Daniil's questions

我正在尝试添加一个自定义图标，但它不起作用，它只是没有显示在屏幕上。告诉我我的错误是什么以及如何解决？

我的配置-

class CustomIcons {
  CustomIcons._();

  static const _kFontFam = 'MyFlutterApp';
  static const String? _kFontPkg = null;

  static const IconData airline_seat_recline_normal = IconData(0xe800, fontFamily: _kFontFam, fontPackage: _kFontPkg);
  static const IconData map_marker = IconData(0xe833, fontFamily: _kFontFam, fontPackage: _kFontPkg);
  static const IconData sliders = IconData(0xf1de, fontFamily: _kFontFam, fontPackage: _kFontPkg);
}

pubsec.yamal-

- family: CustomIcons
       fonts:
         - asset: fonts/Icon-Place.ttf

我这样使用- Icon(CustomIcons.sliders)

请告诉我，我需要在我的应用程序中单击按钮时向信使发送一条带有信息的消息（W / a，电报（其中任何一个））。有没有为此设计的包？或任何其他解决方案？

在细节。用户将产品添加到购物车，进入购物车，输入他的号码，然后......所有商品（其名称）和号码应发送给任何信使

大家好，我是根据网上的一篇文章写的，里面讲了如何添加和读取本地存储（shared_preferences）。所以，有一个添加和读取数据的文件，它看起来像这样 -

static saveData<T>(String key, T value) async {
    SharedPreferences prefs = await SharedPreferences.getInstance();

    switch (T) {
      case String:
        prefs.setString(key, value as String);
        break;
      case int:
        prefs.setInt(key, value as int);
        break;
      case bool:
        prefs.setBool(key, value as bool);
        break;
      // case stringList:
      //   prefs.setStringList(key, <String>[] as stringList);
      //   break;
      case double:
        prefs.setDouble(key, value as double);
        break;
    }

请告诉我如何在此处添加此方法-await prefs.setStringList('items', <String>['Earth', 'Moon', 'Sun']);

还有，如何实现删除？这是我的尝试-

static Future<T> removeData<T>(String key) async {
    SharedPreferences prefs = await SharedPreferences.getInstance();
      return prefs.remove(key) as T;
  }

大家好，我写了一个小flutter应用程序，在模拟器中一切正常，但是当我在手机上运行它时，我无法登录（授权），并且它不会抛出错误，据我了解，请求没有被愚蠢地发送，我该怎么办？

有一个数组，其中记录了计算器上的所有点击。进一步，这个数组在页面上显示为字符串，即=5+5=10可以显示在历史中（第一个乘号，不应该是，连续的符号，也不应该是）。如何进行例外处理，以便并非所有内容都被推入数组？

    const calculator = {
    displayValue: '0',
    firstOperand: null,
    waitingForSecondOperand: false,
    operator: null,
    expressionData: [],
    historyData: [],
};

function inputDigit(digit) {
    const {
        displayValue,
        waitingForSecondOperand
    } = calculator;

    if (waitingForSecondOperand === true) {
        calculator.displayValue = digit;
        calculator.waitingForSecondOperand = false;
    } else {
        calculator.displayValue = displayValue === '0' ? digit : displayValue + digit;
    }
    calculator.expressionData.push(digit);
}

function inputDecimal(dot) {
    // If the `displayValue` does not contain a decimal point
    if (!calculator.displayValue.includes(dot)) {
        // Append the decimal point
        calculator.displayValue += dot;
        calculator.expressionData.push(dot);
    }
}

function handleOperator(nextOperator) {
    calculator.expressionData.push(nextOperator);
    const {
        firstOperand,
        displayValue,
        operator
    } = calculator
    const inputValue = parseFloat(displayValue);

    if (operator && calculator.waitingForSecondOperand) {
        calculator.operator = nextOperator;
        return;
    }

    if (firstOperand == null) {
        calculator.firstOperand = inputValue;
    } else if (operator) {
        const currentValue = firstOperand || 0;
        const result = performCalculation[operator](currentValue, inputValue);

        calculator.displayValue = String(result);
        calculator.firstOperand = result;
        calculator.expressionData.push(result);
        calculator.historyData.push({expression: calculator.expressionData.join('')});
        calculator.expressionData = [];
        resultation();
    }

    calculator.waitingForSecondOperand = true;
    calculator.operator = nextOperator;
}
function resultation () {
    let resulstHistory = document.getElementById('results');
    let string = '';
    for (let key in calculator.historyData) {
        string += '' + calculator.historyData[key]['expression'] + "<br>";
        console.log(calculator.historyData[key]['expression'])
    };
    resulstHistory.innerHTML = string

}
const performCalculation = {
    '/': (firstOperand, secondOperand) => firstOperand / secondOperand,

    '*': (firstOperand, secondOperand) => firstOperand * secondOperand,

    '+': (firstOperand, secondOperand) => firstOperand + secondOperand,

    '-': (firstOperand, secondOperand) => firstOperand - secondOperand,

    '=': (firstOperand, secondOperand) => secondOperand
};

function resetCalculator() {
    calculator.displayValue = '0';
    calculator.firstOperand = null;
    calculator.waitingForSecondOperand = false;
    calculator.operator = null;
}

function updateDisplay() {
    const display = document.querySelector('.calculator-screen');
    display.value = calculator.displayValue;
}

updateDisplay();


const keys = document.querySelector('.calculator-keys');
keys.addEventListener('click', (event) => {
    const {
        target
    } = event;
    if (!target.matches('button')) {
        return;
    }

    if (target.classList.contains('operator')) {

        handleOperator(target.value);
        updateDisplay();
        return;
    }

    if (target.classList.contains('decimal')) {
        inputDecimal(target.value);
        updateDisplay();
        return;
    }

    if (target.classList.contains('all-clear')) {
        resetCalculator();
        updateDisplay();
        return;
    }

    inputDigit(target.value);
    updateDisplay();
});

有一个带有照片的块，照片被放大，但其中的跨度不是。我什至为跨度设置了相同的类和 id，但它仍然不起作用（<a><img><span></a> --- 这就是结构的样子）。

.column#zoomIn img {
  -webkit-transform: scale(1);
  transform: scale(1);
  -webkit-transition: .3s ease-in-out;
  transition: .3s ease-in-out;
}

.column#zoomIn:hover img {
  -webkit-transform: scale(1.3);
  transform: scale(1.3);
}

<div class="flex mt-5">
  <a href="" class="column" id="zoomIn">
    <img src="./img/IMG_5345.JPG" alt="" class="w-56 border-2 border-gray-200"">
    <span id="zoomIn" class="column text-gray-500 bg-white px-4 py-2">В наличии:<span class="text-black"> 10</span></span>
  </a>
  <a href="" class="column" id="zoomIn">
    <img src="./img/IMG_5346.JPG" alt="" class="w-56 ml-7 border-2 border-gray-200"">
    <span id="zoomIn" class="column text-gray-500 inline-block ml-7 bg-white px-4 py-2">В наличии:<span class="text-black"> 10</span></span>
  </a>
  <a href="" class="column" id="zoomIn">
    <img src="./img/IMG_5347.JPG" alt="" class="w-56 ml-7 border-2 border-gray-200"">
    <span class="text-gray-500 inline-block ml-7">В наличии:<span class="text-black"> 10</span></span>
  </a>
  <a href="" class="column" id="zoomIn">
    <img src="./img/IMG_5340.JPG" alt="" class="w-56 ml-7 border-2 border-gray-200"">
    <span class="text-gray-500 inline-block ml-7">В наличии:<span class="text-black"> 10</span></span>
  </a>
</div>