todoList中删除操作 onClick = {e => store.removeTodo(todo)}为什么一定要这样写？

<span onClick={ this.handleRemoveClick(todo)}>=> X</span>

handleRemoveClick = (todo)=>{
    this.props.store.removeTodo(todo)
}

会有一个这样的错误提示

Warning: Cannot update during an existing state transition (such as within `render`). Render methods should be a pure function of props and state.

这是为什么？