65 lines
1.3 KiB
Dart
65 lines
1.3 KiB
Dart
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/**
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状态模式（State Pattern）
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意图：允许对象在内部状态发生改变时改变它的行为，对象看起来好像修改了它的类。
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主要解决：对象的行为依赖于它的状态（属性），并且可以根据它的状态改变而改变它的相关行为。
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何时使用：代码中包含大量与对象状态有关的条件语句。
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如何解决：将各种具体的状态类抽象出来。
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*/
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main(List<String> args) {
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Context context = Context();
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StartState startState = StartState();
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startState.doAction(context);
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print(context.state);
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StopState stopState = new StopState();
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stopState.doAction(context);
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print(context.state);
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}
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//////////////////////////////////////////////////////////////////
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///
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/// 创建一个接口
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///
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abstract class State {
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void doAction(Context context);
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}
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///
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/// 创建 Context 类
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///
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class Context {
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State state = null;
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Context();
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}
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///
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/// 创建实现接口的实体类
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///
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class StartState implements State {
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void doAction(Context context) {
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print("Player is in start state");
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context.state = this;
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}
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@override
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String toString() {
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return "Start State";
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}
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}
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class StopState implements State {
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void doAction(Context context) {
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print("Player is in stop state");
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context.state = this;
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}
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@override
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String toString() {
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return "Stop State";
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}
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}
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