React Native Picker Styling - ANDROID - react-native

Question

I'm trying to add some styling to react-native picker, like underlying and set placeholder, but unable to do so.
const styles = StyleSheet.create({
picker: {
textDecorationLine: 'underline'
}
});
<Picker
style={[styles.picker]}>
<Picker.Item label="Country" value="" />
<Picker.Item label="United States" value="US" />
<Picker.Item label="India" value="IN" />
</Picker>
If i use value="", then it shows country as a selectable value, which i don't want.
textDecorationLine is not able to set the underline styling to picker.
Basically, i am looking to create something like this,
where, i can set the color of placeholder as well.
Thanks in adv.

Answer 1

Picker and Picker item's styling is handled natively on Android. You need to define style for Android's SpinnerItem in android/app/src/res/styles.xml see: How to style the standard react-native android picker?
I tried to test the underline but couldn't seem to find anything that worked. Here is couple of workarounds Android spinner with underline appcompat
However, I would simply use react native's components to our advantage. I'd create a new component that wraps React Native's Picker and put the picker in a View with the underline style that renders a placeholder if the Picker's value is undefined.

Answer 2

You can also use this one for make more attractive to your react-native picker.You can add styles to your view so it can easily make changes to your picker.
import React, { Component } from 'react';
import { View, Picker } from 'react-native';
export default class DropdownDemo extends Component{
state = { user: '' }
updateUser = (user) => {
this.setState({ user: user })
}
render(){
return(
<View
style={{
width: 300,
marginTop: 15,
marginLeft:20,
marginRight:20,
borderColor: 'black',
borderBottomWidth:1,
borderRadius: 10,
alignSelf: 'center'
}}>
<Picker
selectedValue={this.state.user}
onValueChange={this.updateUser}
>
<Picker.Item label="Male" value="Male" />
<Picker.Item label="Female" value="Female" />
<Picker.Item label="Other" value="Other" />
</Picker>
</View>
);
}
}

Answer 3

You need to modify your activity theme as follows:
<!-- Base application theme. -->
<style name="AppTheme">
<!-- Customize your theme here. -->
<item name="colorAccent">#color/colorAccent</item>
<item name="android:spinnerStyle">#style/Base.Widget.AppCompat.Spinner.Underlined</item>
...
</style>
The colorAccent controls the color of the underline, and using #style/Base.Widget.AppCompat.Spinner.Underline provides the underline on your Picker.
You can use this technique to set the styling on almost any android component in React. android:editTextStyle, android:textViewStyle, etc.
Unfortunately, because the React Picker extends Spinner and not AppCompatSpinner, the styling will be a bit different if you're running on API < 21.

Answer 4

The issue here is an assumption that Picker has the properties and styling of TextInput, which it does not. There's a related question here: Have a placeholder for react native picker where a comment outlines what you'll need to render something akin to placeholder text.
In order to achieve something like to textDecorationLine you might apply a borderBottomWidth style to the component.
Also, remember to bind the selectedValue and onValueChange props:
selectedValue={this.state.country} onValueChange={(country) => this.setState({country: country})}>

Answer 5

This is the closest I can get on iOS: https://snack.expo.io/r1L7DGb1Z
Few things to note:
1) there is itemStyle property for setting the specific style for single picker item
2) In order to get down arrow, you have to mimic it manually. You would probably like to attach it's functionality with TouchableHighlight (which isn't done in the example)
3) This doesn't look similar in the Android, so you probably need to append additional, platform specific styling.

Answer 6

This piece of the code is working on my machine:
<View style={{borderBottomWidth:1, borderColor: 'rgb(204, 204,
204)',width: "28%"}}>
<Picker
selectedValue={this.state.pickerValue}
style={[styles.textInputBox]}
onValueChange={this.onChange}>
<Picker.Item label="+31" value="+31" />
<Picker.Item label="+41" value="+41" />
<Picker.Item label="+51" value="+51" />
<Picker.Item label="+61" value="+61" />
</Picker>
</View>