asp.net video上放canvas如何讓video可以按暫停、開始、全螢幕
时间: 2023-07-27 16:25:51 浏览: 33
要在ASP.NET视频上放置canvas并让视频可以暂停、开始、全屏,你需要使用HTML5的video和canvas元素,并结合使用JavaScript来实现。以下是一些示例代码:
1. 首先,你需要在HTML中添加video和canvas元素:
```
<video id="myVideo" src="video.mp4"></video>
<canvas id="myCanvas"></canvas>
```
2. 然后,你需要在JavaScript中获取video和canvas元素,并为它们添加事件监听器:
```
var video = document.getElementById("myVideo");
var canvas = document.getElementById("myCanvas");
var ctx = canvas.getContext("2d");
video.addEventListener("play", function() {
// 在视频播放时,将canvas绘制到视频上
drawCanvas();
});
video.addEventListener("pause", function() {
// 在视频暂停时,停止canvas绘制
cancelAnimationFrame(requestId);
});
video.addEventListener("ended", function() {
// 在视频结束时,停止canvas绘制
cancelAnimationFrame(requestId);
});
canvas.addEventListener("click", function() {
// 在canvas上点击时,切换视频的播放状态
if (video.paused) {
video.play();
} else {
video.pause();
}
});
```
3. 接下来,你需要编写一个函数来绘制canvas:
```
var requestId;
function drawCanvas() {
// 每帧都清除canvas并重新绘制视频帧
ctx.clearRect(0, 0, canvas.width, canvas.height);
ctx.drawImage(video, 0, 0, canvas.width, canvas.height);
requestId = requestAnimationFrame(drawCanvas);
}
```
4. 最后,你需要为视频添加全屏按钮,当点击该按钮时,将视频全屏:
```
<button onclick="toggleFullScreen()">全屏</button>
function toggleFullScreen() {
if (!document.fullscreenElement && !document.mozFullScreenElement && !document.webkitFullscreenElement && !document.msFullscreenElement ) {
if (video.requestFullscreen) {
video.requestFullscreen();
} else if (video.msRequestFullscreen) {
video.msRequestFullscreen();
} else if (video.mozRequestFullScreen) {
video.mozRequestFullScreen();
} else if (video.webkitRequestFullscreen) {
video.webkitRequestFullscreen(Element.ALLOW_KEYBOARD_INPUT);
}
} else {
if (document.exitFullscreen) {
document.exitFullscreen();
} else if (document.msExitFullscreen) {
document.msExitFullscreen();
} else if (document.mozCancelFullScreen) {
document.mozCancelFullScreen();
} else if (document.webkitExitFullscreen) {
document.webkitExitFullscreen();
}
}
}
```
这样,当你点击全屏按钮时,视频将全屏,并且你可以在canvas上暂停、播放视频。