Flutter 作为跨平台的U库，区别于原生技术。描述视图的Widget和View到底有啥区别。Widget到底是什么。
1、一切皆为Widget
Flutter 设计的核心思想：一切皆为Wdiget.
1.1 Widget的渲染过程
@immutable
abstract class Widget extends DiagnosticableTree {
...
/// Inflates this configuration to a concrete instance.
///
/// A given widget can be included in the tree zero or more times. In particular
/// a given widget can be placed in the tree multiple times. Each time a widget
/// is placed in the tree, it is inflated into an [Element], which means a
/// widget that is incorporated into the tree multiple times will be inflated
/// multiple times.
@protected
@factory
Element createElement();
...
}
1.1.1 关于Element
abstract class Element extends DiagnosticableTree implements BuildContext {
@nonVirtual
@override
// ignore: avoid_equals_and_hash_code_on_mutable_classes, hash_and_equals
bool operator ==(Object other) => identical(this, other);
}
1.1.2 diff
从底层Widget的代码，不难看出，Widget的数据结构是一个DiagnosticableTree, 创建Widget的过程中，调用了createElement, 从Element的代码过程中，我们也不难看出。Widget的创建过程中会创建一个与之对应的Element树，那Element树就是负责渲染的吗？
1.1.3 关于Element树的作用
Element树会对child节点去排序，遍历。找到需要更新的节点，并将节点标记为dirty
log
2023.03.28 1.1.3
