响应选择器中的本机状态更改问题

时间:2019-03-30 20:57:27

标签: react-native expo

在对本地选择器做出反应时,父母和精神科医生之间的状态没有改变。即使我们选择精神病医生,也只去父母按钮吗?

               <Picker style = {styles.input1}
                  selectedValue={this.state.selectedValue}
                  onValueChange={(itemValue, itemIndex) =>
                    this.setState({designation: itemValue})
                  }>
                  <Picker.Item label="Parent" value="Parent" />
                  <Picker.Item label="Psychiatrist" value="Psychiatrist" />
                  <Picker.Item label="NA" value="NA" />
                </Picker>

2 个答案:

答案 0 :(得分:0)

在onValueChange中,您要设置State“名称”,而应更改选择器的selectedValue的状态:“ selectedValue”。

<Picker style = {styles.input1}
   selectedValue={this.state.selectedValue}
   onValueChange={(itemValue, itemIndex) =>
   this.setState({selectedValue: itemValue})
   }>
   <Picker.Item label="Parent" value="Parent" />
   <Picker.Item label="Psychiatrist" value="Psychiatrist" />
   <Picker.Item label="NA" value="NA" />
</Picker>

答案 1 :(得分:0)

您没有在所选值中设置正确的状态。将选定的值设置为this.state.designation

                <Picker style = {styles.input1}
                  selectedValue={this.state.designation}
                  onValueChange={(itemValue, itemIndex) =>
                    this.setState({designation: itemValue})
                  }>
                  <Picker.Item label="Parent" value="Parent" />
                  <Picker.Item label="Psychiatrist" value="Psychiatrist" />
                  <Picker.Item label="NA" value="NA" />
                </Picker>