我有一个关于我正在工作的个人项目的问题。我需要为没有CSS的对象创建淡入和淡出效果,并且我的间隔和功能很难,因为我需要在移动到下一组功能之前完成淡出功能。
// Interval parameters
var bgtInterval = [0, false, 50];
// Fade functions will change fill following brightStep array values.
function fadeOut(){
let i = 11;
OBJECT.setAttribute("fill", brightSteps[i]);
bgtInterval[1]=true;
bgtInterval[0] = setInterval(function(){
FULLCLOCK.setAttribute("fill", brightSteps[i]);
if (i<=0){
clearInterval(bgtInterval[0]);
bgtInterval[1]=false;
}
i--;
}, bgtInterval[2]);
}
function fadeIn(){
let i = 0;
OBJECT.setAttribute("fill", brightSteps[i]);
bgtInterval[1]=true;
bgtInterval[0] = setInterval(function(){
FULLCLOCK.setAttribute("fill", brightSteps[i]);
if (i>=11){
clearInterval(bgtInterval[0]);
bgtInterval[1]=false;
}
i++;
}, bgtInterval[2]);
}
-
function resetSettings(id){
fadeOut(); // I need fadeOut to finish before I move forward
displayReset();
displayShow();
fadeIn(); // I need fadeIn to finish before I move out of this function
}
//THE MAIN FUNCTION//
resetSettings();
moreFunctionsHere();
谢谢!!!
使用Promises和async / await来实现这一目的非常简单
var bgtInterval = [0, false, 50];
// Fade functions will change fill following brightStep array values.
function fadeOut(){
// return the Promise
return new Promise(resolve => {
let i = 11;
OBJECT.setAttribute("fill", brightSteps[i]);
bgtInterval[1]=true;
bgtInterval[0] = setInterval(function(){
FULLCLOCK.setAttribute("fill", brightSteps[i]);
if (i<=0){
clearInterval(bgtInterval[0]);
bgtInterval[1]=false;
// resolve when done
resolve();
}
i--;
}, bgtInterval[2]);
});
}
function fadeIn(){
// return a Promise
return new Promise(resolve => {
let i = 0;
OBJECT.setAttribute("fill", brightSteps[i]);
bgtInterval[1]=true;
bgtInterval[0] = setInterval(function(){
FULLCLOCK.setAttribute("fill", brightSteps[i]);
if (i>=11){
clearInterval(bgtInterval[0]);
bgtInterval[1]=false;
// resolve when done
resolve();
}
i++;
}, bgtInterval[2]);
});
}
// use async so we can await a Promise
async function resetSettings(id){
// wait for fadeOut to finish
await fadeOut();
displayReset();
displayShow();
await fadeIn();
}
//THE MAIN FUNCTION//
// as we are in global scope, you can't use `async` ... so use Promise.then instead
resetSettings().then(moreFunctionsHere);
你会看到我在最后一行使用.then,因为在全局范围内你不能使用await
但是你可以这样做
(async () => {
await resetSettings();
moreFunctionsHere();
})();
一个异步IIFE所以你可以等待