Javascript 表单提交后保持选定的值
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Keep values selected after form submission
提问by eozzy
Consider:
考虑：
<form method="get" action="">
<select name="name">
<option value="a">a</option>
<option value="b">b</option>
</select>
<select name="location">
<option value="x">x</option>
<option value="y">y</option>
</select>
<input type="submit" value="Submit" class="submit" />
</form>
On submitting the form, how do I make sure that the selected values remain selected in the dropdowns? This form is inside WordPress (PHP).
提交表单时，如何确保所选值在下拉列表中保持选中状态？此表单位于 WordPress (PHP) 中。
回答by Sarfraz
To avoid many if-else structures, let JavaScript do the trick automatically:
为了避免许多 if-else 结构，让 JavaScript 自动完成：
<select name="name" id="name">
<option value="a">a</option>
<option value="b">b</option>
</select>
<script type="text/javascript">
document.getElementById('name').value = "<?php echo $_GET['name'];?>";
</script>
<select name="location" id="location">
<option value="x">x</option>
<option value="y">y</option>
</select>
<script type="text/javascript">
document.getElementById('location').value = "<?php echo $_GET['location'];?>";
</script>
回答by Ignacio Vazquez-Abrams
<select name="name">
<option <?php if ($_GET['name'] == 'a') { ?>selected="true" <?php }; ?>value="a">a</option>
<option <?php if ($_GET['name'] == 'b') { ?>selected="true" <?php }; ?>value="b">b</option>
</select>
回答by Ignacio Vazquez-Abrams
After trying all these "solutions", nothing work. I did some research on W3Schoolsbefore and remember there was explanation of keeping values about radio.
在尝试了所有这些“解决方案”之后，没有任何效果。我之前对W3Schools做了一些研究，记得有关于保持广播价值观的解释。
But it also works for the Selectoption. See below for an example. Just try it out and play with it.
但它也适用于该Select选项。请参阅下面的示例。试试吧，玩玩吧。
<?php
$example = $_POST["example"];
?>
<form method="post">
<select name="example">
<option <?php if (isset($example) && $example=="a") echo "selected";?>>a</option>
<option <?php if (isset($example) && $example=="b") echo "selected";?>>b</option>
<option <?php if (isset($example) && $example=="c") echo "selected";?>>c</option>
</select>
<input type="submit" name="submit" value="submit" />
</form>
回答by Kalpesh Prajapati
If you are using WordPress (as is the case with the OP), you can use the selectedfunction.
如果您使用的是 WordPress（就像 OP 一样），您可以使用该selected功能。
<form method="get" action="">
<select name="name">
<option value="a" <?php selected( isset($_POST['name']) ? $_POST['name'] : '', 'a' ); ?>>a</option>
<option value="b" <?php selected( isset($_POST['name']) ? $_POST['name'] : '', 'b' ); ?>>b</option>
</select>
<select name="location">
<option value="x" <?php selected( isset($_POST['location']) ? $_POST['location'] : '', 'x' ); ?>>x</option>
<option value="y" <?php selected( isset($_POST['location']) ? $_POST['location'] : '', 'y' ); ?>>y</option>
</select>
<input type="submit" value="Submit" class="submit" />
</form>
回答by oda
Since WordPress already uses jQuery you can try something like this:
由于 WordPress 已经使用 jQuery，您可以尝试以下操作：
var POST=<?php echo json_encode($_POST); ?>;
for(k in POST){
$("#"+k).val(POST[k]);
}
回答by Lukas Ignatavi?ius
JavaScript only solution:
仅 JavaScript 解决方案：
var tmpParams = decodeURIComponent(window.location.search.substr(1)).split("&");
for (var i = 0; i < tmpParams.length; i++) {
var tmparr = tmpParams[i].split("=");
var tmp = document.getElementsByName(tmparr[0])[0];
if (!!tmp){
document.getElementsByName(tmparr[0])[0].value = tmparr[1];
}
}
Or if you are using jQuery you can replace
或者，如果您使用的是 jQuery，则可以替换
var tmp = document.getElementsByName(tmparr[0])[0];
if (!!tmp){
document.getElementsByName(tmparr[0])[0].value = tmparr[1];
}
with:
和：
$('*[name="'+tmparr[0]+'"]').val(tmparr[1]);
回答by Heena Patel
Try this solution for keep selected value in dropdown:
尝试此解决方案以在下拉列表中保留所选值：
<form action="<?php echo get_page_link(); ?>" method="post">
<select name="<?php echo $field_key['key']; ?>" onchange="javascript:
submit()">
<option value="">All Category</option>
<?php
foreach( $field['choices'] as $key => $value ){
if($post_key==$key){ ?>
<option value="<?php echo $key; ?>" selected><?php echo $value; ?></option>
<?php
}else{?>
<option value="<?php echo $key; ?>"><?php echo $value; ?></option>
<?php }
}?>
</select>
</form>
回答by Heena Patel
I don't work in WordPress much, but for forms outside of WordPress, this works well.
我在 WordPress 中工作不多，但对于 WordPress 之外的表单，这很有效。
PHP
PHP
location = ""; // Declare variable
if($_POST) {
if(!$_POST["location"]) {
$error .= "Location is required.<br />"; // If not selected, add string to error message
}else{
$location = $_POST["location"]; // If selected, assign to variable
}
HTML
HTML
<select name="location">
<option value="0">Choose...</option>
<option value="1" <?php if (isset($location) && $location == "1") echo "selected" ?>>location 1</option>
<option value="2" <?php if (isset($location) && $location == "2") echo "selected" ?>>location 2</option>
</select>
回答by lawrghita
Just change this line:
只需更改这一行：
<input type="submit" value="Submit" class="submit" />
with this line:
用这一行：
<input type="submit" value="Submit/Reload" class="submit" onclick="history.go(-1);">
回答by TonyTee
This works for me!
这对我有用！
<label for="reason">Reason:</label>
<select name="reason" size="1" id="name" >
<option value="NG" selected="SELECTED"><?php if (!(strcmp("NG", $_POST["reason"]))) {echo "selected=\"selected\"";} ?>Selection a reason below</option>
<option value="General"<?php if (!(strcmp("General", $_POST["reason"]))) {echo "selected=\"selected\"";} ?>>General Question</option>
<option value="Account"<?php if (!(strcmp("Account", $_POST["reason"]))) {echo "selected=\"selected\"";} ?>>Account Question</option>
<option value="Other"<?php if (!(strcmp("Other", $_POST["reason"]))) {echo "selected=\"selected\"";} ?>>Other</option>
</select>
