React-Redux 连接

Question

I have two queries regarding react-redux connect

the connect can be called with two arguments mapStateToProps, mapDispatchToProps

1. Please Correct me if I am wrong, <Provider store={store}> </Provider>
   In mapStateToProps (first argument in connect())
   mapStateToProps = ( state ) => ({....})
   
   state over here is the same as store.getState(); ??
   please provider a bit more explaination to this
2. Please explain the usage of mapDispatchToProps with a beginner's example.

Answer 1

mapDispatchToProps is a function that gets dispatch function as argument. You're expected to return an object, where you map keys with a function to dispatch an action.

Example time:

connect(/* ...*/, function(dispatch) {
    return {
        sayHello: function() { dispatch("ACTION_TYPE_HELLO")}
    }
   }

Connected components will receive prop sayHello , which is a function, where this.props.sayHello() will dispatch an action ACTION_TYPE_HELLO to the store.