title: React Native dynamic multiple dropdown(picker)
body: <p>I want to implement multiple pickers, the number of pickers will be based upon the value which we select in a textbox.
  The problem in dynamic picker (through loop) is that I can't use "selectedValue" property of Picker properly.Can't set value of Picker Dynamically.</p>
  
  <p>eg. code,</p>
  
  <pre><code>import React, { Component } from 'react';
  import { View, Picker } from 'react-native';
  
  let no_of_pickers = [1,2,3];//3 pickers can be increase or decreased
  export default class App extends Component {
      constructor(props) {
          super(props)
          this.state = {
              selectValue = [0,0,0]
          };
      }
  
      setValue(value,index){
          let selectValue = this.state.selectValue;
          selectValue[index] = value;
          this.setState({
            selectValue:selectValue
          });//this won't set selected value on picker
      }
      render(){
          let pickers = no_of_pickers.map((value, i) =&gt; {
              return (
                  &lt;View key={i}&gt;
                    &lt;Picker
                      selectedValue={this.state.selectValue[i]}
                      onValueChange={(itemValue, itemIndex) =&gt; {this.setValue(itemValue, i)}}&gt;
                        &lt;Picker.Item value='0' label={'Select Value'} /&gt;
                        &lt;Picker.Item value='1' label={'Value 1'} /&gt;
                        &lt;Picker.Item value='2' label={'Value 2'} /&gt;
                        &lt;Picker.Item value='3' label={'Value 3'} /&gt;
                    &lt;/Picker&gt;
                  &lt;/View&gt;
              );
          });
          return (
              {pickers}
          );
      }
  }
  </code></pre>
  
  <p>In above code the function setValue should set the picker value in UI, but only state value changed but value not selected in UI.</p>