问当TextInput具有焦点时，如何自动将窗口从键盘后面滑出？

EN

/**
 * Handle resizing enclosed View and scrolling to input
 * Usage:
 *    <KeyboardHandler ref='kh' offset={50}>
 *      <View>
 *        ...
 *        <TextInput ref='username'
 *          onFocus={()=>this.refs.kh.inputFocused(this,'username')}/>
 *        ...
 *      </View>
 *    </KeyboardHandler>
 * 
 *  offset is optional and defaults to 34
 *  Any other specified props will be passed on to ScrollView
 */
'use strict';

var React=require('react-native');
var {
  ScrollView,
  View,
  DeviceEventEmitter,
}=React;


var myprops={ 
  offset:34,
}
var KeyboardHandler=React.createClass({
  propTypes:{
    offset: React.PropTypes.number,
  },
  getDefaultProps(){
    return myprops;
  },
  getInitialState(){
    DeviceEventEmitter.addListener('keyboardDidShow',(frames)=>{
      if (!frames.endCoordinates) return;
      this.setState({keyboardSpace: frames.endCoordinates.height});
    });
    DeviceEventEmitter.addListener('keyboardWillHide',(frames)=>{
      this.setState({keyboardSpace:0});
    });

    this.scrollviewProps={
      automaticallyAdjustContentInsets:true,
      scrollEventThrottle:200,
    };
    // pass on any props we don't own to ScrollView
    Object.keys(this.props).filter((n)=>{return n!='children'})
    .forEach((e)=>{if(!myprops[e])this.scrollviewProps[e]=this.props[e]});

    return {
      keyboardSpace:0,
    };
  },
  render(){
    return (
      <ScrollView ref='scrollView' {...this.scrollviewProps}>
        {this.props.children}
        <View style={{height:this.state.keyboardSpace}}></View>
      </ScrollView>
    );
  },
  inputFocused(_this,refName){
    setTimeout(()=>{
      let scrollResponder=this.refs.scrollView.getScrollResponder();
      scrollResponder.scrollResponderScrollNativeHandleToKeyboard(
        React.findNodeHandle(_this.refs[refName]),
        this.props.offset, //additionalOffset
        true
      );
    }, 50);
  }
}) // KeyboardHandler

module.exports=KeyboardHandler;