HarmonyOS 自定义键盘需要监听系统事件，完成收回键盘操作

@Entry
@Component
struct TextInputExample {
  controller: TextInputController = new TextInputController()
  @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() {
      Text('1221213213')
        .height('20%')
        .backgroundColor(Color.Green)
      TextArea()
        .height('20%')
        .backgroundColor(Color.Orange)
      TextInput({ controller: this.controller, text: this.inputValue })// 绑定自定义键盘
        .customKeyboard(this.CustomKeyboardBuilder()).margin(10).border({ width: 1 }).height('48vp')
      Column()
        .width('100%')
        .height('70%')
        .backgroundColor(Color.Grey)
    }.height('100%')
    .width('100%')
    .onClick(() => {
      this.controller.stopEditing()
    })
    .backgroundColor(Color.Pink)
  }
}