Question

我正在尝试将以下代码片段转换为钩子。到目前为止，我已转换的内容不会将输出呈现为原始内容。下面是写成类组件的默认代码-

  class Area extends React.PureComponent {
  state = {
    data: [],
    tooltipX: null,
    tooltipY: null,
    tooltipIndex: null,
  };

  componentDidMount() {
    this.reorderData();
  }

  reorderData = () => {
    const reorderedData = DATA.sort((a, b) => {
      // Turn your strings into dates, and then subtract them
      // to get a value that is either negative, positive, or zero.
      return new Date(a.date) - new Date(b.date);
    });

    this.setState({
      data: reorderedData,
    });
  };

  render() {
    const { data, tooltipX, tooltipY, tooltipIndex } = this.state;
    const contentInset = { left: 10, right: 10, top: 10, bottom: 7 };

    const ChartPoints = ({ x, y, color }) =>
      data.map((item, index) => (
        <Circle
          key={index}
          cx={x(moment(item.date))}
          cy={y(item.score)}
          r={6}
          stroke={color}
          fill="white"
          onPress={() =>
            this.setState({
              tooltipX: moment(item.date),
              tooltipY: item.score,
              tooltipIndex: index,
            })
          }
        />
      ));

    return (
      <SafeAreaView style={{ flex: 1 }}>
        <View style={styles.container}>
          {data.length !== 0 ? (
            <AreaChart
              style={{ height: '70%' }}
              data={data}
              yAccessor={({ item }) => item.score}
              xAccessor={({ item }) => moment(item.date)}
              contentInset={contentInset}
              svg={{ fill: '#003F5A' }}
              numberOfTicks={10}
              yMin={0}
              yMax={10}
            >
              <Grid svg={{ stroke: 'rgba(151, 151, 151, 0.09)' }} belowChart={false} />
              <ChartPoints color="#003F5A" />
              <Tooltip
                tooltipX={tooltipX}
                tooltipY={tooltipY}
                color="#003F5A"
                index={tooltipIndex}
                dataLength={data.length}
              />
            </AreaChart>
          ) : (
            <View
              style={{
                height: '50%',
                justifyContent: 'center',
                alignItems: 'center',
              }}
            >
              <Text
                style={{
                  fontSize: 18,
                  color: '#ccc',
                }}
              >
                There are no responses for this month.
              </Text>
            </View>
          )}
          <Text style={styles.heading}>Tooltip Area Chart</Text>
        </View>
      </SafeAreaView>
    );
  }
}

下面是我转换的代码。我觉得下面的代码没有呈现工具提示，因为状态是如何在钩子中写出来的。单击时未显示工具提示。

const Area = () => {
const [ data, setData ] = useState([]);
const [ tooltipX, setTooltipX ] = useState(null);
const [ tooltipY, setTooltipY ] = useState(null);
const [ tooltipIndex, setTooltipIndex ] = useState(null);

useEffect(() => reorderData(),[]);

const reorderData = () => {
    const reorderedData = DATA.sort((a, b) => {
      // Turn your strings into dates, and then subtract them
      // to get a value that is either negative, positive, or zero.
      return new Date(a.date) - new Date(b.date);
    });
    
    setData(reorderedData);
  };

 const contentInset = { left: 10, right: 10, top: 10, bottom: 7 };
 
 const ChartPoints = ({ x, y, color }) =>
      data.map((item, index) => (
        <Circle
          key={index}
          cx={x(moment(item.date))}
          cy={y(item.score)}
          r={6}
          stroke={color}
          fill="white"
          onPress={() =>
            this.setState({
              tooltipX: moment(item.date),
              tooltipY: item.score,
              tooltipIndex: index,
            })
          }
        />
      ));

    return (
      <SafeAreaView style={{ flex: 1 }}>
        <View style={styles.container}>
          {data.length !== 0 ? (
            <AreaChart
              style={{ height: '70%' }}
              data={data}
              yAccessor={({ item }) => item.score}
              xAccessor={({ item }) => moment(item.date)}
              contentInset={contentInset}
              svg={{ fill: '#003F5A' }}
              numberOfTicks={10}
              yMin={0}
              yMax={10}
            >
              <Grid svg={{ stroke: 'rgba(151, 151, 151, 0.09)' }} belowChart={false} />
              <ChartPoints color="#003F5A" />
              <Tooltip
                tooltipX={tooltipX}
                tooltipY={tooltipY}
                color="#003F5A"
                index={tooltipIndex}
                dataLength={data.length}
              />
            </AreaChart>
          ) : (
            <View
              style={{
                height: '50%',
                justifyContent: 'center',
                alignItems: 'center',
              }}
            >
              <Text
                style={{
                  fontSize: 18,
                  color: '#ccc',
                }}
              >
                There are no responses for this month.
              </Text>
            </View>
          )}
          <Text style={styles.heading}>Tooltip Area Chart</Text>
        </View>
      </SafeAreaView>
    );
  
}

Answer 1


export default Area = () => {
  const [data, setData] = useState([]);
  const [tooltipX, setTooltipX] = useState(null);
  const [tooltipY, setTooltipY] = useState(null);
  const [tooltipIndex, setTooltipIndex] = useState(null);

  useEffect(() => reorderData(), []);

  const reorderData = () => {
    const reorderedData = DATA.sort((a, b) => {
      // Turn your strings into dates, and then subtract them
      // to get a value that is either negative, positive, or zero.
      return new Date(a.date) - new Date(b.date);
    });

    setData(reorderedData);
  };

  const contentInset = { left: 10, right: 10, top: 10, bottom: 7 };

  const ChartPoints = ({ x, y, color }) =>
    data.map((item, index) => (
      <Circle
        key={index}
        cx={x(moment(item.date))}
        cy={y(item.score)}
        r={6}
        stroke={color}
        fill="white"
        onPress={() => {
          // try this ?
          setTooltipX(moment(item.date));
          setTooltipY(item.score);
          setTooltipIndex(index);
          // try this ☝
        }}
      />
    ));

  return (
    <SafeAreaView style={{ flex: 1 }}>
      <View style={styles.container}>
        {data.length !== 0 ? (
          <AreaChart
            style={{ height: "70%" }}
            data={data}
            yAccessor={({ item }) => item.score}
            xAccessor={({ item }) => moment(item.date)}
            contentInset={contentInset}
            svg={{ fill: "#003F5A" }}
            numberOfTicks={10}
            yMin={0}
            yMax={10}
          >
            <Grid
              svg={{ stroke: "rgba(151, 151, 151, 0.09)" }}
              belowChart={false}
            />
            <ChartPoints color="#003F5A" />
            <Tooltip
              tooltipX={tooltipX}
              tooltipY={tooltipY}
              color="#003F5A"
              index={tooltipIndex}
              dataLength={data.length}
            />
          </AreaChart>
        ) : (
          <View
            style={{
              height: "50%",
              justifyContent: "center",
              alignItems: "center",
            }}
          >
            <Text
              style={{
                fontSize: 18,
                color: "#ccc",
              }}
            >
              There are no responses for this month.
            </Text>
          </View>
        )}
        <Text style={styles.heading}>Tooltip Area Chart</Text>
      </View>
    </SafeAreaView>
  );
};

将类组件转换为钩子

1 个答案: