{"id":1420,"date":"2024-06-02T23:05:06","date_gmt":"2024-06-02T23:05:06","guid":{"rendered":""},"modified":"2024-06-05T06:12:46","modified_gmt":"2024-06-04T22:12:46","slug":"react-%e4%b9%8b-refs-%e7%9a%84%e4%bd%bf%e7%94%a8%e5%92%8c-forwardref-%e7%9a%84%e6%ba%90%e7%a0%81%e8%a7%a3%e8%af%bb","status":"publish","type":"post","link":"https:\/\/www.lccc.top\/?p=1420","title":{"rendered":"React \u4e4b Refs \u7684\u4f7f\u7528\u548c forwardRef \u7684\u6e90\u7801\u89e3\u8bfb"},"content":{"rendered":"\n

\u4e09\u79cd\u4f7f\u7528\u65b9\u5f0f<\/h2>\n

React \u63d0\u4f9b\u4e86 Refs\uff0c\u5e2e\u52a9\u6211\u4eec\u8bbf\u95ee DOM \u8282\u70b9\u6216\u5728 render \u65b9\u6cd5\u4e2d\u521b\u5efa\u7684 React \u5143\u7d20\u3002<\/p>\n

React \u63d0\u4f9b\u4e86\u4e09\u79cd\u4f7f\u7528 Ref \u7684\u65b9\u5f0f\uff1a<\/p>\n

1. String Refs<\/h3>\n
<\/p>\n
class<\/span> App<\/span> extends<\/span> React<\/span>.<\/span>Component<\/span> {<\/span>\n    constructor<\/span>(<\/span>props<\/span>)<\/span> {<\/span>\n        super<\/span>(<\/span>props<\/span>)<\/span>\n    }<\/span>\n    componentDidMount<\/span>(<\/span>)<\/span> {<\/span>\n        setTimeout<\/span>(<\/span>(<\/span>)<\/span> =><\/span> {<\/span>\n             \/\/ 2. \u901a\u8fc7 this.refs.xxx \u83b7\u53d6 DOM \u8282\u70b9<\/span>\n             this<\/span>.<\/span>refs<\/span>.<\/span>textInput<\/span>.<\/span>value<\/span> =<\/span> 'new value'<\/span>\n        }<\/span>,<\/span> 2000<\/span>)<\/span>\n    }<\/span>\n    render<\/span>(<\/span>)<\/span> {<\/span>\n        \/\/ 1. ref \u76f4\u63a5\u4f20\u5165\u4e00\u4e2a\u5b57\u7b26\u4e32<\/span>\n        return<\/span> (<\/span>\n            <<\/span>div<\/span>><\/span>\n              <<\/span>input<\/span> ref<\/span>=<\/span>\"textInput\"<\/span> value<\/span>=<\/span>'value'<\/span> \/<\/span>><\/span>\n            <<\/span>\/<\/span>div<\/span>><\/span>\n        )<\/span>\n    }<\/span>\n}<\/span>\n\nroot<\/span>.<\/span>render<\/span>(<\/span><<\/span>App<\/span> \/<\/span>><\/span>)<\/span>;<\/span><\/pre>\n<\/div>\n
2. \u56de\u8c03 Refs<\/h3>\n
<\/p>\n
class<\/span> App<\/span> extends<\/span> React<\/span>.<\/span>Component<\/span> {<\/span>\n    constructor<\/span>(<\/span>props<\/span>)<\/span> {<\/span>\n        super<\/span>(<\/span>props<\/span>)<\/span>\n    }<\/span>\n    componentDidMount<\/span>(<\/span>)<\/span> {<\/span>\n        setTimeout<\/span>(<\/span>(<\/span>)<\/span> =><\/span> {<\/span>\n              \/\/ 2. \u901a\u8fc7\u5b9e\u4f8b\u5c5e\u6027\u83b7\u53d6 DOM \u8282\u70b9<\/span>\n              this<\/span>.<\/span>textInput<\/span>.<\/span>value<\/span> =<\/span> 'new value'<\/span>\n        }<\/span>,<\/span> 2000<\/span>)<\/span>\n    }<\/span>\n    render<\/span>(<\/span>)<\/span> {<\/span>\n        \/\/ 1. ref \u4f20\u5165\u4e00\u4e2a\u56de\u8c03\u51fd\u6570<\/span>\n        \/\/ \u8be5\u51fd\u6570\u4e2d\u63a5\u53d7 React \u7ec4\u4ef6\u5b9e\u4f8b\u6216 DOM \u5143\u7d20\u4f5c\u4e3a\u53c2\u6570<\/span>\n        \/\/ \u6211\u4eec\u901a\u5e38\u4f1a\u5c06\u5176\u5b58\u50a8\u5230\u5177\u4f53\u7684\u5b9e\u4f8b\u5c5e\u6027\uff08this.textInput\uff09<\/span>\n        return<\/span> (<\/span>\n            <<\/span>div<\/span>><\/span>\n              <<\/span>input<\/span> ref<\/span>=<\/span>{<\/span>(<\/span>element<\/span>)<\/span> =><\/span> {<\/span>\n                this<\/span>.<\/span>textInput<\/span> =<\/span> element<\/span>;<\/span>\n              }<\/span>}<\/span> value<\/span>=<\/span>'value'<\/span> \/<\/span>><\/span>\n            <<\/span>\/<\/span>div<\/span>><\/span>\n        )<\/span>\n    }<\/span>\n}<\/span>\n\nroot<\/span>.<\/span>render<\/span>(<\/span><<\/span>App<\/span> \/<\/span>><\/span>)<\/span>;<\/span><\/pre>\n<\/div>\n
3. createRef<\/h3>\n
<\/p>\n
class<\/span> App<\/span> extends<\/span> React<\/span>.<\/span>Component<\/span> {<\/span>\n    constructor<\/span>(<\/span>props<\/span>)<\/span> {<\/span>\n        super<\/span>(<\/span>props<\/span>)<\/span>\n        \/\/ 1. \u4f7f\u7528 createRef \u521b\u5efa Refs<\/span>\n        \/\/ \u5e76\u5c06 Refs \u5206\u914d\u7ed9\u5b9e\u4f8b\u5c5e\u6027 textInputRef\uff0c\u4ee5\u4fbf\u5728\u6574\u4e2a\u7ec4\u4ef6\u4e2d\u5f15\u7528<\/span>\n        this<\/span>.<\/span>textInputRef<\/span> =<\/span> React<\/span>.<\/span>createRef<\/span>(<\/span>)<\/span>;<\/span>\n    }<\/span>\n    componentDidMount<\/span>(<\/span>)<\/span> {<\/span>\n        setTimeout<\/span>(<\/span>(<\/span>)<\/span> =><\/span> {<\/span>\n            \/\/ 3. \u901a\u8fc7 Refs \u7684 current \u5c5e\u6027\u8fdb\u884c\u5f15\u7528<\/span>\n            this<\/span>.<\/span>textInputRef<\/span>.<\/span>current<\/span>.<\/span>value<\/span> =<\/span> 'new value'<\/span>\n        }<\/span>,<\/span> 2000<\/span>)<\/span>\n    }<\/span>\n    render<\/span>(<\/span>)<\/span> {<\/span>\n        \/\/ 2. \u901a\u8fc7 ref \u5c5e\u6027\u9644\u52a0\u5230 React \u5143\u7d20<\/span>\n        return<\/span> (<\/span>\n            <<\/span>div<\/span>><\/span>\n              <<\/span>input<\/span> ref<\/span>=<\/span>{<\/span>this<\/span>.<\/span>textInputRef<\/span>}<\/span> value<\/span>=<\/span>'value'<\/span> \/<\/span>><\/span>\n            <<\/span>\/<\/span>div<\/span>><\/span>\n        )<\/span>\n    }<\/span>\n}<\/span><\/pre>\n<\/div>\n
\u8fd9\u662f\u6700\u88ab\u63a8\u8350\u4f7f\u7528\u7684\u65b9\u5f0f\u3002<\/p>\n
\u4e24\u79cd\u4f7f\u7528\u76ee\u7684<\/h2>\n
Refs \u9664\u4e86\u7528\u4e8e\u83b7\u53d6\u5177\u4f53\u7684 DOM \u8282\u70b9\u5916\uff0c\u4e5f\u53ef\u4ee5\u83b7\u53d6 Class \u7ec4\u4ef6\u7684\u5b9e\u4f8b\uff0c\u5f53\u83b7\u53d6\u5230\u5b9e\u4f8b\u540e\uff0c\u53ef\u4ee5\u8c03\u7528\u5176\u4e2d\u7684\u65b9\u6cd5\uff0c\u4ece\u800c\u5f3a\u5236\u6267\u884c\uff0c\u6bd4\u5982\u52a8\u753b\u4e4b\u7c7b\u7684\u6548\u679c\u3002<\/p>\n
\u6211\u4eec\u4e3e\u4e00\u4e2a\u83b7\u53d6\u7ec4\u4ef6\u5b9e\u4f8b\u7684\u4f8b\u5b50\uff1a<\/p>\n
<\/p>\n
class<\/span> Input<\/span> extends<\/span> React<\/span>.<\/span>Component<\/span> {<\/span>\n    constructor<\/span>(<\/span>props<\/span>)<\/span> {<\/span>\n        super<\/span>(<\/span>props<\/span>)<\/span>\n        this<\/span>.<\/span>textInputRef<\/span> =<\/span> React<\/span>.<\/span>createRef<\/span>(<\/span>)<\/span>;<\/span>\n    }<\/span>\n    handleFocus<\/span>(<\/span>)<\/span> {<\/span>\n        this<\/span>.<\/span>textInputRef<\/span>.<\/span>current<\/span>.<\/span>focus<\/span>(<\/span>)<\/span>;<\/span>\n    }<\/span>\n    render<\/span>(<\/span>)<\/span> {<\/span>\n        return<\/span> <<\/span>input<\/span> ref<\/span>=<\/span>{<\/span>this<\/span>.<\/span>textInputRef<\/span>}<\/span> value<\/span>=<\/span>'value'<\/span> \/<\/span>><\/span>\n    }<\/span>\n}<\/span>\n\nclass<\/span> App<\/span> extends<\/span> React<\/span>.<\/span>Component<\/span> {<\/span>\n    constructor<\/span>(<\/span>props<\/span>)<\/span> {<\/span>\n        super<\/span>(<\/span>props<\/span>)<\/span>\n        this<\/span>.<\/span>inputRef<\/span> =<\/span> React<\/span>.<\/span>createRef<\/span>(<\/span>)<\/span>;<\/span>\n    }<\/span>\n    componentDidMount<\/span>(<\/span>)<\/span> {<\/span>\n        setTimeout<\/span>(<\/span>(<\/span>)<\/span> =><\/span> {<\/span>\n                this<\/span>.<\/span>inputRef<\/span>.<\/span>current<\/span>.<\/span>handleFocus<\/span>(<\/span>)<\/span>\n        }<\/span>,<\/span> 2000<\/span>)<\/span>\n    }<\/span>\n    render<\/span>(<\/span>)<\/span> {<\/span>\n        return<\/span> (<\/span>\n            <<\/span>div<\/span>><\/span>\n              <<\/span>Input<\/span> ref<\/span>=<\/span>{<\/span>this<\/span>.<\/span>inputRef<\/span>}<\/span> value<\/span>=<\/span>'value'<\/span> \/<\/span>><\/span>\n            <<\/span>\/<\/span>div<\/span>><\/span>\n        )<\/span>\n    }<\/span>\n}<\/span><\/pre>\n<\/div>\n
\u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0c\u6211\u4eec\u901a\u8fc7 this.inputRef.current<\/code> \u83b7\u53d6\u5230 Input \u7ec4\u4ef6\u7684\u5b9e\u4f8b\uff0c\u5e76\u8c03\u7528\u4e86\u5b9e\u4f8b\u7684 handleFocus \u65b9\u6cd5\uff0c\u5728\u8fd9\u4e2a\u65b9\u6cd5\u4e2d\uff0c\u53c8\u901a\u8fc7 Refs \u83b7\u53d6\u5230\u5177\u4f53\u7684 DOM \u5143\u7d20\uff0c\u6267\u884c\u4e86 focus \u539f\u751f\u65b9\u6cd5\u3002<\/p>\n
forwardRef<\/h2>\n
\u6ce8\u610f\u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0c\u6211\u4eec\u7684 Input \u7ec4\u4ef6\u4f7f\u7528\u7684\u662f\u7c7b\u7ec4\u4ef6\uff0cInput \u7ec4\u4ef6\u53ef\u4ee5\u6539\u4e3a\u4f7f\u7528\u51fd\u6570\u7ec4\u4ef6\u5417\uff1f<\/p>\n
\u7b54\u6848\u662f\u4e0d\u53ef\u4ee5\uff0c\u6211\u4eec\u4e0d\u80fd\u5728\u51fd\u6570\u7ec4\u4ef6\u4e0a\u4f7f\u7528 ref \u5c5e\u6027\uff0c\u56e0\u4e3a\u51fd\u6570\u7ec4\u4ef6\u6ca1\u6709\u5b9e\u4f8b\u3002<\/p>\n
\u5982\u679c\u6211\u4eec\u5f3a\u884c\u4f7f\u7528\uff0cReact \u4f1a\u62a5\u9519\u5e76\u63d0\u793a\u6211\u4eec\u7528 forwardRef\uff1a<\/p>\n
<\/p>\n
function<\/span> Input<\/span>(<\/span>)<\/span> {<\/span>\n  return<\/span> <<\/span>input<\/span> value<\/span>=<\/span>'value'<\/span> \/<\/span>><\/span>\n}<\/span>\n\nclass<\/span> App<\/span> extends<\/span> React<\/span>.<\/span>Component<\/span> {<\/span>\n    constructor<\/span>(<\/span>props<\/span>)<\/span> {<\/span>\n        super<\/span>(<\/span>props<\/span>)<\/span>\n        this<\/span>.<\/span>inputRef<\/span> =<\/span> React<\/span>.<\/span>createRef<\/span>(<\/span>)<\/span>;<\/span>\n    }<\/span>\n    render<\/span>(<\/span>)<\/span> {<\/span>\n        return<\/span> (<\/span>\n            <<\/span>div<\/span>><\/span>\n              <<\/span>Input<\/span> ref<\/span>=<\/span>{<\/span>this<\/span>.<\/span>inputRef<\/span>}<\/span> value<\/span>=<\/span>'value'<\/span> \/<\/span>><\/span>\n            <<\/span>\/<\/span>div<\/span>><\/span>\n        )<\/span>\n    }<\/span>\n}<\/span><\/pre>\n<\/div>\n
\"image.png\"<\/a><\/p>\n
\u4f46\u662f\u5462\uff0c\u5bf9\u4e8e\u201c\u83b7\u53d6\u7ec4\u4ef6\u5b9e\u4f8b\uff0c\u8c03\u7528\u5b9e\u4f8b\u65b9\u6cd5\u201d\u8fd9\u4e2a\u9700\u6c42\uff0c\u5373\u4f7f\u4f7f\u7528 forwardRef \u4e5f\u505a\u4e0d\u5230\uff0c\u501f\u52a9 forwardRef \u540e\uff0c\u6211\u4eec\u4e5f\u5c31\u662f\u8ddf\u7c7b\u7ec4\u4ef6\u4e00\u6837\uff0c\u53ef\u4ee5\u5728\u7ec4\u4ef6\u4e0a\u4f7f\u7528 ref \u5c5e\u6027\uff0c\u7136\u540e\u5c06 ref \u7ed1\u5b9a\u5230\u5177\u4f53\u7684 DOM \u5143\u7d20\u6216\u8005 class \u7ec4\u4ef6\u4e0a\uff0c\u4e5f\u5c31\u662f\u6211\u4eec\u5e38\u8bf4\u7684 Refs \u8f6c\u53d1\u3002<\/p>\n
Refs \u8f6c\u53d1<\/h2>\n
\u6709\u7684\u65f6\u5019\uff0c\u6211\u4eec\u5f00\u53d1\u4e00\u4e2a\u7ec4\u4ef6\uff0c\u8fd9\u4e2a\u7ec4\u4ef6\u9700\u8981\u5bf9\u7ec4\u4ef6\u4f7f\u7528\u8005\u63d0\u4f9b\u4e00\u4e2a ref \u5c5e\u6027\uff0c\u7528\u4e8e\u8ba9\u7ec4\u4ef6\u4f7f\u7528\u8005\u83b7\u53d6\u5177\u4f53\u7684 DOM \u5143\u7d20\uff0c\u6211\u4eec\u5c31\u9700\u8981\u8fdb\u884c Refs \u8f6c\u53d1\uff0c\u6211\u4eec\u901a\u5e38\u7684\u505a\u6cd5\u662f\uff1a<\/p>\n
<\/p>\n
\/\/ \u7c7b\u7ec4\u4ef6<\/span>\nclass<\/span> Child<\/span> extends<\/span> React<\/span>.<\/span>Component<\/span> {<\/span>\n    render<\/span>(<\/span>)<\/span> {<\/span>\n        const<\/span> {<\/span>inputRef,<\/span> ...rest<\/span>}<\/span> =<\/span> this<\/span>.<\/span>props<\/span>;<\/span>\n        \/\/ 3. \u8fd9\u91cc\u5c06 props \u4e2d\u7684 inputRef \u8d4b\u7ed9 DOM \u5143\u7d20\u7684 ref<\/span>\n        return<\/span> <<\/span>input<\/span> ref<\/span>=<\/span>{<\/span>inputRef<\/span>}<\/span> {<\/span>...rest<\/span>}<\/span> placeholder<\/span>=<\/span>\"value\"<\/span> \/<\/span>><\/span>\n    }<\/span>\n}<\/span>\n\/\/ \u51fd\u6570\u7ec4\u4ef6<\/span>\nfunction<\/span> Child<\/span>(<\/span>props<\/span>)<\/span> {<\/span>\n      const<\/span> {<\/span>inputRef,<\/span> ...rest<\/span>}<\/span> =<\/span> props<\/span>;<\/span>\n      \/\/ 3. \u8fd9\u91cc\u5c06 props \u4e2d\u7684 inputRef \u8d4b\u7ed9 DOM \u5143\u7d20\u7684 ref<\/span>\n      return<\/span> <<\/span>input<\/span> ref<\/span>=<\/span>{<\/span>inputRef<\/span>}<\/span> {<\/span>...rest<\/span>}<\/span> placeholder<\/span>=<\/span>\"value\"<\/span> \/<\/span>><\/span>\n}<\/span>\n\nclass<\/span> Parent<\/span> extends<\/span> React<\/span>.<\/span>Component<\/span> {<\/span>\n    constructor<\/span>(<\/span>props<\/span>)<\/span> {<\/span>\n        super<\/span>(<\/span>props<\/span>)<\/span>\n        \/\/ 1. \u521b\u5efa refs<\/span>\n        this<\/span>.<\/span>inputRef<\/span> =<\/span> React<\/span>.<\/span>createRef<\/span>(<\/span>)<\/span>;<\/span>\n    }<\/span>\n    componentDidMount<\/span>(<\/span>)<\/span> {<\/span>\n        setTimeout<\/span>(<\/span>(<\/span>)<\/span> =><\/span> {<\/span>\n            \/\/ 4. \u4f7f\u7528 this.inputRef.current \u83b7\u53d6\u5b50\u7ec4\u4ef6\u4e2d\u6e32\u67d3\u7684 DOM \u8282\u70b9<\/span>\n            this<\/span>.<\/span>inputRef<\/span>.<\/span>current<\/span>.<\/span>value<\/span> =<\/span> 'new value'<\/span>\n        }<\/span>,<\/span> 2000<\/span>)<\/span>\n    }<\/span>\n    render<\/span>(<\/span>)<\/span> {<\/span>\n        \/\/ 2. \u56e0\u4e3a ref \u5c5e\u6027\u4e0d\u80fd\u901a\u8fc7 this.props \u83b7\u53d6\uff0c\u6240\u4ee5\u8fd9\u91cc\u6362\u4e86\u4e00\u4e2a\u5c5e\u6027\u540d<\/span>\n        return<\/span> <<\/span>Child<\/span> inputRef<\/span>=<\/span>{<\/span>this<\/span>.<\/span>inputRef<\/span>}<\/span> \/<\/span>><\/span>\n    }<\/span>\n}<\/span><\/pre>\n<\/div>\n
React \u63d0\u4f9b\u4e86 forwardRef \u8fd9\u4e2a API\uff0c\u6211\u4eec\u76f4\u63a5\u770b\u4f7f\u7528\u793a\u4f8b\uff1a<\/p>\n
<\/p>\n
\/\/ 3. \u5b50\u7ec4\u4ef6\u901a\u8fc7 forwardRef \u83b7\u53d6 ref\uff0c\u5e76\u901a\u8fc7 ref \u5c5e\u6027\u7ed1\u5b9a React \u5143\u7d20<\/span>\nconst<\/span> Child<\/span> =<\/span> forwardRef<\/span>(<\/span>(<\/span>props<\/span>,<\/span> ref<\/span>)<\/span> =><\/span> (<\/span>\n  <<\/span>input<\/span> ref<\/span>=<\/span>{<\/span>ref<\/span>}<\/span> placeholder<\/span>=<\/span>\"value\"<\/span> \/<\/span>><\/span>\n)<\/span>)<\/span>;<\/span>\n\nclass<\/span> Parent<\/span> extends<\/span> React<\/span>.<\/span>Component<\/span> {<\/span>\n    constructor<\/span>(<\/span>props<\/span>)<\/span> {<\/span>\n        super<\/span>(<\/span>props<\/span>)<\/span>\n        \/\/ 1. \u521b\u5efa refs<\/span>\n        this<\/span>.<\/span>inputRef<\/span> =<\/span> React<\/span>.<\/span>createRef<\/span>(<\/span>)<\/span>;<\/span>\n    }<\/span>\n    componentDidMount<\/span>(<\/span>)<\/span> {<\/span>\n        setTimeout<\/span>(<\/span>(<\/span>)<\/span> =><\/span> {<\/span>\n            \/\/ 4. \u4f7f\u7528 this.inputRef.current \u83b7\u53d6\u5b50\u7ec4\u4ef6\u4e2d\u6e32\u67d3\u7684 DOM \u8282\u70b9<\/span>\n            this<\/span>.<\/span>inputRef<\/span>.<\/span>current<\/span>.<\/span>value<\/span> =<\/span> 'new value'<\/span>\n        }<\/span>,<\/span> 2000<\/span>)<\/span>\n    }<\/span>\n    render<\/span>(<\/span>)<\/span> {<\/span>\n        \/\/ 2. \u4f20\u7ed9\u5b50\u7ec4\u4ef6\u7684 ref \u5c5e\u6027<\/span>\n        return<\/span> <<\/span>Child<\/span> ref<\/span>=<\/span>{<\/span>this<\/span>.<\/span>inputRef<\/span>}<\/span> \/<\/span>><\/span>\n    }<\/span>\n}<\/span><\/pre>\n<\/div>\n
\u5c24\u5176\u662f\u5728\u6211\u4eec\u7f16\u5199\u9ad8\u9636\u7ec4\u4ef6\u7684\u65f6\u5019\uff0c\u5f80\u5f80\u8981\u5b9e\u73b0 refs \u8f6c\u53d1\u3002\u6211\u4eec\u77e5\u9053\uff0c\u4e00\u4e2a\u9ad8\u9636\u7ec4\u4ef6\uff0c\u4f1a\u63a5\u53d7\u4e00\u4e2a\u7ec4\u4ef6\uff0c\u8fd4\u56de\u4e00\u4e2a\u5305\u88f9\u540e\u7684\u65b0\u7ec4\u4ef6\uff0c\u4ece\u800c\u5b9e\u73b0\u67d0\u79cd\u529f\u80fd\u7684\u589e\u5f3a\u3002<\/p>\n
\u4f46\u4e5f\u6b63\u662f\u5982\u6b64\uff0c\u6211\u4eec\u6dfb\u52a0 ref\uff0c\u83b7\u53d6\u7684\u4f1a\u662f\u5305\u88f9\u540e\u7684\u65b0\u7ec4\u4ef6\u7684\u5b9e\u4f8b\uff0c\u800c\u975e\u88ab\u5305\u88f9\u7684\u7ec4\u4ef6\u5b9e\u4f8b\uff0c\u8fd9\u5c31\u53ef\u80fd\u4f1a\u5bfc\u81f4\u4e00\u4e9b\u95ee\u9898\u3002<\/p>\n
createRef \u6e90\u7801<\/h2>\n
\u73b0\u5728\u6211\u4eec\u770b\u4e0b createRef<\/code> \u7684\u6e90\u7801\uff0c\u6e90\u7801\u7684\u4f4d\u7f6e<\/a>\u5728 \/packages\/react\/src\/ReactCreateRef.js<\/code>\uff0c\u4ee3\u7801\u5176\u5b9e\u5f88\u7b80\u5355\uff0c\u5c31\u53ea\u662f\u8fd4\u56de\u4e86\u4e00\u4e2a\u5177\u6709 current \u5c5e\u6027\u7684\u5bf9\u8c61\uff1a<\/p>\n
<\/p>\n
\/\/ \u7b80\u5316\u540e<\/span>\nexport<\/span> function<\/span> createRef<\/span>(<\/span>)<\/span> {<\/span>\n  const<\/span> refObject<\/span> =<\/span> {<\/span>\n    current<\/span>: null<\/span>,<\/span>\n  }<\/span>;<\/span>\n  return<\/span> refObject<\/span>;<\/span>\n}<\/span><\/pre>\n<\/div>\n
\u5728\u6e32\u67d3\u7684\u8fc7\u7a0b\u4e2d\uff0crefObject.current<\/code> \u4f1a\u88ab\u8d4b\u4e88\u5177\u4f53\u7684\u503c\u3002<\/p>\n
forwardRef \u6e90\u7801<\/h2>\n
\u90a3 forwardRef \u6e90\u7801\u5462\uff1f\u6e90\u7801\u7684\u4f4d\u7f6e<\/a>\u5728 \/packages\/react\/src\/ReactForwardRef.js<\/code>\uff0c\u4ee3\u7801\u4e5f\u5f88\u7b80\u5355\uff1a<\/p>\n
<\/p>\n
\/\/ \u7b80\u5316\u540e<\/span>\nconst<\/span> REACT_FORWARD_REF_TYPE<\/span> =<\/span> Symbol<\/span>.<\/span>for<\/span>(<\/span>'react.forward_ref'<\/span>)<\/span>;<\/span>\n\nexport<\/span> function<\/span> forwardRef<\/span>(<\/span>render<\/span>)<\/span> {<\/span>\n  const<\/span> elementType<\/span> =<\/span> {<\/span>\n    $$typeof<\/span>: REACT_FORWARD_REF_TYPE<\/span>,<\/span>\n    render,<\/span>\n  }<\/span>;<\/span>\n\n  return<\/span> elementType<\/span>;<\/span>\n}<\/span><\/pre>\n<\/div>\n
\u4f46\u662f\u8981\u6ce8\u610f\u8fd9\u91cc\u7684 $$typeof<\/code>\uff0c\u5c3d\u7ba1\u8fd9\u91cc\u662f REACT_FORWARD_REF_TYPE<\/code>\uff0c\u4f46\u6700\u7ec8\u521b\u5efa\u7684 React \u5143\u7d20\u7684 $$typeof<\/code> \u4f9d\u7136\u4e3a REACT_ELEMENT_TYPE<\/code>\u3002<\/p>\n
\u5173\u4e8e createElement<\/code> \u7684\u6e90\u7801\u5206\u6790\u53c2\u8003 \u300aReact \u4e4b createElement \u6e90\u7801\u89e3\u8bfb\u300b<\/a>\uff0c\u6211\u4eec\u8fd9\u91cc\u7b80\u5355\u5206\u6790\u4e00\u4e0b\uff0c\u4ee5 InputComponent<\/code> \u4e3a\u4f8b\uff1a<\/p>\n
<\/p>\n
\/\/ \u4f7f\u7528 forwardRef<\/span>\nconst<\/span> InputComponent<\/span> =<\/span> forwardRef<\/span>(<\/span>(<\/span>{<\/span>value}<\/span>,<\/span> ref<\/span>)<\/span> =><\/span> (<\/span>\n  <<\/span>input<\/span> ref<\/span>=<\/span>{<\/span>ref<\/span>}<\/span> className<\/span>=<\/span>\"FancyButton\"<\/span> value<\/span>=<\/span>{<\/span>value<\/span>}<\/span> \/<\/span>><\/span>\n)<\/span>)<\/span>;<\/span>\n\n\/\/ \u6839\u636e forwardRef \u7684\u6e90\u7801\uff0c\u6700\u7ec8\u8fd4\u56de\u7684\u5bf9\u8c61\u683c\u5f0f\u4e3a\uff1a<\/span>\nconst<\/span> InputComponent<\/span> =<\/span> {<\/span>\n    $$typeof<\/span>: REACT_FORWARD_REF_TYPE<\/span>,<\/span>\n    render,<\/span>\n}<\/span>\n\n\/\/ \u4f7f\u7528\u7ec4\u4ef6<\/span>\nconst<\/span> result<\/span> =<\/span> <<\/span>InputComponent<\/span> \/<\/span>><\/span>\n  \n\/\/ Bable \u5c06\u5176\u8f6c\u8bd1\u4e3a\uff1a<\/span>\nconst<\/span> result<\/span> =<\/span> React<\/span>.<\/span>createElement<\/span>(<\/span>InputComponent<\/span>,<\/span> null<\/span>)<\/span>;<\/span>\n\n\/\/ \u6700\u7ec8\u8fd4\u56de\u7684\u5bf9\u8c61\u4e3a\uff1a<\/span>\nconst<\/span> result<\/span> =<\/span> {<\/span>\n  $$typeof<\/span>: REACT_ELEMENT_TYPE<\/span>,<\/span>\n  type<\/span>: {<\/span>\n    $$typeof<\/span>: REACT_FORWARD_REF_TYPE<\/span>,<\/span>\n    render,<\/span>\n  }<\/span>\n}<\/span><\/pre>\n<\/div>\n
\u6211\u4eec\u5c1d\u8bd5\u7740\u6253\u5370\u4e00\u4e0b\u6700\u7ec8\u8fd4\u56de\u7684\u5bf9\u8c61\uff0c\u786e\u5b9e\u4e5f\u662f\u8fd9\u6837\u7684\u7ed3\u6784\uff1a<\/p>\n
\"image.png\"<\/a><\/p>\n
React \u7cfb\u5217<\/h2>\n
\u8bb2\u89e3 React \u6e90\u7801\u3001React API \u80cc\u540e\u7684\u5b9e\u73b0\u673a\u5236\uff0cReact \u6700\u4f73\u5b9e\u8df5\u3001React \u7684\u53d1\u5c55\u4e0e\u5386\u53f2\u7b49\uff0c\u9884\u8ba1 50 \u7bc7\u5de6\u53f3\uff0c\u6b22\u8fce\u5173\u6ce8<\/p>\n
\u5982\u679c\u559c\u6b22\u6216\u8005\u6709\u6240\u542f\u53d1\uff0c\u6b22\u8fce star\uff0c\u5bf9\u4f5c\u8005\u4e5f\u662f\u4e00\u79cd\u9f13\u52b1\u3002<\/p>\n<\/td>\n
\u6587\u7ae0\u8f6c\u8f7d\u81eahttps:\/\/github.com\/mqyqingfeng\/Blog\/issues\/318<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"
\u4e09\u79cd\u4f7f\u7528\u65b9\u5f0f React \u63d0\u4f9b\u4e86 Refs\uff0c\u5e2e\u52a9\u6211\u4eec\u8bbf\u95ee DOM \u8282\u70b9\u6216\u5728 render \u65b9\u6cd5\u4e2d\u521b\u5efa\u7684 React \u5143\u7d20\u3002 React \u63d0\u4f9b\u4e86\u4e09\u79cd\u4f7f\u7528 Ref …<\/p>\n
 Read More  Read More<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-1420","post","type-post","status-publish","format-standard","hentry","category-learn"],"_links":{"self":[{"href":"https:\/\/www.lccc.top\/index.php?rest_route=\/wp\/v2\/posts\/1420"}],"collection":[{"href":"https:\/\/www.lccc.top\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.lccc.top\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.lccc.top\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.lccc.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1420"}],"version-history":[{"count":1,"href":"https:\/\/www.lccc.top\/index.php?rest_route=\/wp\/v2\/posts\/1420\/revisions"}],"predecessor-version":[{"id":2394,"href":"https:\/\/www.lccc.top\/index.php?rest_route=\/wp\/v2\/posts\/1420\/revisions\/2394"}],"wp:attachment":[{"href":"https:\/\/www.lccc.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1420"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.lccc.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1420"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.lccc.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1420"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}