title: How to show a drop-down menu on press of a button(TouchableHighlight) in react native
body: <p>Picker(Native component of React-native) is different from drop-down menu, but I tried implementing it too , so please help me how to do that too .  </p>
  
  <pre><code>       press(){
  
                   return (
                    &lt;Picker
                selectedValue={this.state.language}
  
                onValueChange={(lang) =&gt; this.setState({language: lang})}&gt;
                &lt;Picker.Item label="Java" value="java" /&gt;
                &lt;Picker.Item label="JavaScript" value="js" /&gt;
              &lt;/Picker&gt;
                  );
  
              }
  
              tick(){
                      this.setState({picker: true});
                    }
   var xyz= {this.state.picker} ? ({this.press}): (return(&lt;View/&gt;));
  </code></pre>
  
  <p>this is part of my render function , which contains an image button, by clicking that button I want to open a drop down menu . </p>
  
  <pre><code>&lt;TouchableHighlight
                      underlayColor="gray"
                      onPress={this.tick}
                      style=  {{flex:2,justifyContent:'center',alignItems:'center'}}&gt;
                      &lt;Image 
                      style={{height:20,width:20,}}
                      source={require('./images/add-button.png')}/&gt;
                      &lt;/TouchableHighlight&gt;
  
                      {xyz}
  </code></pre>
  
  <p>I have set the default state of picker as false in Constructor. </p>