在上传之前需要一些帮助来调整图片大小。
我正在使用一个非常出色的解决方案，当它在网站上运行时效果很好，但是第二个我的手机试图从图库或相机上传它会严重挤压图像。
HTML
<!DOCTYPE HTML>
<html>
<head>
<title>Upload Photos</title>
<link rel="stylesheet" href="./style.css" />
<head>
<body>
<h1>Upload Photos</h1>
<form enctype="multipart/form-data">
<input type="file" accept="image/*" />
<div class="photos">
</div>
</form>
<script src="./upload.js"></script>
</body>
</html>
的Javascript
// Once files have been selected
document.querySelector('form input[type=file]').addEventListener('change', function(event){
// Read files
var files = event.target.files;
// Iterate through files
for (var i = 0; i < files.length; i++) {
// Ensure it's an image
if (files[i].type.match(/image.*/)) {
// Load image
var reader = new FileReader();
reader.onload = function (readerEvent) {
var image = new Image();
image.onload = function (imageEvent) {
// Add elemnt to page
var imageElement = document.createElement('div');
imageElement.classList.add('uploading');
imageElement.innerHTML = '<span class="progress"><span></span></span>';
var progressElement = imageElement.querySelector('span.progress span');
progressElement.style.width = 0;
document.querySelector('form div.photos').appendChild(imageElement);
// Resize image
var canvas = document.createElement('canvas'),
max_size = 1200,
width = image.width,
height = image.height;
if (width > height) {
if (width > max_size) {
height *= max_size / width;
width = max_size;
}
} else {
if (height > max_size) {
width *= max_size / height;
height = max_size;
}
}
canvas.width = width;
canvas.height = height;
canvas.getContext('2d').drawImage(image, 0, 0, width, height);
// Upload image
var xhr = new XMLHttpRequest();
if (xhr.upload) {
// Update progress
xhr.upload.addEventListener('progress', function(event) {
var percent = parseInt(event.loaded / event.total * 100);
progressElement.style.width = percent+'%';
}, false);
// File uploaded / failed
xhr.onreadystatechange = function(event) {
if (xhr.readyState == 4) {
if (xhr.status == 200) {
imageElement.classList.remove('uploading');
imageElement.classList.add('uploaded');
imageElement.style.backgroundImage = 'url('+xhr.responseText+')';
console.log('Image uploaded: '+xhr.responseText);
} else {
imageElement.parentNode.removeChild(imageElement);
}
}
}
// Start upload
xhr.open('post', 'process.php', true);
xhr.send(canvas.toDataURL('image/jpeg'));
}
}
image.src = readerEvent.target.result;
}
reader.readAsDataURL(files[i]);
}
}
// Clear files
event.target.value = '';
});
PHP
<?php
// Generate filename
$filename = md5(mt_rand()).'.jpg';
// Read RAW data
$data = file_get_contents('php://input');
// Read string as an image file
$image = file_get_contents('data://'.substr($data, 5));
// Save to disk
if ( ! file_put_contents('images/'.$filename, $image)) {
header('HTTP/1.1 503 Service Unavailable');
exit();
}
// Clean up memory
unset($data);
unset($image);
// Return file URL
echo './images/'.$filename;
?>
任何有助于了解移动电话图像无法正常工作的帮助将不胜感激。