尝试使用输入类型文本传递超过 524288 字节的 ToDataURL

2021-12-21 00:00:00 input canvas jquery php todataurl

我正在尝试使用 Canvas 的 DataURL(使用 JavaScript)创建图像.当用户点击提交时，该值会被发送到一个输入类型的文本标签(例如，)，然而，显然在 Chrome 上，当它的长度为 524,288 个字符.

我将它发送到输入标签，因为我需要在 PHP 中获取值(作为 $_POST['dataurltext'];)，以便我可以创建一个图像并将其上传到我的网络服务器.

关于如何绕过这个长度的任何想法?

我应该改用评论框吗?

感谢您的帮助，不胜感激.

解决方案

Try sent canvas as Blob at javascript;使用 fopen() 和 php://input 作为参数来读取 Blob、stream_copy_to_stream 或 file_get_contents() , file_put_contents() 在 php

处处理文件

参见 HTMLCanvasElement.toBlob()

if (!HTMLCanvasElement.prototype.toBlob) {Object.defineProperty(HTMLCanvasElement.prototype, 'toBlob', {价值:功能(回调，类型，质量){var binStr = atob( this.toDataURL(type, quality).split(',')[1] ),len = binStr.length,arr = new Uint8Array(len);for (var i=0; i

除了 $_POST, $_GET和 $_FILE:在 JavaScript 和 PHP 中使用 Blob

I am trying to create an image using DataURL of a Canvas (using JavaScript). When a user hits submit, the value gets sent to an Input type text tag (e.g., <input type='text'>), however, apparently on Chrome, the text gets cut off when it is at length 524,288 characters.



I am sending it to an input tag because I need to obtain the value in PHP (as a $_POST['dataurltext'];), so that I can create an image and upload it to my web server.

Any ideas on how to bypass this length?

Should I use a comment box instead, maybe?

Thank you for any help, it will be greatly appreciated.
 解决方案 Try sending canvas as Blob at javascript; use fopen() with php://input as parameter to read Blob, stream_copy_to_stream or file_get_contents() , file_put_contents() to process file at php

See HTMLCanvasElement.toBlob()
if (!HTMLCanvasElement.prototype.toBlob) {
 Object.defineProperty(HTMLCanvasElement.prototype, 'toBlob', {
  value: function (callback, type, quality) {

    var binStr = atob( this.toDataURL(type, quality).split(',')[1] ),
        len = binStr.length,
        arr = new Uint8Array(len);

    for (var i=0; i<len; i++ ) {
     arr[i] = binStr.charCodeAt(i);
    }

    callback( new Blob( [arr], {type: type || 'image/png'} ) );
  }
 });
}
Beyond $_POST, $_GET and $_FILE: Working with Blob in JavaScript and PHP
<?php

// choose a filename
$filename = "hello.json";

// the Blob will be in the input stream, so we use php://input
$input = fopen('php://input', 'rb');
$file = fopen($filename, 'wb'); 

// Note: we don't need open and stream to stream, we could've used file_get_contents and file_put_contents
stream_copy_to_stream($input, $file);
fclose($input);
fclose($file);

?>


	
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