Javascript 如何将多个参数传递给输入的 onChange 处理程序

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时间:2020-08-23 02:51:33  来源:igfitidea点击:

How to pass multiple parameters to input's onChange handler

javascriptreactjs

提问by Piotr Perak

I render collection of input elements for objects in array.

我为数组中的对象呈现输入元素的集合。

render: function() {
    var ranges = [];
    this.props.ranges.map(function(range, index) {
        var rangeElement = <Input type="text"
            value={range.name} onChange={this.changeRangeName.bind(this)} />
        ranges.push(rangeElement);
    }, this);

    // render ranges
}

this allows me to write onChange handler function:

这允许我编写 onChange 处理函数:

changeRangeName: function (event) {
    var newName = event.target.value;
},

but in this handler I need id of range object I want to change. So I could change change how I create input elements in render function and change:

但在这个处理程序中,我需要我想更改的范围对象的 id。所以我可以改变我在渲染函数中创建输入元素的方式并改变:

var rangeElement = <Input type="text"
            value={range.name}
            onChange={this.changeRangeName.bind(this, range.id)} />

Now my handler will receive range.id as parameter but now I don't have the newName value. I can get it using refs

现在我的处理程序将接收 range.id 作为参数,但现在我没有 newName 值。我可以使用 refs 得到它

var rangeElement = <Input type="text"
            ref={'range' + range.id}
            value={range.name}
            onChange={this.changeRangeName.bind(this, range.id)} />

This is the only solution I know but I suspect there is better one.

这是我知道的唯一解决方案,但我怀疑有更好的解决方案。

采纳答案by Alexandre Kirszenberg

The eventargument is still passed, but the rangeIdargument is prepended to the arguments list, so your changeRangeNamemethod would look like

event参数还通过了,但rangeId参数前置到参数列表,让你的changeRangeName方法看起来像

changeRangeName: function (rangeId, event) {
    var newName = event.target.value;
},

See Function.prototype.bind()

Function.prototype.bind()

回答by EgorTitov

I think this way is easier:

我认为这种方式更容易:

    <Input type="text"
                value={range.name}
                onChange={(e) => this.changeRangeName(range.id, e)}
        ...
    onChange(id, e) {
        ...
    }