySelector('button');
var canvas = document.querySelector('canvas');
var ctx = canvas.getContext('2d');
var onFail = function(error) {
alert('\t\t\t\t\tSorry. \nIt seems you (or your browser) rejected access. \n\t\tCheck the FAQ for solutions. \nThe error is: ' + error);
console.log('Video Capture Error: ', error.code);
};
// create snapshot function
function snapshot() {
// set the canvas to the dimensions of the video
canvas.width = video.clientWidth;
canvas.height = video.clientHeight;
ctx.drawImage(video, 0, 0);
}
// navigator.getUserMedia = navigator.getUserMedia || navigator.webkitGetUserMedia || navigator.mozGetUserMedia || navigator.msGetUserMedia;
if (navigator.getUserMedia) {
navigator.getUserMedia({video: true}, function(stream) {
video.src = window.URL.createObjectURL(stream);
button.addEventListener('click', snapshot, false);
},onFail);
} else if (navigator.webkitGetUserMedia) {
navigator.webkitGetUserMedia({video: true}, function(stream) {
video.src = window.webkitURL.createObjectURL(stream);
button.addEventListener('click', snapshot, false);
},onFail);
} else if (navigator.mozGetUserMedia) {
navigator.mozGetUserMedia({video: true}, function(stream) {
video.src = window.mozURL.createObjectURL(stream);
button.addEventListener('click', snapshot, false);
},onFail);
} else if (navigator.msGetUserMedia) {
navigator.msGetUserMedia({video: true}, function(stream) {
video.src = window.msURL.createObjectURL(stream);
button.addEventListener('click', snapshot, false);
},onFail);
} else {
// getUserMedia not supported, fallback video information plus alert...
video.src = 'assets/vid/fallback.webm';
video.src = 'assets/vid/fallback.';
video.src = 'assets/vid/fallback.';
}
}, false);
</script>
当我将此默认导航栏添加到“body”正下方的页面顶部时,快照将停止工作:
<div class="row">
<nav class="navbar navbar-default" role="navigation">
<div class="navbar-header">
<button type="button" class="navbar-toggle" data-target=".navbar-ex1-collapse" data-toggle="collapse">
<span class="sr-only">Toggle navigation</span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
</button>
<a class="navbar-brand" href="#">Brand</a>
</div>
<div class="collapse navbar-collapse navbar-ex1-collapse">
<ul class="nav navbar-nav">
<li class="active"><a href="#">Link</a></li>
<li><a href="#">Link</a></li>
<li class="dropdown">
<a href="#" class="dropdown-toggle" data-toggle="dropdown">Dropdown <b class="caret"></b></a>
<ul class="dropdown-menu">
<li><a href="#">Action</a></li>
<li><a href="#">Another action</a></li>
<li><a href="#">Something else here</a></li>
<li><a href="#">Separated link</a></li>
<li><a href="#">One more separated link</a></li>
</ul>
</li>
</ul>
<form class="navbar-form navbar-left" role="search">
<div class="form-group">
<input type="text" class="form-control" placeholder="Search">
</div>
<button type="submit" class="btn btn-default">Submit</button>
</form>
<ul class="nav navbar-nav navbar-right">
<li><a href="#">Link</a></li>
<li class="dropdown">
<a href="#" class="dropdown-toggle" data-toggle="dropdown">Dropdown <b class="caret"></b></a>
<ul class="dropdown-menu">
<li><a href="#">Action</a></li>
<li><a href="#">Another action</a></li>
<li><a href="#">Something else here</a></li>
<li><a href="#">Separated link</a></li>
</ul>
</li>
</ul>
</div>
</nav>
</div>
我发现“canvas”元素丢失或丢失,我的浏览器很难。 我在Debian Linux上使用Chromium(Ubuntu 12.04)。
我只使用了Bootstrap 3和核心依赖项。