為什么innerHTML無法通過AJAX在響應文本中使用HTML元素？

Question

注意：請不要標記此問題[重復]

我正在嘗試在我的網站上使用php動態創建Blog帖子。 問題是，當瀏覽器收到響應時，無法使用'innerHTML'將blogPosts放在我網站上的Tag部分中。

這是我的HTML代碼：

<section id="contentSection">
</section>
    <button name="LOAD_MORE_REQUEST" id="LoadMoreButton" onclick="loadContent();" value="loadMoreButton">Load more</button>

CSS代碼：

#contentSection{
                height: 1000px;
                width: 100%;
                background-color: white;
                overflow: scroll;
            }

            .ArticleSection1{
                height: 450px;
                width: 48%;
                float: left;
                margin-left: 1.3%;
                margin-bottom: 30px;
                box-shadow: 0px 0px 10px 4px rgb(180, 180, 180);
            }
            .imageDivArticleSection1{
                height: 50%;
                width: 100%;
                overflow: auto;
            }
            .PreviewTextDiv{
                height: 50%;
                width: 100%;
                overflow: auto;
                background-color: rgba(255, 255, 255, 0.904);
            }
            .ArticleSection1 > div > h1{
                padding-left: 2%;
                padding-top: 15px;
                font-size: 28px;
                float: left;
                font-weight: 100;
                display: table-cell;
                font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            }
            .PreviewTextDiv{
                padding-left: 2%;
                padding-top: 15px;
                font-size: 16px;
                float: left;
                font-weight: 100;
                display: table-cell;
                font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            }
            .ArticleSection1 > div > button{
                width: 20%;
                height: 40px;
                font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
                font-weight: 100;
                color: black;
                font-size: 16px;
                border: 1px solid deepskyblue;
                background-color: transparent;
                margin-left: 2%;
                margin-top: 20px;
            }

JS代碼：

var loadMoreButton = document.getElementById("LoadMoreButton").value;
    var sendLoadContentRequest = new XMLHttpRequest();
    requestQuery_Data = new FormData();
    requestQuery_Data.append("LOAD_MORE_REQUEST", loadMoreButton);
    sendLoadContentRequest.open("POST", "LoadContent.php", true);
    sendLoadContentRequest.send(requestQuery_Data);
    DefaultText = document.getElementById("contentSection").innerHTML;
    response = sendLoadContentRequest.responseText;
    document.getElementsByTagName("contentSection").innerHTML = DefaultText +  response;

和PHP代碼：

<?php
if(isset($_POST["LOAD_MORE_REQUEST"])){
    loadContentOnPage();
}
else{
    echo("Error");
}


function loadContentOnPage(){
    $response = '
    <section class="ArticleSection1">
    <div class="imageDivArticleSection1"></div>
    <div class="PreviewTextDiv">
        <h1>Code editors to use</h1>
        <br>
        <p>
                Though this is the era of visual presentations than the text or articles but even after that many blog-
                -ers and bloging engines use text teditors but if you are and coding your own blogging website you
                may also need to put one on your website though there are many prewritten texteditors are avilable 
        </p>
        <button>Read more</button>
    </div>
</section>
    ';

    for($a = 0; $a < 4; $a++){
        echo($response); 
    }
}

?>

我正在嘗試從過去2天開始解決此問題，並且在瀏覽了大多數問題后才發現“區分大小寫”錯誤。

Answer 1

就像@Patrick Evans提到的那樣，您使用的是異步方法，到您的innerHTML行到達時，請求尚未完成

var loadMoreButton = document.getElementById("LoadMoreButton").value;
    var sendLoadContentRequest = new XMLHttpRequest();
    requestQuery_Data = new FormData();
    requestQuery_Data.append("LOAD_MORE_REQUEST", loadMoreButton);
    sendLoadContentRequest.open("POST", "LoadContent.php", true);
    sendLoadContentRequest.send(requestQuery_Data);
    DefaultText = document.getElementById("contentSection").innerHTML;

    sendLoadContentRequest.onreadystatechange = function() {
    if (this.readyState == 4 && this.status == 200) {
      document.getElementById("contentSection").innerHTML = DefaultText +  responseText;
       }
    };