我使用Mozilla的pdf.js。我有以下代码:
<canvas id="the-canvas"/>
function displayDocument(){
PDFJS.getDocument(numberOdDocument[attachment]).then(function (pdfDoc_) {
pdfDoc = pdfDoc_;
renderPage(pageNum);
});
}
function renderPage(num) {
pdfDoc.getPage(num).then(function(page) {
var viewport = page.getViewport(scale, rotate);
canvas.height = '900';
canvas.width = '500';
var renderContext = {
canvasContext: ctx,
viewport: viewport
};
var renderTask = page.render(renderContext);
renderTask.promise.then(function () {
pageRendering = false;
if (pageNumPending !== null) {
renderPage(pageNumPending);
pageNumPending = null;
}
});
});
}
现在我只能在canvas标签中看到一页,但我想给我的canvas添加滚动条,并通过滚动来改变页面。我该怎么做?