cocos creator 3.x 通过重新 cc.screen.init(); 可以达到全屏。
cocos creator 2.x 通过以下处理 能在当前场景全屏，但是切换场景后 仍然出现黑边
var gameDiv = document.getElementById(‘Cocos2dGameContainer’);
document.documentElement.style.width = '100%';
document.documentElement.style.height = '100vh';
body.style.width = '100%';
body.style.height = '100vh';
gameDiv.style.width = '100%';
gameDiv.style.height = '100vh';
let size = body.getBoundingClientRect()
cc.game.setCanvasSize(size.width, size.height);