Chengzhebei/public/unityMo/export_drawingBoard.js

let saveDom = null;
let isShowSaveDom = false;

window.onDownload = function (base64string) {
    if (window.isMobile()){
        saveDom = document.querySelector('.save-image-background');
        saveDom.src = 'data:image/png;base64,' + base64string;
        saveDom.style.pointerEvents = 'auto';
        isShowSaveDom = true;
        refreshShareBlockSize();
    } else {
        let link = document.createElement('a');
        link.href = 'data:image/png;base64,' + base64string;
        link.download = 'image';
        link.click();
    }
}

window.onCancelDownload = function() {
    if (isShowSaveDom){
        saveDom.src = '';
        saveDom.style.pointerEvents = 'none';
        isShowSaveDom = false;
    }
}

window.isMobile = function () {
    return /(iPad)|(iPhone)|(iPod)|(android)|(webOS)/i.test(navigator.userAgent);
}

function refreshShareBlockSize() {
    // Unity画布宽高比
    let unityCanvasWidth = 1515;
    let unityCanvaslHeight = 780;
    let unityPanelWidth = 1150;
    let unityPanelHeight = 740;
    let unityPanelOffsetY = 0;

    let innerWidth = window.innerWidth;
    let innerHeight = window.innerHeight;

    let scale = (unityCanvasWidth / unityPanelHeight) >
    (innerWidth / innerHeight) ? (innerWidth / unityCanvasWidth) : (innerHeight / unityCanvaslHeight);

    saveDom.style.width = (unityPanelWidth * scale) + 'px';
    saveDom.style.height = (unityPanelHeight * scale) + 'px';

    if (unityPanelOffsetY > 0){
        saveDom.style.marginTop = (unityPanelOffsetY * scale * 2) + 'px';
    } else {
        saveDom.style.marginBottom = (-unityPanelOffsetY * scale * 2) + 'px';
    }
}

window.addEventListener('resize', ()=>{
    if (isShowSaveDom) refreshShareBlockSize();
});