HarmonyOS 如何实现自定义键盘-车牌输入

这边建议这边可以使用customKeyboard属性让自定义键盘和输入框绑定。可以参考下面例子：

@Entry
@Component
struct CustomDialogUser {
  controller: TextInputController = new TextInputController()
  @State inputValue: string = ""
  //自定义数字键盘
  @Builder CustomKeyboardBuilder() {
    Grid() {
      ForEach([1, 2, 3,'删除', 4, 5, 6,'@', 7, 8, 9,'.', '*', 0, '返回','完成'], (item:number|string) => {
        GridItem() {
          Text(item + "")
            .backgroundColor('rgb(255, 255, 255)')
            .fontColor(Color.Black)
            .width(80)
            .height(50)
            .textAlign(TextAlign.Center)
            .borderRadius(4)
            .onClick(() => {
              if(item == '返回'){
               } else if (item == '完成'){
                this.controller.stopEditing()
              } else if (item == '删除'){
                this.inputValue = this.inputValue.slice(0,this.inputValue.length-2)
              } else {
                this.inputValue += item
              }
            })
        }
      })
    }
    .height(300)
    .columnsGap(5).rowsGap(10)
    .padding(5)
    .columnsTemplate('1fr 1fr 1fr 1fr')
    .rowsTemplate('1fr 1fr 1fr 1fr ')
  }
  build() {
    Column() {
      TextInput({ placeholder: '', controller: this.controller, text: this.inputValue })
        .customKeyboard(this.CustomKeyboardBuilder()).margin(10).border({ width: 1 }).height('48vp')
    }
  }
}