前面的文章中说到过项目中有用到 BPMN Modeler, 现在有个新页面要显示流程图，支持缩放、拖拽，高亮显示节点等功能，并且不能对流程图进行编辑。通过研究文档，发现可以用 NavigatedViewer来显示流程图，并支持缩放拖拽，高亮显示节点参考这个例子 实现。

下面看具体的代码

// bpmn-viewer.component.ts
import { Component, Input, OnInit, OnChanges, SimpleChanges, OnDestroy } from '@angular/core';
import { from, Observable } from 'rxjs';
import Viewer from 'camunda-bpmn-js/lib/camunda-cloud/NavigatedViewer';
 
  @Input() diagramXML;
  // 已经走过的箭头
  @Input() passedArrows = [];
  // 流程中报错的节点id
  @Input() errorNode = [];
  // 当前节点
  @Input() currentNode = [];
  // 需要设置 overlay 的节点
  @Input() overlayNode = [];
  // 是否高亮设置 overlay 所在的节点
  @Input() ifHighlightOverlayNode = false;
 
  private viewer: Viewer;
  private elementRegistry;
  private graphicsFactory;

  constructor() {
    this.viewer = new Viewer();
  }

  ngOnChanges(changes: SimpleChanges) {
    if (changes.diagramXML) {
      if (changes.diagramXML.currentValue) {
        this.diagramXML = changes.diagramXML.currentValue;
        this.importDiagram(this.diagramXML).subscribe(res => {
          this.viewer.get('canvas').zoom('fit-viewport', 'auto');
          this.elementRegistry = this.viewer.get('elementRegistry');
          this.graphicsFactory = this.viewer.get('graphicsFactory');
          this.overlays = this.viewer.get('overlays');
          this.setArrowColor();
          this.setOverlay();
        });
      }
    }
  }

  ngOnInit(): void {
    this.viewer = new Viewer({
      container: '#canvas',
      width: '100%',
      height: '100%',
      bpmnRenderer: {
        // 设置默认的线条样式
        // defaultFillColor: 'green',
        // defaultStrokeColor: 'green'
      }
    });
  }

  private setArrowColor() {
    this.passedArrows.map(item => {
      const element = this.elementRegistry.get(item);
      this.setColor(element, 'green');
    });
  }

  private setCurrentNodeColor() {
    this.currentNode.map(item => {
      const element = this.elementRegistry.get(item);
      this.setColor(element, 'green');
    });
  }


  // 几个关键的函数
  private setColor(element, color) {
    // 设置线条颜色
    element.di.set('stroke', color);
    // 设置填充的颜色
    // element.di.set('fill', fill);
    const gfx = this.elementRegistry.getGraphics(element);
    const type = element.waypoints ? 'connection' : 'shape';
    this.graphicsFactory.update(type, element, gfx);
  }

 // 导入 xml 
  private importDiagram(xml: string): Observable<{ warnings: Array<any> }> {
    return from(this.viewer.importXML(xml) as Promise<{ warnings: Array<any> }>);
  }

图片.png

// bpmn-viewer.component.html
<div class="diagram-container">
    <div id="canvas" #canvas class="canvas"></div>
</div>

最终效果图如下

图片.png