fix

src/components/Canvas/FlowCanvas/manager/StateManager.ts

@@ -127,4 +127,12 @@ export class StateManager {
 	setNodesDraggable(v: boolean) { this.nodesDraggable.value = v }
 	/** 设置是否可以平移画布 */
 	setPanOnDrag(v: boolean) { this.panOnDrag.value = v }
+	/** 获取节点最大zIndex值 */
+	getMaxZIndex() {
+		return this.nodes.value.reduce((max, node) => Math.max(max, node.zIndex), 0)
+	}
+	/** 获取节点最小zIndex值 */
+	getMinZIndex() {
+		return this.nodes.value.reduce((min, node) => Math.min(min, node.zIndex), 0)
+	}
 }