这里是React JS的新手。我有一个设置，其中我的App父组件具有 initialFormInput 状态，持有配方对象。函数从父组件传递到名为 EditRecipeButton 的子组件，该子组件可以将此状态更改为从编辑按钮调用的特定配方。
父级中的此状态通过via this.props 映射到子AddRecipe组件中的状态，我的理由是，只要父组件状态在AddRecipe中更改此状态也会发生变化。但这并没有发生，我在这里做错了什么？
这是我的代码：
var App = React.createClass({
getInitialState(){
return{
showModal:false,
recipeKeys: [ ],
recipes: [ ],
initialFormInput: {name: "", ingredients: []}
}
},
open: function(){
this.setState({showModal:true});
},
close: function(){
this.setState({showModal:false});
},
editRecipe: function(recipe){
console.log(recipe);
this.setState({initialFormInput: recipe}, function(){
this.open();
});
},
render: function(){
return(
<div className="container">
<h1>Recipe Box</h1>
<RecipeList recipes = {this.state.recipes} deleteRecipe = {this.deleteRecipe} editRecipe={this.editRecipe} />
<AddRecipeButton openModal = {this.open}/>
<AddRecipe closeModal = {this.close} showModal={this.state.showModal} addRecipeKey = {this.addRecipeKey} initialFormInput = {this.state.initialFormInput}/>
</div>
)
}
var RecipeList = function (props) {
return (
<ul className="list-group">
{
props.recipes.map( (item,index) => <RecipeItem recipe={item} deleteRecipe = {props.deleteRecipe} editRecipe={props.editRecipe}/> )
}
</ul>
);
};
var RecipeItem = React.createClass({
getInitialState: function(){
return {displayIngredients: false}
},
toggleRecipe: function() {
this.setState({displayIngredients: !this.state.displayIngredients})
},
render: function() {
return(
<li className="list-group-item" >
<h4 onClick={this.toggleRecipe}>{this.props.recipe.name}</h4>
<div style={{display: this.state.displayIngredients ? 'block' : 'none'}}>
<h5 className="text-center">Ingredients</h5>
<hr/>
<ul className="list-group" >
{this.props.recipe.ingredients.map((item) => <IngredientItem ingredient={item} />)}
</ul>
<ButtonToolbar>
<DeleteRecipeButton deleteRecipe = {this.props.deleteRecipe} recipeName={this.props.recipe.name}/>
<EditRecipeButton editRecipe = {this.props.editRecipe} recipe={this.props.recipe}/>
</ButtonToolbar>
</div>
</li>
)
}
});
var IngredientItem = function(props){
return (
<li className="list-group-item">
<p>{props.ingredient}</p>
</li>
)
};
var EditRecipeButton = React.createClass({
render: function(){
return (
<Button bsStyle="default" bsSize="small" onClick={() => this.props.editRecipe(this.props.recipe)}>Edit</Button>
)
}
});
var AddRecipe = React.createClass({
//Form in modal to add recipe
getInitialState(){
return {
name: this.props.initialFormInput.name,
ingredients: this.props.initialFormInput.ingredients
};
},
getValidationStateName(){
var length = this.state.name.length;
if(length > 0) {
return "success";
} else {
return "error";
}
},
getValidationStateIngredients(){
var length = this.state.ingredients.length;
if(length > 0){
return "success";
} else {
return "error";
}
},
handleInput: function(key,e){
var input = e.target.value;
if(key === "ingredients"){
input = e.target.value.split(",");
}
var update = {};
update[key] = input;
this.setState(update, function(){
console.log(this.state);
});
},
handleSubmit(){
var recipe = JSON.stringify({name: this.state.name, ingredients: this.state.ingredients});
localStorage.setItem(this.state.name, recipe);
var recipeObject= JSON.parse(recipe);
this.props.addRecipeKey(recipeObject);
this.props.closeModal();
this.setState({name: "", ingredients: []});
},
render: function(){
return (
<div>
<Modal show={this.props.showModal} onHide={this.props.closeModal}>
<Modal.Header closeButton>
<Modal.Title>Add a Recipe Here</Modal.Title>
</Modal.Header>
<Modal.Body>
<form>
<FormGroup controlId="formNameText" validationState = {this.getValidationStateName()}>
<ControlLabel>Recipe</ControlLabel>
<FormControl
type="text"
placeholder="Give your recipe a name"
value={this.state.name}
onInput={this.handleInput.bind(this,'name')}
/>
<FormControl.Feedback />
</FormGroup>
<br/>
<FormGroup controlId="formIngredientsTextarea" validationState = {this.getValidationStateIngredients()}>
<ControlLabel>Ingredients</ControlLabel>
<FormControl
componentClass="textarea"
placeholder="Insert your ingredients, separated by a comma"
value={this.state.ingredients}
onInput={this.handleInput.bind(this,'ingredients')}
/>
<FormControl.Feedback />
<hr/>
</FormGroup>
<Button bsStyle="primary" onClick={this.handleSubmit}>Submit</Button>
</form>
</Modal.Body>
</Modal>
</div>
)
}
});
ReactDOM.render(<App />, document.getElementById('app'));
});
因此，当父状态发生变化时，这不会改变：
getInitialState(){
return {
name: this.props.initialFormInput.name,
ingredients: this.props.initialFormInput.ingredients
};
},
答案 0 :(得分：2)
顾名思义，getInitialState仅提供组件的初始状态。后续更新不会触发该功能。
您需要实现componentWillReceiveProps以更新道具更改时的状态。来自docs：
在挂载的组件接收新道具之前调用
componentWillReceiveProps()。如果您需要更新状态以响应prop更改（例如，重置它），您可以比较this.props和nextProps并使用此方法中的this.setState()执行状态转换。 / p>请注意，即使道具没有更改，React也可以调用此方法，因此如果您只想处理更改，请确保比较当前值和下一个值。当父组件导致组件重新渲染时，可能会发生这种情况。
答案 1 :(得分：0)
如果您想跨组件共享状态，请使用redux。还为每个组件维护一个单独的文件。 此链接可能对您有所帮助 Step by Step Guide To Building React Redux Apps