Answers for "how to centeralize my component using flex"

css flex vertical align

/* Answer to: "css flex vertical align" */

.box {
  display: flex;
  align-items: center; /* Vertical */
  justify-content: center; /* Horizontal */
}

.box div {
  width: 100px;
  height: 100px;
}

/*
  For more information go to:
  https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Flexible_Box_Layout/Aligning_Items_in_a_Flex_Container
*/

items in center in native

var styles = StyleSheet.create({
    content:{
        flex:1,
        flexDirection:'row',
        alignItems:'center',
        justifyContent:'center'
    },
   …
});