fix

src/views/tool.vue

@@ -285,12 +285,12 @@ export default {
           this.tipDialogShow = true
           return
         }
+        document.documentElement.scrollTop = document.body.scrollTop == 0
         html2canvas(document.getElementById('posterOut'), {
           useCORS: true,
           backgroundColor:null,
         }).then(canvas => {
           this.posterUrl = canvas.toDataURL('image/png')
-          document.documentElement.scrollTop = document.body.scrollTop == 0
           this.showPoster = true
           this.createDialogShow = true
         })