javascript - 所有事件的本地存储

Question

   function pushButton(buttonValue) {
    if (buttonValue == 'C') {
        document.getElementById('screen').value = '0';
    }
    else {//this is where most changes occured
        var x= document.getElementById('screen').value 
        x =parseInt(x)+ parseInt(buttonValue);
        document.getElementById('screen').value=x;
        localStorage.setItem('answer', x);
    }
}

    function calculate(equation) {
        var answer = eval(equation);
        document.getElementById('screen').value = answer;
    }

HTML:

    <table class="calc" cellpadding=2> 
        <td><input type="button" class="calc" id="screen" value="0" ></td>
        <tr>
    </table>
    <table class="calc" cellpadding=2> 
        <td><button type="button" onclick="pushButton(1)" value="Call2Functions">1</td>
        <td><button type="button" onclick="pushButton(2)" value="Call2Functions">2</td>
        <td><button type="button" onclick="pushButton(3)" value="Call2Functions">3</td>
        <td></td>
    </tr>
    <div>

即使在尝试此代码后，我也无法在本地存储值。请问有人可以帮助我吗？我仍然在寻找这个问题的解决方案..添加 localStorage 后我也无法在本地存储值 请帮助我，我已经尝试了很多...

Answer 1

要将项目存储在 localStorage 中，您需要使用 localStorage.setItem 存储与键配对的值:

var key = 'yourKey'
,   resultToStore = 'test';
localStorage.setItem(key, resultToStore);

要检索值，只需调用 localStorage.getItem 并传入 key 即可:

var returnedResult = localStorage.getItem(key);

在您的函数 pushButton 中，您需要存储该值:

function pushButton(buttonValue) {
    if (buttonValue == 'C') {
        document.getElementById('screen').value = '0';
    }
    else {//this is where most changes occured
        var x= document.getElementById('screen').value 
        x =parseInt(x)+ parseInt(buttonValue);
        document.getElementById('screen').value=x;
        localStorage.setItem('answer', x);
    }
}

现在，每当页面加载时，您都需要查看 localStorage 中是否有值，如果存在则获取该值:

window.onload = function() {
    var oldAnswer = localStorage.getItem('answer');
    if(oldAnswer) {
        document.getElementById('screen').value = oldAnswer;
    }
}