本文我们使用继承 Lazy 和 lazy 关键字实现 Viewbinding 的注入
继承 Lazy 方式
实现代码
fun <T : ViewBinding> AppCompatActivity.binding(inflate: (LayoutInflater) -> T): Lazy<T> {
return MainLazy(this, inflate)
}
class MainLazy<T : ViewBinding>(
val activity: AppCompatActivity,
val inflate: (LayoutInflater) -> T
) : Lazy<T> {
var cache: T? = null
override val value: T
get() {
if (cache == null) {
cache = inflate(activity.layoutInflater)
}
return cache!!
}
override fun isInitialized(): Boolean = cache != null
}
使用方式
val binding: ActivityMainBinding by binding(ActivityMainBinding::inflate)
lazy 关键字方式
实现代码
fun <T : ViewBinding> AppCompatActivity.bindingByLazy(inflate: (LayoutInflater) -> T)= lazy {
inflate(layoutInflater).apply {
}
}
使用方式
val binding: ActivityMainBinding by bindingByLazy(ActivityMainBinding::inflate)
