Question

在选项中使用哪个属性，以便在单击它时在onChange事件中获取值？

function App() {
  const [category, setCategory] = useState("");

  return (
    <div className="App">
      <select
        value={category}
        onChange={({ target: { value } }) => {
          setCategory(value);
        }}
      >
        <option ?={"1"}>{"Black"}</option>
        <option ?={"2"}>{"White"}</option>
        <option ?={"3"}>{"Pink"}</option>
        <option ?={"4"}>{"Red"}</option>
        <option ?={"5"}>{"Gray"}</option>
      </select>
    </div>
  );
}

Answer 1

您需要用于library(gganimate) library(dplyr) library(forcats) df1 <- data.frame("Time" = c("Summer", "Winter"), "Blood.Pressure" = c(21,15), "Name" = c("John","John")) df1 %>% ggplot(aes(x = Name, y = Blood.Pressure)) + geom_point(size = 5) + coord_flip() + theme(legend.position = 'none') + transition_states( fct_rev(Time), transition_length = 1, state_length = 2) + shadow_mark(color = 'black', size = 5, alpha = .25) + labs(title = "John's Blood Pressure In", subtitle = "{closest_state}", x = " ", y = "Blood Pressure")元素的属性是普通的option属性。

value

React添加到<option value={"1"}>{"Black"}</option>元素的唯一特殊添加是使用select设置所选选项的功能，而无需手动将value属性分配给{{1 }}元素。

来源：React documentation

如何给出通用价值选择？

1 个答案: