From 06a8d7f6ff842c98f313c8cc2ef5bd0fc75b9209 Mon Sep 17 00:00:00 2001
From: gx-mac <gaox2025f@gmail.com>
Date: Tue, 2 Mar 2021 16:37:36 +0800
Subject: [PATCH] fix: recalculate scrolltop when scroll.y changes

---
 src/Table.js | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/src/Table.js b/src/Table.js
index c550dbb..5356367 100644
--- a/src/Table.js
+++ b/src/Table.js
@@ -276,11 +276,22 @@ class Table extends Component {
     if (prevScrollY && currentScrollY && (prevScrollY !== currentScrollY) && this.props.lazyLoad && !this.props.ignoreScrollYChange) {
       this.bodyTable.scrollTop = 0
     } else if (this.props.ignoreScrollYChange && currentScrollY && prevScrollY && (prevScrollY !== currentScrollY)) {
-      const distance = this.bodyTable.scrollTop + (currentScrollY - prevScrollY)
-      if (distance < 0) {
-        this.bodyTable.scrollTop = 0
+      const bodyScrollTop = this.bodyTable.scrollTop
+      if (bodyScrollTop === 0) { // 在顶部的时候，滚动条不用动
+        this.bodyTable.scrollTop = 0;
       } else {
-        this.bodyTable.scrollTop = distance
+        const distance = bodyScrollTop + currentScrollY - prevScrollY;
+        if (distance < 0) {
+          this.bodyTable.scrollTop = 0;
+        } else {
+          const { scrollHeight, scrollTop } = this.bodyTable
+          const bottomDistance = Math.abs(scrollHeight - scrollTop - prevScrollY) // 在最底部的时候也不用滚动滚动条
+          if (bottomDistance < 5) { // 有些dom计算不是十分精确，设置一个值来缓冲一下
+            this.bodyTable.scrollTop = scrollTop + prevScrollY - currentScrollY
+          } else {
+            this.bodyTable.scrollTop = distance;
+          }
+        }
       }
     }
     // 是否传入 scroll中的y属性，如果传入判断是否是整数，如果是则进行比较 。bodyTable 的clientHeight进行判断