个人中心
gpt4 book ai didi

javascript - CROPPER JS 获取裁剪 Canvas 不适用于较大的文件

转载 作者：行者123 更新时间：2023-12-02 23:08:43 25 4
gpt4 key购买 nike

我正在使用 https://github.com/fengyuanchen/cropperjs/，但它在 getCroppedCanvas 函数中存在问题，它在小图像上工作得很好，但在较大图像上却无法显示

result.appendChild(cropper.getCroppedCanvas());

我正在使用这个实例 https://fengyuanchen.github.io/cropperjs/examples/upload-cropped-image-to-server.html ；源代码:

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta http-equiv="x-ua-compatible" content="ie=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
  <title>Cropper.js</title>
  <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.2/css/bootstrap.min.css">
  <link rel="stylesheet" href="../css/cropper.css">
  <style>
    .label {
      cursor: pointer;
    }

    .progress {
      display: none;
      margin-bottom: 1rem;
    }

    .alert {
      display: none;
    }

    .img-container img {
      max-width: 100%;
    }
  </style>
</head>
<body>
  <div class="container">
    <h1>Upload cropped image to server</h1>
    <label class="label" data-toggle="tooltip" title="Change your avatar">
      <img class="rounded" id="avatar" src="https://avatars0.githubusercontent.com/u/3456749?s=160" alt="avatar">
      <input type="file" class="sr-only" id="input" name="image" accept="image/*">
    </label>
    <div class="progress">
      <div class="progress-bar progress-bar-striped progress-bar-animated" role="progressbar" aria-valuenow="0" aria-valuemin="0" aria-valuemax="100">0%</div>
    </div>
    <div class="alert" role="alert"></div>
    <div class="modal fade" id="modal" tabindex="-1" role="dialog" aria-labelledby="modalLabel" aria-hidden="true">
      <div class="modal-dialog" role="document">
        <div class="modal-content">
          <div class="modal-header">
            <h5 class="modal-title" id="modalLabel">Crop the image</h5>
            <button type="button" class="close" data-dismiss="modal" aria-label="Close">
              <span aria-hidden="true">&times;</span>
            </button>
          </div>
          <div class="modal-body">
            <div class="img-container">
              <img id="image" src="https://avatars0.githubusercontent.com/u/3456749">
            </div>
          </div>
          <div class="modal-footer">
            <button type="button" class="btn btn-secondary" data-dismiss="modal">Cancel</button>
            <button type="button" class="btn btn-primary" id="crop">Crop</button>
          </div>
        </div>
      </div>
    </div>
  </div>
  <script src="https://code.jquery.com/jquery-3.4.1.min.js"></script>
  <script src="https://stackpath.bootstrapcdn.com/bootstrap/4.1.2/js/bootstrap.bundle.min.js"></script>
  <script src="https://fengyuanchen.github.io/cropperjs/js/cropper.js"></script>
  <script>
    window.addEventListener('DOMContentLoaded', function () {
      var avatar = document.getElementById('avatar');
      var image = document.getElementById('image');
      var input = document.getElementById('input');
      var $progress = $('.progress');
      var $progressBar = $('.progress-bar');
      var $alert = $('.alert');
      var $modal = $('#modal');
      var cropper;

      $('[data-toggle="tooltip"]').tooltip();

      input.addEventListener('change', function (e) {
        var files = e.target.files;
        var done = function (url) {
          input.value = '';
          image.src = url;
          $alert.hide();
          $modal.modal('show');
        };
        var reader;
        var file;
        var url;

        if (files && files.length > 0) {
          file = files[0];

          if (URL) {
            done(URL.createObjectURL(file));
          } else if (FileReader) {
            reader = new FileReader();
            reader.onload = function (e) {
              done(reader.result);
            };
            reader.readAsDataURL(file);
          }
        }
      });

      $modal.on('shown.bs.modal', function () {
        cropper = new Cropper(image, {
          aspectRatio: 1,
          viewMode: 3,
        });
      }).on('hidden.bs.modal', function () {
        cropper.destroy();
        cropper = null;
      });

      document.getElementById('crop').addEventListener('click', function () {
        var initialAvatarURL;
        var canvas;

        $modal.modal('hide');

        if (cropper) {
          canvas = cropper.getCroppedCanvas({
            width: 160,
            height: 160,
          });
          initialAvatarURL = avatar.src;
          avatar.src = canvas.toDataURL();
          $progress.show();
          $alert.removeClass('alert-success alert-warning');
          canvas.toBlob(function (blob) {
            var formData = new FormData();

            formData.append('avatar', blob, 'avatar.jpg');
            $.ajax('https://jsonplaceholder.typicode.com/posts', {
              method: 'POST',
              data: formData,
              processData: false,
              contentType: false,

              xhr: function () {
                var xhr = new XMLHttpRequest();

                xhr.upload.onprogress = function (e) {
                  var percent = '0';
                  var percentage = '0%';

                  if (e.lengthComputable) {
                    percent = Math.round((e.loaded / e.total) * 100);
                    percentage = percent + '%';
                    $progressBar.width(percentage).attr('aria-valuenow', percent).text(percentage);
                  }
                };

                return xhr;
              },

              success: function () {
                $alert.show().addClass('alert-success').text('Upload success');
              },

              error: function () {
                avatar.src = initialAvatarURL;
                $alert.show().addClass('alert-warning').text('Upload error');
              },

              complete: function () {
                $progress.hide();
              },
            });
          });
        }
      });
    });
  </script>
</body>
</html>

cropper脚本位于:https://fengyuanchen.github.io/cropperjs/js/cropper.js

最佳答案

使用croppiejs帮助我解决了这个问题。要使用 Croppie 进行预览，您只需将 html 图像元素的值设置为croppie 的 base64 结果:

首先创建croppie实例:

var cropperlg = new Croppie(document.getElementById('croppie-lg'), {
    viewport: {
        width: 400
        height: 800
    },
    boundary: {
        height: 500
        width: 1000
    }
});

这段代码将croppie绑定(bind)到图像并在单击时执行裁剪。编辑:我简化了代码以获得更基本的示例。

cropperlg.bind({
    url: '/images/someimg.jpg'
});

$('#crop-btn').on('click', (e) => {
    cropperlg.result({
        type: 'canvas',
        size: { width: 1000, height: 400 }
    }).then(function(result) {
        $('#cropped-img').attr('src', result);
    })
});

从这里你应该能够弄清楚。

关于javascript - CROPPER JS 获取裁剪 Canvas 不适用于较大的文件，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/57466144/

25 4 0
文章推荐： javascript - 使用VelocityJS解析VTL时如何修复 "Unexpected token $ in JSON"
文章推荐： javascript - 由于使用 require AND import 导致无服务器部署失败
文章推荐： Javascript 在 Node.js 上下文中访问 ejs 变量
文章推荐： javascript - 如何使用 dom 选择器作为对象中的值来迭代对象，然后使用它们来设置值？
行者123
个人简介

我是一名优秀的程序员,十分优秀！

滴滴打车优惠券免费领取
滴滴打车优惠券
全站热门文章
Copyright 2021 - 2024 cfsdn All Rights Reserved 蜀ICP备2022000587号
广告合作:1813099741@qq.com 6ren.com