xmlhttprequest onload无法正常工作

Question

我尝试通过javascript和xmlhttprequest验证表单，但它无法正常工作。 我的onload功能应该弹出一个警报，有时它会工作，警报会弹出，有时不会。我真的不明白我的错误。

document.getElementById("button").addEventListener("click", function(){
  validateForm(document.myForm);
});


function validateForm(form) {

  if (form.FirstName.value.match(/^([A-Za-z ]+)$/) &&
    form.Surname.value.match(/^([A-Za-z ]+)$/) &&
    form.Verein.value.match(/^([A-Za-z ]+)$/) &&
    form.Headcoach.value.match(/^([A-Za-z ]+)$/) &&
    form.Assistantcoach.value.match(/^([A-Za-z ]+)$/) &&
    form.Rueckennummer.value.match(/^([0-9])$/) &&
    form.Rueckennummer.value > 3 &&
    form.Rueckennummer.value < 16 &&
    (document.getElementById("Aktiv1").checked || document.getElementById("Aktiv2").checked) &&
    (new Date(document.getElementById("idDate").value).getFullYear() <= new Date().getFullYear()) ) {

      senden(form);

  }else{
      alert("Einige Eingaben sind fehlerhaft. Bitte ueberpruefen Sie ihre 
            Eingaben.");
    }

}

function senden(form){
 var formData = new FormData(form);
 var xhr = new XMLHttpRequest();
 xhr.open('POST', 'http://188.166.165.74:13337/api/players', true);
 xhr.responseType = 'json';
 xhr.onload = function() {
  alert("Daten wurden erfolgreich uebermittelt")
 };
 xhr.send(formData);
}

Answer 1

尝试使用 <?php // database connection info $conn = @mysql_connect('localhost','root','') or die(mysql_error()); $db = mysql_select_db('friends',$conn) or die(mysql_error()); // find out how many rows are in the table $sql = "SELECT COUNT(*) FROM user"; $result = mysql_query($sql, $conn) or die(mysql_error()); $r = mysql_fetch_row($result); $numrows = $r[0]; // number of rows to show per page $rowsperpage = 1; // find out total pages $totalpages = ceil($numrows / $rowsperpage); // get the current page or set a default if (isset($_GET['currentpage']) && is_numeric($_GET['currentpage'])) { // cast var as int $currentpage = (int) $_GET['currentpage']; } else { // default page num $currentpage = 1; } // end if // if current page is greater than total pages... if ($currentpage > $totalpages) { // set current page to last page $currentpage = $totalpages; } // end if // if current page is less than first page... if ($currentpage < 1) { // set current page to first page $currentpage = 1; } // end if // the offset of the list, based on current page $offset = ($currentpage - 1) * $rowsperpage; // get the info from the db $sql = "SELECT name, surname, score FROM user LIMIT $offset, $rowsperpage"; $result = mysql_query($sql, $conn) or die(mysql_error()); ?> <TABLE BORDER="3" CELLPADDING="10" CELLSPACING="10"> <TD> <table border="0" cellpadding="4"> <tr> <td bgcolor="#CCCCCC"><strong>Name</strong></td> <td bgcolor="#CCCCCC"><strong>Surname</strong></td> <td bgcolor="#CCCCCC"><strong>score</strong></td> </tr> <?php while($row = mysql_fetch_assoc($result)) { echo "<tr>"; echo "<td>".$row['name']."</td>"; echo "<td>".$row['surname']."</td>"; echo "<td>".$row['score']."</td>"; echo "</tr>"; } ?> </table> <?php /****** build the pagination links ******/ // range of num links to show $range = 1; // if not on page 1, don't show back links if ($currentpage > 1) { // get previous page num $prevpage = $currentpage - 1; // show < link to go back to 1 page echo " <a href='{$_SERVER['PHP_SELF']}?currentpage=$prevpage' class=previous>Previous</a> "; $prev_button = (isset($prev_id) && $prev_id>0)?'<a href="#" data-id="'.$prev_id.'" class="get_pic"><img src="prev.png" border="0" /></a>':''; } // end if // loop to show links to range of pages around current page for ($x = ($currentpage - $range); $x < (($currentpage + $range) + 1); $x++) { // if it's a valid page number... if (($x > 0) && ($x <= $totalpages)) { // if we're on current page... if ($x == $currentpage) { // 'highlight' it but don't make a link echo " [<b>$x</b>] "; // if not current page... } else { // make it a link } // end else } // end if } // end for // if not on last page, show forward and last page links if ($currentpage != $totalpages) { // get next page $nextpage = $currentpage + 1; // echo forward link for next page echo " <a href='{$_SERVER['PHP_SELF']}?currentpage=$nextpage' class=next>next</a> "; // echo forward link for lastpage } // end if /****** end build pagination links ******/ ?> 代替onreadystatechange ...

onload