typescript 调用方法表单 setInterval() 导致异常
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Call method form setInterval() causing exception
提问by Jviaches
I would like to call function from setInterval(). Here is the idea:
我想从 setInterval() 调用函数。这是一个想法：
class Greeter {
element: HTMLElement;
span: HTMLElement;
timerToken: number;
constructor(element: HTMLElement) {
this.element = element;
this.element.innerHTML += "The time is: ";
this.span = document.createElement('span');
this.element.appendChild(this.span);
this.span.innerText = new Date().toUTCString();
//this.element.style.cssText = "-webkit-transform:rotate(7deg)";
//this.element.style.transition = "-webkit-transform: rotate(180deg)";
}
start() {
this.timerToken = setInterval(this.runningLoop(this.element), 500);
}
stop() {
clearTimeout(this.timerToken);
}
runningLoop(element: HTMLElement) {
this.element.style.cssText = "-webkit-transform:rotate(7deg)";
}
}
window.onload = () => {
var el = document.getElementById('content');
var greeter = new Greeter(el);
greeter.start();
};
In this case i getting an exception:
在这种情况下，我得到一个例外：
Unhandled exception at line 13, column 9. Microsoft JScript runtime error: Invalid argument.
第 13 行第 9 列未处理的异常。Microsoft JScript 运行时错误：参数无效。
So i tried as following :
所以我尝试如下：
this.timerToken = setInterval(function () { this.runningLoop(this.element) }.bind, 500);
No exception but nothing happens..
没有例外，但没有任何反应..
Any ideas ?
有任何想法吗 ？
回答by Anthony Chu
setInterval(this.runningLoop(this.element), 500);
The above invokes this.runningLoopbefore passing it to setInterval, setIntervalis expecting a function but is receiving undefined. Wrap the call in an arrow function...
以上this.runningLoop在将其传递给 之前调用setInterval，setInterval正在等待一个函数但正在接收undefined。将调用包装在箭头函数中...
setInterval(() => this.runningLoop(this.element), 500);
And since you're not using the element argument in runningLoop, you can remove the argument and pass the method to setInterval...
并且由于您没有在 中使用 element 参数runningLoop，因此您可以删除该参数并将方法传递给setInterval...
setInterval(this.runningLoop, 500);
回答by Carlos Galeano
This will be looping in the time that you want: setInterval(() => function(), time in miliseconds);
这将在您想要的时间内循环： setInterval(() => function(), time in miliseconds);
Now, if you want to stop whenever! Write a var before the interval: Declare on the top of your TS file: varInterval: any; this.varInterval = setInterval(() => function(), time in miliseconds);
现在，如果你想随时停下来！在间隔前写一个var：在你的TS文件顶部声明：varInterval: any; this.varInterval = setInterval(() => function(), 时间以毫秒为单位);
You can call the method to stop like this: clearInterval(this.varInterval);
您可以像这样调用停止方法： clearInterval(this.varInterval);
This work for me!
这对我有用！
