如何在 React Native 的数组中聚焦项目长度未知的 TextInput？数组中可能有更多或更少的项目来自数据库

Question

基本上我已经完成了对 TextInput 的聚焦，而项目可能会添加到购物车或来自数据库。我正在使用 useRef 挂钩，但是当我删除或添加某些项目时，出现一些错误，指出当我在购物车中删除或添加一些项目时，呈现更多或更少。

这是包含五个项目的 cartItems 数组。

[
    {
        "isAddedToCart": true,
        "product_id": "1",
        "product_name": "PIN 36MM X 18IN",
        "quantity": 0,
        "unit": undefined
    },
    {
        "isAddedToCart": true,
        "product_id": "2",
        "product_name": "APIN 42MM X 24IN",
        "quantity": 0,
        "unit": undefined
    }, {
        "isAddedToCart": true,
        "product_id": "3",
        "product_name": "PIN 24MM X 10IN",
        "quantity": 0,
        "unit": undefined
    }, {
        "isAddedToCart": true,
        "product_id": "4",
        "product_name": "RAKAB 18MM X 24IN",
        "quantity": 0,
        "unit": "2"
    }
]

这是我创建的辅助函数。


    export const inputRef = (cartItems) => {
    const inputRefs = []
    cartItems.map((item, index) => {
        if(index != (cartItems.length-1)){
            inputRefs[index] = useRef(null);
        }        
    })

    return inputRefs;
    }

这是我的文本输入

    <TextInput
    placeholder="Qty"
    placeholderTextColor="#676767"
    style={InputStyleWithoutBorder}
    onChangeText={(quantity) => inputQuantity(item.product_id, quantity, defaultUnit.default)}
    keyboardType={"numeric"}
    value={item.quantity}
    returnKeyType={inputRefs.length == index ? "done" : "next"}
    blurOnSubmit={inputRefs.length == index ? true : false}
    ref={index == 0 ? null : inputRefs[index-1]}
    onSubmitEditing={() => { 
            index == 0 || cartItems.length != index+1 ? inputRefs[index].current.focus() :null
            inputQuantity(item.product_id, item.quantity)
        }    
    }
    />

在我从购物车中添加或删除一些商品之前，它工作正常。对焦正常。

This is the item which can be deleted or can add later from the list of items

This is the error when I delete items in the cart

This is the error when I add items in the cart

Answer 1

你能试试这个解决方案吗：

export const inputRef = (cartItems) => {
  const inputRefs = useRef([])
  inputRefs.current = cartItems.map((item, index) => {
     return inputRefs.current[i] ?? createRef(null);
  })

  return inputRefs;
}

Answer 2

export const inputRef = (cartItems) => {
    const inputRefs = []
    cartItems.map((item, index) => {
        if(index != (cartItems.length-1)){
            inputRefs[index] = createRef(null);
        }        
    })
    return inputRefs;
}

This solution is working fine.

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