How to position a View at the bottom of a ScrollView?

<ScrollView
      contentContainerStyle={{
          flexGrow: 1,
          justifyContent: 'flex-end',
      }}>
</ScrollView>

Found the best solution.

The key is the contentContainerStyle property (doc: https://facebook.github.io/react-native/docs/scrollview#contentcontainerstyle). "These styles will be applied to the scroll view content container which wraps all of the child views. "

After setting flexGrow: 1, justifyContent: 'space-between', flexDirection: 'column' in contentContainerStyle, one can set justifyContent: 'flex-start' for the upper container view with the text, and justifyContent: 'flex-end' for the lower container view with the buttons.

<ScrollView
  contentContainerStyle={{ flexGrow: 1, justifyContent: 'space-between', flexDirection: 'column' }}
  style={{ backgroundColor: 'white', paddingBottom: 20 }}
>
  <View style={{ flex: 1, justifyContent: 'flex-start' }}>
    <Text>Some text with different length in different cases, or some input fileds.</Text>
  </View>
  <View style={{ flex: 1, justifyContent: 'flex-end' }}>
    <View>
      <TouchableOpacity style={[commonStyles.greenButton, styles.buttonPadding]}>
        <Text style={commonStyles.greenButtonTitle}>Next</Text>
      </TouchableOpacity>
    </View>
    <View>
      <TouchableOpacity style={styles.cancelButtonContainer}>
        <Text style={styles.cancelButton}>Cancel</Text>
      </TouchableOpacity>
    </View>
  </View>
</ScrollView>;