react native picker is not showing in android

Are you giving it width and height? That was my problem

You need to set your onValueChange method

I am trying to add picker in react native android but it does not showing in android. I map my location date to picker item but i did'nt see picker in screen.

<Picker
    style={{width: 100}} 
    selectedValue={this.state.location}
    onValueChange={(loc) => this.setState({location: loc})}>
  <Picker.Item label="Location 1" value="1" /> 
  <Picker.Item label="Location 2" value="2" />
  <Picker.Item label="Location 3" value="3" />
</Picker>

picker doesn't appear on screen if it doesn't have style with height,weight or flex property

<Picker

  style={{flex:1}} >
  <Picker.Item label="Location 1" value="1" /> 
  <Picker.Item label="Location 2" value="2" />
  <Picker.Item label="Location 3" value="3" />

</Picker>

For me, it was a "alignItems: 'center'," on the parent view component.

I would comment out all/each style of your styles.container