求大佬告知如何模拟按键？

@Entry  
  
@Component  
  
struct TextAreaExample {  
  
  controller: TextAreaController = new TextAreaController()  
  
  @State inputValue: string = ""  
  
  // 自定义键盘组件  
  
  @Builder CustomKeyboardBuilder() {  
  
    Column() {  
      Button('x').onClick(() => {  
        // 关闭自定义键盘  
        this.controller.stopEditing()  
      })  
      Grid() {  
        ForEach([1, 2, 3, 4, 5, 6, 7, 8, 9, '*', 0, '#'], (item: number | string) => {  
          GridItem() {  
            Button(item + "")  
              .width(110).onClick(() => {  
              this.inputValue += item  
            })  
          }  
        })  
      }.maxCount(3).columnsGap(10).rowsGap(10).padding(5)  
    }.backgroundColor(Color.Gray)  
  }  
  
  build() {  
  
    Column() {  
      TextInput ({ controller: this.controller, text: this.inputValue})  
        // 绑定自定义键盘  
        .customKeyboard(this.CustomKeyboardBuilder()).margin(10).border({ width: 1 })  
    }  
  } }