我很难理解我在下面的Redux & React原生代码中做错了什么。
我正在尝试创建一个锻炼跟踪应用程序,用户可以在其中输入他们的锻炼进度。我创建了一个“workoutSessionSlice”来跟踪状态。
const initialState: IWorkoutSessionState = {
currentTrackingEquipment: {
createdOn: { seconds: 0, nanoseconds: 0 },
equipmentName: '',
repetitions: [],
results: [],
repetitionIndex: 0,
},
hasRunningSession: false,
isTrackingEquipment: false,
savedSessionEquipmentRecords: [],
};
export const workoutSessionSlice = createSlice({
name: 'workoutSession',
initialState,
reducers: {
saveEquipmentRecord: (
state: any,
action: PayloadAction<IEquipmentRecord>,
) => {
state.savedSessionEquipmentRecords.push(action.payload);
},
addResult: (state: any, action: PayloadAction<IRepResult>) => {
state.currentTrackingEquipment.results[
state.currentTrackingEquipment.repetitionIndex
] = action.payload;
},
updateRepIndex: (state: any, action: PayloadAction<number>) => {
state.currentTrackingEquipment.repetitionIndex = action.payload;
},
},
});
用户使用某个设备,并通过一个按钮将每次重复的结果添加到状态中。我注意到,当我使用console.log在此按钮的功能中记录有效负载和状态时,状态上存在一个“延迟”:
const handleAddRep = (success: boolean, nextRepIndex: boolean) => {
console.log({
repetitions:
workOutSession.currentTrackingEquipment.results[
workOutSession.currentTrackingEquipment.repetitionIndex
].repetitions,
weight: equipmentTracking.wheelPickerValue,
success,
});
dispatch(
addResult({
repetitions:
workOutSession.currentTrackingEquipment.results[
workOutSession.currentTrackingEquipment.repetitionIndex
].repetitions,
weight: equipmentTracking.wheelPickerValue,
success,
}),
);
console.log(workOutSession);
};
控制台:
Object {
"repetitions": 15,
"success": true,
"weight": 100,
}
Object {
"currentTrackingEquipment": Object {
"createdOn": Object {
"nanoseconds": 735000000,
"seconds": 1671364848,
},
"equipmentName": "Bench-press-incline",
"repetitionIndex": 0,
"repetitions": Array [
15,
12,
7,
],
"results": Array [
Object { // expected this object to be replaced
"repetitions": 15,
"success": false,
"weight": 0,
},
Object {
"repetitions": 12,
"success": false,
"weight": 0,
},
Object {
"repetitions": 7,
"success": false,
"weight": 0,
},
],
},
"hasRunningSession": true,
"isTrackingEquipment": true,
"savedSessionEquipmentRecords": Array [],
}
当我在按钮的功能之外手动记录状态时,我确实在数组&对象中看到了正确的数据:
Object {
"currentTrackingEquipment": Object {
"createdOn": Object {
"nanoseconds": 735000000,
"seconds": 1671364848,
},
"equipmentName": "Bench-press-incline",
"repetitionIndex": 1,
"repetitions": Array [
15,
12,
7,
],
"results": Array [
Object {
"repetitions": 15,
"success": true,
"weight": 100,
},
Object {
"repetitions": 12,
"success": false,
"weight": 0,
},
Object {
"repetitions": 7,
"success": false,
"weight": 0,
},
],
},
"hasRunningSession": true,
"isTrackingEquipment": true,
"savedSessionEquipmentRecords": Array [],
}
问题是,当我想要保存记录时,这种“延迟”也会发生,导致结果数组中的最后一个对象没有更新。
onPress={() => {
Alert.alert('Successfully finished rep?', undefined, [
{
text: 'Yes',
onPress: () => {
if (
workOutSession.currentTrackingEquipment
.repetitionIndex ===
workOutSession.currentTrackingEquipment.results.length - 1
) {
handleAddRep(true, false); // Should update rep in "currentTrackingEquipment"
Alert.alert('Finished tracking equipment?', undefined, [
{
text: 'Yes',
onPress: () => {
handleFinishEquipmentTracking(); // adds current tracking equipment to "savedSessionEquipmentRecords"
},
},
{
text: 'No, go back',
},
]);
} else {
handleAddRep(true, true);
}
},
},
]);
}}
我试过设置对象键的值而不是替换整个对象,但是效果不好。任何帮助都将不胜感激!
我试过设置对象键的值而不是替换整个对象,但是效果不好。任何帮助都将不胜感激!
1条答案
按热度按时间gdx19jrr1#
没有“延迟”-您看到的是永远不会更新的旧(“过时”)数据。
请看这个例子:
仅仅因为你的状态更新为一个新值(而且它将是一个全新的对象,因为状态更新是不可变的)并不意味着你的局部变量会更新--它们仍然会指向之前的相同值。
在将来,该组件将重新呈现,然后
const something = useSelector(...)
将重新执行,然后你有了一个同名的新变量,这个新变量将有新的值(但很快又会运行stale)。