refactor(extension): 优化细节问题

Author: fanyang

examples/feature-examples/src/pages/extensions/snapshot/index.tsx

@@ -149,7 +149,7 @@ export default function SnapshotExample() {
     if (lfRef.current) {
       setBase64Data('')
       lfRef.current
-        .getSnapshotBlob('#FFFFFF', fileType)
+        .getSnapshotBlob('#fff', fileType)
         .then(
           ({
             data,

packages/extension/src/tools/snapshot/index.ts

@@ -47,9 +47,8 @@ export class Snapshot {
       // 画布当前渲染模式和用户导出渲染模式不一致时，需要更新画布
       if (curPartial !== partial) {
         this.lf.graphModel.setPartial(partial)
-        this.lf.graphModel.eventCenter.on('graph:updated', async () => {
+        this.lf.graphModel.eventCenter.once('graph:updated', async () => {
           await this.getSnapshot(fileName, toImageOptions)
-          this.lf.graphModel.eventCenter.off('graph:updated')
           // 恢复原来渲染模式
           this.lf.graphModel.setPartial(curPartial)
         })