Android上已经自动对键盘遮挡输入框做了处理，所以我们只需要关注ios。

1.首先引入 KeyboardAvoidingView

import { KeyboardAvoidingView } from 'react-native';

2.然后在页面的最外层加上 KeyboardAvoidingView

render(){

    return <KeyboardAvoidingView behavior={'padding'} style={{flex: 1}}>

        {/*具体页面内容*/}

    </KeyboardAvoidingView>

}

如果适配ios和Android，可以将页面提取出来

    getPageView = () => {

        //return 具体页面内容

    }

    getPlatformView = () => {

        if (Platform.OS === 'ios') {

            return <KeyboardAvoidingView behavior={'padding'} style={{flex: 1}}>

                    {this.getPageView()}

            </KeyboardAvoidingView>

        } else {

            return this.getPageView();

        }

    };

    render() {

        return this.getPlatformView();

    }