使用 setInterval 和 JavaScript
Using setInterval and JavaScript
我正在使用 Notification API,但我无法使其与 SetInterval() 一起使用,有人可以指出我做错了什么。只要我点击事件,通知只显示一次。这是我的代码:
document.addEventListener('DOMContentLoaded', function() {
document.getElementById('notifyBtn').addEventListener('click', function() {
if (!('Notification' in window)) {
alert('Web Notification is not supported');
return;
} else {
setInterval(Notification.requestPermission(function(permission) {
var notification = new Notification("Hi there!", {
body: 'I am here to talk about HTML5 Web Notification API',
icon: 'icon.png',
dir: 'auto'
});
setTimeout(function() {
notification.close();
}, 2000);
}),5000);
}
;
});
});
我卡在这里了,请稍等。
您需要将有效的回调传递给 setInterval()
。相反,您传递的是某种方法的 result。试试这个:
setInterval(function () {
Notification.requestPermission(function(permission) {
var notification = new Notification("Hi there!", {
body: 'I am here to talk about HTML5 Web Notification API',
icon: 'icon.png',
dir: 'auto'
});
setTimeout(notification.close, 2000);
})}, 5000);
奖励:看看我是如何简化你的 setTimeout
回调的,只传递 notification.close
方法本身,而不是在匿名函数中调用它。干净多了。
用匿名函数包装你的方法
document.addEventListener('DOMContentLoaded', function() {
document.getElementById('notifyBtn').addEventListener('click', function() {
if (!('Notification' in window)) {
alert('Web Notification is not supported');
return;
} else {
setInterval(function(){Notification.requestPermission(function(permission) {
var notification = new Notification("Hi there!", {
body: 'I am here to talk about HTML5 Web Notification API',
icon: 'icon.png',
dir: 'auto'
});
setTimeout(function() {
notification.close();
}, 2000);
})},5000);
}
;
});
});
我发现了这样的东西:
document.addEventListener('DOMContentLoaded', function() {
document.getElementById('notifyBtn').addEventListener('click', function() {
if (!('Notification' in window)) {
alert('Web Notification is not supported');
return;
} else {
setInterval(notify, 5000);
}
});
function notify() {
Notification.requestPermission(function(permission) {
var n = new Notification("Hi there!", {
body: 'I am here to talk about HTML5 Web Notification API',
icon: 'icon.png',
dir: 'auto'
})
setTimeout(function(){n.close()}, 2000)
})
}
我正在使用 Notification API,但我无法使其与 SetInterval() 一起使用,有人可以指出我做错了什么。只要我点击事件,通知只显示一次。这是我的代码:
document.addEventListener('DOMContentLoaded', function() {
document.getElementById('notifyBtn').addEventListener('click', function() {
if (!('Notification' in window)) {
alert('Web Notification is not supported');
return;
} else {
setInterval(Notification.requestPermission(function(permission) {
var notification = new Notification("Hi there!", {
body: 'I am here to talk about HTML5 Web Notification API',
icon: 'icon.png',
dir: 'auto'
});
setTimeout(function() {
notification.close();
}, 2000);
}),5000);
}
;
});
});
我卡在这里了,请稍等。
您需要将有效的回调传递给 setInterval()
。相反,您传递的是某种方法的 result。试试这个:
setInterval(function () {
Notification.requestPermission(function(permission) {
var notification = new Notification("Hi there!", {
body: 'I am here to talk about HTML5 Web Notification API',
icon: 'icon.png',
dir: 'auto'
});
setTimeout(notification.close, 2000);
})}, 5000);
奖励:看看我是如何简化你的 setTimeout
回调的,只传递 notification.close
方法本身,而不是在匿名函数中调用它。干净多了。
用匿名函数包装你的方法
document.addEventListener('DOMContentLoaded', function() {
document.getElementById('notifyBtn').addEventListener('click', function() {
if (!('Notification' in window)) {
alert('Web Notification is not supported');
return;
} else {
setInterval(function(){Notification.requestPermission(function(permission) {
var notification = new Notification("Hi there!", {
body: 'I am here to talk about HTML5 Web Notification API',
icon: 'icon.png',
dir: 'auto'
});
setTimeout(function() {
notification.close();
}, 2000);
})},5000);
}
;
});
});
我发现了这样的东西:
document.addEventListener('DOMContentLoaded', function() {
document.getElementById('notifyBtn').addEventListener('click', function() {
if (!('Notification' in window)) {
alert('Web Notification is not supported');
return;
} else {
setInterval(notify, 5000);
}
});
function notify() {
Notification.requestPermission(function(permission) {
var n = new Notification("Hi there!", {
body: 'I am here to talk about HTML5 Web Notification API',
icon: 'icon.png',
dir: 'auto'
})
setTimeout(function(){n.close()}, 2000)
})
}