docs: fix customBehavior demo

examples/interaction/customBehavior/demo/dragCanvasTwoFingers.js

@@ -1,7 +1,7 @@
 import G6 from '@antv/g6';
 
 /**
- * This demo shows how to custom a behavior to allow drag canvas with two fingers on touchpad and wheel
+ * This demo shows how to custom a behavior to allow drag and zoom canvas with two fingers on touchpad and wheel
  * By Shiwu
  */
 G6.registerBehavior('double-finger-drag-canvas', {
@@ -14,7 +14,6 @@ G6.registerBehavior('double-finger-drag-canvas', {
   onWheel: function onWheel(ev) {
     if (ev.ctrlKey) {
       const canvas = graph.get('canvas');
-      const pixelRatio = canvas.get('pixelRatio');
       const point = canvas.getPointByClient(ev.clientX, ev.clientY);
       let ratio = graph.getZoom();
       if (ev.wheelDelta > 0) {
@@ -23,8 +22,8 @@ G6.registerBehavior('double-finger-drag-canvas', {
         ratio = ratio - ratio * 0.05;
       }
       graph.zoomTo(ratio, {
-        x: point.x / pixelRatio,
-        y: point.y / pixelRatio
+        x: point.x,
+        y: point.y,
       });
     } else {
       const x = ev.deltaX || ev.movementX;
@@ -50,6 +49,8 @@ const graph = new G6.Graph({
   },
 });
 
+graph.get('canvas').set('localRefresh', false);
+
 fetch('https://gw.alipayobjects.com/os/antvdemo/assets/data/relations.json')
   .then(res => res.json())
   .then(data => {

examples/interaction/customBehavior/index.en.md

@@ -8,3 +8,4 @@ Custom a behavior when the [built-in behaviors](/en/docs/manual/middle/states/de
 ## Usage
 
 Custom a behavior with `graph.registerBehavior`, refer to [Custom Behavior Doc](/en/docs/manual/advanced/custom-behavior).
+The following demo shows how to custom a behavior to allow drag and zoom canvas with two fingers on touchpad and wheel.

examples/interaction/customBehavior/index.zh.md

@@ -8,3 +8,4 @@ order: 10
 ## 使用指南
 
 使用 `graph.registerBehavior` 自定义交互，教程参见 [自定义交互](/zh/docs/manual/advanced/custom-behavior)。
+下面示例演示了如何使用自定义交互机制实现使用鼠标滚轮或触摸板双指拖动和缩放画布。