index.io.js

const ExampleApp = React.createClass({
  render: function() {
    return (
      <View style={styles.container}>
        <View style={styles.borderH}></View>
        <View style={styles.contentH}>
          <View style={styles.contentV}>
            <View style={styles.contentH}>
              <View style={styles.borderV}>
              </View>
              <View style={styles.contentV}>
                <Text>content</Text>
              </View>

            </View>
            <View style={styles.borderH}>
            </View>
          </View>
          <View style={styles.borderV}>
          </View>
        </View>
      </View>
    );
  }
});

const styles = StyleSheet.create({
  container: {
    flex: 1,
    flexDirection: 'column',
    marginTop: 20
  },
  borderH: {
    height: 20,
    backgroundColor: 'blue'
  },
  borderV: {
    width: 20,
    backgroundColor: 'green'
  },
  contentH: {
    flex: 1,
    backgroundColor: '#efefef',
    flexDirection: 'row'
  },
  contentV: {
    flex: 1
  }
});