您可以使用flexDirection在行中布局项。默认为列

<TouchableOpacity
  key = {index}
  onPress = {() => this._onPress(key)}
  style = {containerStyle.container}>
  <View style={containerStyle.rowContainer}>
    <Icon
      name = {Platform.OS === "ios" ? "ios-checkmark-outline" : "md-checkmark"}
      size = {24}
      style = {{ paddingLeft: 10, color: "#108EE9"}} />
    <Text
      style = {this._createStyleText(key)}>
      {key}
    </Text>
  </View>
</TouchableOpacity>

const containerStyle = StyleSheet.create({
  container: {
    padding: 8,
    backgroundColor: "#ffffff",
  },
  rowContainer: {
    flexDirection: 'row'
  }
}); 

const textStyle = StyleSheet.create({
  unselectedText: {
      paddingLeft: 45,
      color: "#000000",
      fontWeight: "normal",
  },

});

<View style={{flexDirection:'row'}}>
  <Icon
    name = {Platform.OS === "ios" ? "ios-checkmark-outline" : "md-checkmark"}
    size = {24}
    style = {{ paddingLeft: 10}} />
  <Text
    style = {this._createStyleText(key)}>
    {key}
  </Text>
</View>