HarmonyOS 报错问题处理

@Component  
struct ViewA {  
  @ObjectLink a: ClassA;  
  @State c:number = 0  
  aboutToAppear(): void {  
    this.c = this.a.id  
  }

dialogController: CustomDialogController | null = null  
aboutToAppear(): void {  
  this.dialogController = new CustomDialogController({  
    builder: '',  
  })  
}