onValueChange 函数型
selectedValue 任意类型
'use strict';
var react = require('react-native');
var {
PickerIOS,
Text,
View,
} = React;
var PickerItemIOS = PickerIOS.Item;
var CAR_MAKES_AND_MODELS = {
amc: {
name: 'AMC',
models: ['AMX', 'Concord', 'Eagle', 'Gremlin', 'Matador', 'Pacer'],
},
alfa: {
name: 'Alfa-Romeo',
models: ['159', '4C', 'Alfasud', 'Brera', 'GTV6', 'Giulia', 'MiTo', 'Spider'],
},
aston: {
name: 'Aston Martin',
models: ['DB5', 'DB9', 'DBS', 'Rapide', 'Vanquish', 'Vantage'],
},
audi: {
name: 'Audi',
models: ['90', '4000', '5000', 'A3', 'A4', 'A5', 'A6', 'A7', 'A8', 'Q5', 'Q7'],
},
austin: {
name: 'Austin',
models: ['America', 'Maestro', 'Maxi', 'Mini', 'Montego', 'Princess'],
},
borgward: {
name: 'Borgward',
models: ['Hansa', 'Isabella', 'P100'],
},
buick: {
name: 'Buick',
models: ['Electra', 'LaCrosse', 'LeSabre', 'Park Avenue', 'Regal',
'Roadmaster', 'Skylark'],
},
cadillac: {
name: 'Cadillac',
models: ['Catera', 'Cimarron', 'Eldorado', 'Fleetwood', 'Sedan de Ville'],
},
chevrolet: {
name: 'Chevrolet',
models: ['Astro', 'Aveo', 'Bel Air', 'Captiva', 'Cavalier', 'Chevelle',
'Corvair', 'Corvette', 'Cruze', 'Nova', 'SS', 'Vega', 'Volt'],
},
};
var PickerExample = React.createClass({
getInitialState: function() {
return {
carMake: 'cadillac',
modelIndex: 3,
};
},
render: function() {
var make = CAR_MAKES_AND_MODELS[this.state.carMake];
var selectionString = make.name + ' ' + make.models[this.state.modelIndex];
return (
<View>
<Text>Please choose a make for your car:</Text>
<PickerIOS
selectedValue={this.state.carMake}
onValueChange={(carMake) => this.setState({carMake, modelIndex: 0})}>
{Object.keys(CAR_MAKES_AND_MODELS).map((carMake) => (
<PickerItemIOS
key={carMake}
value={carMake}
label={CAR_MAKES_AND_MODELS[carMake].name}
/>
)
)}
</PickerIOS>
<Text>Please choose a model of {make.name}:</Text>
<PickerIOS
selectedValue={this.state.modelIndex}
key={this.state.carMake}
onValueChange={(modelIndex) => this.setState({modelIndex})}>
{CAR_MAKES_AND_MODELS[this.state.carMake].models.map(
(modelName, modelIndex) => (
<PickerItemIOS
key={this.state.carmake + '_' + modelIndex}
value={modelIndex}
label={modelName}
/>
))
}
</PickerIOS>
<Text>You selected: {selectionString}</Text>
</View>
);
},
});
exports.title = '<PickerIOS>';
exports.description = 'Render lists of selectable options with UIPickerView.';
exports.examples = [
{
title: '<PickerIOS>',
render: function(): ReactElement {
return <PickerExample />;
},
}];