Error in onvaluechange function in Picker Cannot read property 'props' of undefined

[waqas19921]

whenever i change value of picker following error occurs

[ryankask]

Please post a code snippet so we can better understand if this is a bug or another issue. Thanks!

[ryankask]

@facebook-github-bot label Needs more information

[waqas19921]

Here is the code i have used

constructor(props) {
    super(props);
    this.state = {
      city: ''
    };
  }

<View style={styles.field}>
            <Text>Select city</Text>
            <Picker style={styles.picker} selectedValue={this.state.city}
                    onValueChange={city=> this.setState({city: city})}>
              <Item label='None' value="-1"/>
              {this.props.cities.map((city, key)=> {
                return (
                  <Item label={city.name} key={key} value={city._id}/>
                )
              })}
            </Picker>
          </View>

[waqas19921]

Here is the picker shown

After i select the city above read screen appears saying cannot read property Props of undefined

[waqas19921]

@facebook-github-bot check now

[ryankask]

This issue is that Picker doesn't like the shape of the child Item objects. The problematic Item is the one with the label 'None'.

If you want to fix this now you should flatten the children in Picker. Check out this related PR: #8153 as it involves the same issue.

[ryankask]

@facebook-github-bot answered

[ghost]

Closing this issue as @ryankask says the question asked has been answered. Please help us by asking questions on StackOverflow. StackOverflow is amazing for Q&A: it has a reputation system, voting, the ability to mark a question as answered. Because of the reputation system it is likely the community will see and answer your question there. This also helps us use the GitHub bug tracker for bugs only.