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我試圖創建一個組件,只要將文本輸入到輸入字段中,該組件就會觸發一個事件。但是,似乎事件只會在刷新頁面或從其他組件分派事件時觸發。即使那樣它也只會發射一次。在按鍵上創建事件
如何創建只在輸入內部按鍵時分派事件的組件?如何確保遞增Counter
組件不會觸發onKeyPress
事件?
// Reducers
const counter = (state = 0, action) => {
switch (action.type) {
case 'INCREMENT':
return state + 1;
case 'DECREMENT':
return state - 1;
default:
return state;
}
};
// Store
const reducer = combineReducers(reducers);
const store = createStore(reducer);
// Components
const Counter = ({ value, onIncrement, onDecrement }) => (
<div>
<h1>{value}</h1>
<button onClick={onIncrement}>+</button>
<button onClick={onDecrement}>-</button>
</div>
);
class TestComponent extends Component {
render() {
return (
<input onKeyPress={ console.log('key pressed') } />
);
};
};
// Render
const render =() => {
ReactDOM.render(
<div>
<Counter
value={ store.getState().counter }
onIncrement={() => store.dispatch({ type: 'INCREMENT' }) }
onDecrement={() => store.dispatch({ type: 'DECREMENT' }) }
/>
<TestComponent />
</div>,
document.getElementById('root')
);
};
store.subscribe(render);
render();