反应使用效应导致功能运行7次。我正在使用usecallback,但仍有很多次
带有Console.log(“运行”)的UpdateAtDedState函数在页面刷新/初始渲染上运行7次。
我只希望在AddItems状态更新时updateDedState函数一次运行。
我只有当实际的additems状态发生了变化时,使用效率要运行。我在做什么错?
export const DropdownMultiSelect = ({
data,
placeholder,
updateState,
}: IProps) => {
const [searchTerm, setSearchTerm] = useState<string>("");
const [filteredData, setFilteredData] = useState<IData[]>(data);
const [addedItems, setAddedItems] = useState<IData[]>([]);
const [placeholderValue, setPlaceholderValue] = useState<string>("");
const [inputActive, setInputActive] = useState<boolean>(false);
const onFocus = () => setInputActive(true);
const onBlur = () => {
setInputActive(false);
};
const updateAddedState = useCallback(() => {
console.log("running");
updateState(addedItems);
}, [updateState, addedItems]);
const handleFilter = (e: React.ChangeEvent<HTMLInputElement>) => {
setSearchTerm(e.target.value);
};
const handleFilterData = useCallback(
(searchTerm: string) => {
let newFilter = data.filter((value) => {
return value.name.toLowerCase().includes(searchTerm.toLowerCase());
});
for (let i = 0; i < addedItems.length; i++) {
for (let j = 0; j < newFilter.length; j++) {
if (addedItems[i].id === newFilter[j].id) {
newFilter.splice(j, 1);
}
}
}
setFilteredData(newFilter);
},
[addedItems, data]
);
const addItem = (value: IData) => {
setAddedItems([...addedItems, value]);
setSearchTerm("");
handleFilterData("");
setInputActive(false);
};
const removeItem = (value: IData, e: React.MouseEvent) => {
e.preventDefault();
let newArray: IData[] = [];
for (let i = 0; i < addedItems.length; i++) {
newArray.push(addedItems[i]);
}
for (let i = 0; i < newArray.length; i++) {
if (value.id === newArray[i].id) {
newArray.splice(i, 1);
}
}
setAddedItems(newArray);
setInputActive(true);
};
useEffect(() => {
if (addedItems.length === 1) {
setPlaceholderValue(`${addedItems.length} vald`);
} else if (addedItems.length > 1) {
setPlaceholderValue(`${addedItems.length} valda`);
} else {
setPlaceholderValue(placeholder);
}
}, [addedItems, placeholderValue, placeholder]);
useEffect(() => {
handleFilterData(searchTerm);
}, [searchTerm, addedItems, handleFilterData]);
useEffect(() => {
let isMounted = true;
if (isMounted) {
if (addedItems) {
updateAddedState();
}
}
return () => {
isMounted = false;
};
}, [updateAddedState, addedItems]);
return (
<div id="dropdownMulti">
<section className="inputSection">
<input
type="text"
placeholder={placeholderValue}
className="inputSection__input"
onChange={handleFilter}
value={searchTerm}
onFocus={onFocus}
onBlur={onBlur}
/>
<div className="inputSection__icon-container">
{inputActive ? (
<AiOutlineUpCircle
onClick={() => setInputActive(false)}
className="inputSection__icon-container--up"
/>
) : (
<AiOutlineDownCircle className="inputSection__icon-container--down" />
)}
</div>
</section>
<section className="addedItems-section">
{inputActive &&
addedItems.map((addedItem) => {
return (
<div className="addedItem" key={addedItem.id}>
<p className="addedItem__item">{addedItem?.name}</p>
<button
data-testid="remove-btn"
className="addedItem__button"
onMouseDown={(e: React.MouseEvent) =>
removeItem(addedItem, e)
}
>
<AiOutlineCloseCircle />
</button>
</div>
);
})}
</section>
{inputActive && (
<ul className="dataResult">
{filteredData.slice(0, 10).map((value) => {
return (
<li
className="dataResult__item"
key={value.id}
tabIndex={0}
onMouseDown={() => addItem(value)}
>
{value.name}
</li>
);
})}
</ul>
)}
</div>
);
};
关于如何削减其运行次数的任何提示?
The updateAddedState function with the console.log("running") is running 7 times on a page refresh/initial render.
I only want the updateAddedState function to run once when the addedItems state updates.
I only what the useEffect to run when the actual addedItems state has changed. What am I doing wrong??
export const DropdownMultiSelect = ({
data,
placeholder,
updateState,
}: IProps) => {
const [searchTerm, setSearchTerm] = useState<string>("");
const [filteredData, setFilteredData] = useState<IData[]>(data);
const [addedItems, setAddedItems] = useState<IData[]>([]);
const [placeholderValue, setPlaceholderValue] = useState<string>("");
const [inputActive, setInputActive] = useState<boolean>(false);
const onFocus = () => setInputActive(true);
const onBlur = () => {
setInputActive(false);
};
const updateAddedState = useCallback(() => {
console.log("running");
updateState(addedItems);
}, [updateState, addedItems]);
const handleFilter = (e: React.ChangeEvent<HTMLInputElement>) => {
setSearchTerm(e.target.value);
};
const handleFilterData = useCallback(
(searchTerm: string) => {
let newFilter = data.filter((value) => {
return value.name.toLowerCase().includes(searchTerm.toLowerCase());
});
for (let i = 0; i < addedItems.length; i++) {
for (let j = 0; j < newFilter.length; j++) {
if (addedItems[i].id === newFilter[j].id) {
newFilter.splice(j, 1);
}
}
}
setFilteredData(newFilter);
},
[addedItems, data]
);
const addItem = (value: IData) => {
setAddedItems([...addedItems, value]);
setSearchTerm("");
handleFilterData("");
setInputActive(false);
};
const removeItem = (value: IData, e: React.MouseEvent) => {
e.preventDefault();
let newArray: IData[] = [];
for (let i = 0; i < addedItems.length; i++) {
newArray.push(addedItems[i]);
}
for (let i = 0; i < newArray.length; i++) {
if (value.id === newArray[i].id) {
newArray.splice(i, 1);
}
}
setAddedItems(newArray);
setInputActive(true);
};
useEffect(() => {
if (addedItems.length === 1) {
setPlaceholderValue(`${addedItems.length} vald`);
} else if (addedItems.length > 1) {
setPlaceholderValue(`${addedItems.length} valda`);
} else {
setPlaceholderValue(placeholder);
}
}, [addedItems, placeholderValue, placeholder]);
useEffect(() => {
handleFilterData(searchTerm);
}, [searchTerm, addedItems, handleFilterData]);
useEffect(() => {
let isMounted = true;
if (isMounted) {
if (addedItems) {
updateAddedState();
}
}
return () => {
isMounted = false;
};
}, [updateAddedState, addedItems]);
return (
<div id="dropdownMulti">
<section className="inputSection">
<input
type="text"
placeholder={placeholderValue}
className="inputSection__input"
onChange={handleFilter}
value={searchTerm}
onFocus={onFocus}
onBlur={onBlur}
/>
<div className="inputSection__icon-container">
{inputActive ? (
<AiOutlineUpCircle
onClick={() => setInputActive(false)}
className="inputSection__icon-container--up"
/>
) : (
<AiOutlineDownCircle className="inputSection__icon-container--down" />
)}
</div>
</section>
<section className="addedItems-section">
{inputActive &&
addedItems.map((addedItem) => {
return (
<div className="addedItem" key={addedItem.id}>
<p className="addedItem__item">{addedItem?.name}</p>
<button
data-testid="remove-btn"
className="addedItem__button"
onMouseDown={(e: React.MouseEvent) =>
removeItem(addedItem, e)
}
>
<AiOutlineCloseCircle />
</button>
</div>
);
})}
</section>
{inputActive && (
<ul className="dataResult">
{filteredData.slice(0, 10).map((value) => {
return (
<li
className="dataResult__item"
key={value.id}
tabIndex={0}
onMouseDown={() => addItem(value)}
>
{value.name}
</li>
);
})}
</ul>
)}
</div>
);
};
Any tips on how to cut the number of times it runs?
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尝试删除React严格模式,它使组件仅在开发中呈现两次,而不是在生产中。如果是这种情况,请重新打开。
Try to remove React Strict Mode, it makes components render twice only in development, not in production. Put back on if it's the case.
尝试从usecallback函数的依赖项数组中删除更新函数。
如果仍无法正常工作,则定义与定义该函数的Usecallback Hook随附的Props的UpdateState函数。
Try removing updateState function from the dependency array of the useCallback function.
If it's still not working define the updateState function which comes with the props with the useCallback hook where the function is defined.