HarmonyOS Grid布局，GridItem没有等分宽度

代码如下：

Column() {
  Text(`选择存期`)
    .attributeModifier(new GlobalTextModifier(20))
    .fontWeight(FontWeight.Medium)
    .fontColor($r('app.color.black_333333'))
    .padding({ left: 15, top: 10 })
    .width('100%')
    .textAlign(TextAlign.Start)

  Grid() {
    ForEach(this.periods, (model: Record<string, string>, index: number) => {
      GridItem() {
        Stack() {
          Text(model["key"])
            .padding({
              left: 30,
              top: 10,
              right: 30,
              bottom: 10
            })
            .onClick(() => {
              if (this.periodModel!['value'] != model['value']) {
                this.rateLoading = true
                this.requestRateData(true)
              }
            })
            .attributeModifier(new GlobalTextModifier(24))
            .fontColor(this.periodModel!['value'] == model['value'] ? $r('app.color.blue_6685e6') : $r('app.color.dark_grey_666666'))
            .textAlign(TextAlign.Center)
            .onClick(() => {
              this.periodModel = model
            })
          if (this.periodModel!['value'] == model['value']) {
            Image($r('app.media.old_icon_jiaobiao'))
              .width(24)
              .width(24)
          }
        }
        .alignContent(Alignment.BottomEnd)
        .borderColor(this.periodModel!['value'] == model['value'] ?  $r('app.color.blue_6685e6') : $r('app.color.dark_grey_666666'))
        .borderWidth(0.5)
        .borderRadius(4)
      }

    }, (model: Record<string, string>) => JSON.stringify(model))
  }
  .columnsTemplate('1fr 1fr 1fr')
  .layoutDirection(GridDirection.Row)
  .margin({left: 10, right: 10, top: 10})
  .columnsGap(10)
  .rowsGap(15)
}

效果见截图