小编Ask*_*ker的帖子

我有画布.我有油漆工具铅笔和橡皮擦.如何在不用白色覆盖(透支)的情况下擦除图纸.

我的代码橡皮擦用白色绘图:http: //jsfiddle.net/66z12xb0/

我在后端保存图像后绘图.

<?php
$images = scandir(ROOT_FS . FINISH_DRAW_PATH, 1);
$imageData = $GLOBALS['HTTP_RAW_POST_DATA'];
$filteredData = substr($imageData, strpos($imageData, ",") + 1);
$unencodedData = base64_decode($filteredData);

$fileName = "photo.png"; 
$fp = fopen(ROOT_FS .  SAVE_DRAW_PATH . $fileName, 'wb');
fwrite($fp, $unencodedData);
fclose($fp);
?>

使用Windows照片查看器打开并查看此结果:

额外上传照片:

$("#upload_foto").click(function() {
    var data = canvas.toDataURL('image/png'); 
    var ajax = new XMLHttpRequest();
    ajax.open('POST', 'backend.php', false);
    ajax.setRequestHeader('Content-Type', 'application/upload');
    ajax.send(data);
}); 

<button type='button' id='upload_foto'>Upload</button>