2017-10-26

聚沙

State Updates May Be Asynchronous

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// Wrong
this.setState({
  counter: this.state.counter + this.props.increment,
});

仍然是错误的：

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// Wrong
const { counter } = this.state;
const { increment } = this.props;

this.setState({
  counter: counter + increment,
});

正确的用法：

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// Correct
this.setState((prevState, props) => ({
  counter: prevState.counter + props.increment
}));

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