小编pho*_*ong的帖子

如何在 React Native 中调用当前组件中的其他组件函数？它们也都使用不同的脚本。

任何人都知道如何在本机反应中做到这一点？

//ClassOne.js
class ClassOne extends React.Component {

    constructor(props) {
        super(props);
    }

    setValue(){
    }
}

//ClassTwo.js
class ClassTwo extends React.Component {

    constructor(props) {
        super(props);   
    }

    callSetValue(){
        ClassOne.setValue(); HOW???
    }
}

如何使Bootstrap 4卡成为按钮。这意味着我单击卡中的任何部分都会调用某些操作。

这段代码来自bootstrap 4

<div class="card-deck-wrapper">
  <div class="card-deck">
    <div class="card">
      <img class="card-img-top" data-src="..." alt="Card image cap">
      <div class="card-block">
        <h4 class="card-title">Card title</h4>
        <p class="card-text">This is a longer card with supporting text below as a natural lead-in to additional content. This content is a little bit longer.</p>
        <p class="card-text"><small class="text-muted">Last updated 3 mins ago</small></p>
      </div>
    </div>
    <div class="card">
      <img class="card-img-top" data-src="..." alt="Card image cap">
      <div class="card-block">
        <h4 class="card-title">Card title</h4>
        <p class="card-text">This card has supporting text below as a natural lead-in to additional …

我不确定是什么阻止我在 firebase 上部署 它阻止我部署到 firebase 功能。

firebase deploy --only functions\n

谁能帮我看看问题出在哪里

  174:75  warning  Unexpected function expression      prefer-arrow-callback\n  190:28  warning  Unexpected function expression      prefer-arrow-callback\n  196:34  warning  Unexpected function expression      prefer-arrow-callback\n  239:36  warning  Unexpected function expression      prefer-arrow-callback\n  291:86  warning  Unexpected function expression      prefer-arrow-callback\n  297:26  warning  Unexpected function expression      prefer-arrow-callback\n  317:43  warning  Unexpected function expression      prefer-arrow-callback\n  378:31  warning  Don't make functions within a loop  no-loop-func\n  477:31  warning  Don't make functions within a loop  no-loop-func\n\n\xe2\x9c\x96 9 problems (0 errors, 9 warnings)\n …

如何使外部textinput背景透明，使其看起来像在地图内部，而不是在顶部？提前致谢！

<View style={styles.container}>
    <TextInput style={styles.input}/>
    <MapView style={styles.map}/>
</View>

var styles = StyleSheet.create ({
    container: {
        flex: 1,
        justifyContent: 'center',
        backgroundColor: '#F5FCFF',
    },
    map: {
        flex: 1,
    },
    input: {
        height: 36,
        padding: 10,
        margin: 18,
        fontSize: 18,
        borderWidth: 1,
        borderRadius: 10,
        borderColor: '#48BBEC',
        backgroundColor: 'rgba(0,0,0,0)',
    }
})

如何对 Firebase.functions().httpsCallable 执行 GET？我不断收到 POST 错误 404，但这是对我的服务器的 GET 请求。我应该不传递任何内容，还是需要更改此 httpsCallable 来获取函数？

客户

let updateWorkshop = Firebase.functions().httpsCallable('api/update/workshop');

    updateWorkshop({/* nothing */})
      .then(res => {
        console.log(res);

      }, err => {
        console.log(err);

      })

服务器

app.get('/v3/update/workshop', asyncMiddleware( async (req, res, next) => {
    let results = await UPDATE_WORKSHOP_DATE.Run()
    res.status(200).json({results: results})
}))

exports.api = FUNCTIONS.https.onRequest(app);

为什么我不能在 floatActionButton 中使用 showModalBottomSheet？它只是不断向我显示此错误：

I/flutter (16368): ??? EXCEPTION CAUGHT BY GESTURE ????????????????????????????????????????????????????????????????????
I/flutter (16368): The following assertion was thrown while handling a gesture:
I/flutter (16368): No MediaQuery widget found.
I/flutter (16368): MyApp widgets require a MediaQuery widget ancestor.
I/flutter (16368): The specific widget that could not find a MediaQuery ancestor was:
I/flutter (16368):   MyApp
I/flutter (16368): The ownership chain for the affected widget is: "MyApp ? [root]"
I/flutter (16368): Typically, the MediaQuery widget is introduced by the MaterialApp or WidgetsApp …

如何禁用反应选择上的输入？那可能吗？我只是希望它是一个下拉菜单

<Select
    placeholder="Action"
    className="col-3 mt-3"
    value={orderStatusInput}
    onChange={this.onOrderStatusChange}
    options={orderStatusOptions}
/>

我正在使用react-native.如何在iOS地图上获取中心坐标？

当我将onSuccessCreateClass添加到meteor.call回调中时，出现此错误。不知道这是怎么回事？

传递调用'createClass'的结果时发生异常：TypeError：this.onSuccessCreateClass不是http：// localhost：3000 / app / client / components / MyClasses.jsx？044c7b228d4b33fcea4b9f3c05da6d82e5e6c8b7：37：11 处的函数。_callback（http： //localhost:3000/packages/meteor.js?9730f4ff059088b3f7f14c0672d155218a1802d4:999:22）在_.extend._maybeInvokeCallback（HTTP：//本地主机：3000 /包/ DDP-client.js 250b63e6c919c5383a0511ee4efbf42bb70a650f：3500：12）在.extend .dataVisible（http：// localhost：3000 / packages / ddp-client.js？250b63e6c919c5383a0511ee4efbf42bb70a650f：3529：10）at http：// localhost：3000 / packages / ddp-client.js？250b63e6c919c5383a0511ee4efbf42bb707650：4365 在Array.forEach（本机）在功能处。.each ._。forEach（HTTP：//本地主机：3000 /包/ underscore.js 46eaedbdeb6e71c82af1b16f51c7da4127d6f285：149：11在_.extend._runAfterUpdateCallbacks）（HTTP：//本地主机：3000 /包/ DDP-client.js 250b63e6c919c5383a0511ee4efbf42bb70a650f：4364：7）在_.extend._livedata_data（http：// localhost：3000 / packages / ddp-client.js？250b63e6c919c5383a0511ee4efbf42bb70a650f：4354：10）位于onMessage（http：// localhost：3000 / packages / ddp-client.js？250b63e6c919c5383a0511ee4ef6503 ：12）

onSuccessCreateClass() {
    console.log("Successfully created New Class")
    $("#createClassModal").modal('hide')
    $('#createClassModal').on('hidden.bs.modal', function () {
        $(this).find('form').trigger('reset')
    })
},

onPressSubmit(e) { …

如何查询多个 whereArgs？我总是返回 1 行。它应该返回 3 行。

final res = await db.query(
  Constants.dbTable, 
  where: "name = ?",
  whereArgs: ['read', "uio", 'go'],  
);