Двлвдад Ввдвдвдвдвв's questions

override fun <T : ViewModel> create(modelClass: Class<T>): T = when {
    modelClass.isAssignableFrom(M1ViewModel::class.java) -> M1ViewModel(dataManager, schedulerProvider)
    modelClass.isAssignableFrom(C1ViewModel::class.java) -> C1ViewModel(dataManager, schedulerProvider)
    modelClass.isAssignableFrom(C2ViewModel::class.java) -> C2ViewModel(dataManager, schedulerProvider)
    else -> throw IllegalArgumentException("Unknown ViewModel class: " + modelClass.name)
} as T

这是代码

怎样才能把代码最小化，这样就不用每次都写了

modelClass.isAssignableFrom(C2ViewModel::class.java) -> C2ViewModel(dataManager, schedulerProvider)

当使用Column时，不显示工作表中的元素，如果使用Row，则显示。

Widget _buildRow(Banner banner) {
  return Card(
    child: Container(
      child: Column(
        children: [
          Text(banner.title),
          Expanded(
            child: Image.network(banner.image)
          )
        ],
      ),
    )
  );}