What I used is onSubmitEditing props. e.g.
<TextInput style={[styles.textInput]}
placeholder="搜索"
placeholderTextColor="#bbb"
onChange={(event) => {
this.searchChange(event.nativeEvent.text)
}}
returnKeyType="search"
autoFocus={true}
value={ this.props.searchName }
selectionColor={colors.orangeColor}
onSubmitEditing={this.searchSubmit}
clearButtonMode="while-editing"
/>