我无法用cropperjs 裁剪图像答案

【问题标题】：I can't crop images round with cropperjs我无法用cropperjs 裁剪图像
【发布时间】：2020-10-16 05:08:06
【问题描述】：

我使用cropperjs 裁剪图像。但是在裁剪图像后，它们变成了矩形而不是圆形。我怎样才能把它剪成一个圆形？ Bir de resimleri yuvarlak halde nasıl kırpabilirim?

 var cropper = $("#canvas1").cropper({
                    aspectRatio: 1 / 1,
                    cropBoxMovable: false,
                    cropBoxResizable: false,
                    center: true,
                    minContainerWidth: 200,
                    minContainerHeight: 100
                })

 .cropper-crop-box, .cropper-view-box {
            border-radius: 50%;
        }

        .cropper-view-box {
            box-shadow: 0 0 0 1px #39f;
            outline: 0;
        }

【问题讨论】：

没有圆形的图片，显示图片的时候重新应用半径就可以了
那我该怎么做呢？

标签： javascript cropperjs

【解决方案1】：

将注意力集中在以下getRoundedCanvas() 函数上，这是解决您问题的方法：

HTML

<link href="https://maxcdn.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css" rel="stylesheet" />

<link href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta/css/bootstrap.min.css" rel="stylesheet" />

<link href="https://cdnjs.cloudflare.com/ajax/libs/cropperjs/1.1.3/cropper.css" rel="stylesheet" />

<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>
</head>

<body>
   <div class="container">
      <h1>Crop Round Image</h1>
      <h3>Image</h3>
      <div>
      <img id="image" src="https://p1.pxfuel.com/preview/274/652/884/flag-marine-turkey.jpg" alt="Picture">
   </div>
   <h5>Image Source:</h5>
   <p>https://p1.pxfuel.com/preview/274/652/884/flag-marine-turkey.jpg</p>
   <h3>Result</h3>
   <p>
      <button type="button" id="button">Crop</button>
   </p>
   <div id="result"></div>
</div>
</body>

<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta/js/bootstrap.min.js"></script>

<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.11.0/umd/popper.min.js"></script>

<script src="https://github.com/fengyuanchen/cropperjs/blob/master/docs/js/cropper.js"></script>

</html>

CSS

.container {
 margin: 20px auto;
 max-width: 640px;
}

img {
 max-width: 100%;
}

.cropper-view-box,
.cropper-face {
 border-radius: 50%;
}

function getRoundedCanvas(sourceCanvas) {
 var canvas = document.createElement('canvas');
 var context = canvas.getContext('2d');
 var width = sourceCanvas.width;
 var height = sourceCanvas.height;
 
 canvas.width = width;
 canvas.height = height;
 context.imageSmoothingEnabled = true;
 context.drawImage(sourceCanvas, 0, 0, width, height);
 context.globalCompositeOperation = 'destination-in';
 context.beginPath();
 context.arc(width / 2, height / 2, Math.min(width, height) / 2, 0, 2 * Math.PI, true);
 context.fill();
 return canvas;
}

window.addEventListener('DOMContentLoaded', function() {
 var image = document.getElementById('image');
 var button = document.getElementById('button');
 var result = document.getElementById('result');
 var croppable = false;
 var cropper = new Cropper(image, {
  aspectRatio: 1,
  viewMode: 1,
   ready: function() {
   croppable = true;
 },
 });

 button.onclick = function() {
  var croppedCanvas;
  var roundedCanvas;
  var roundedImage;

  if (!croppable) {
   return;
  }

  // Crop
  croppedCanvas = cropper.getCroppedCanvas();

  // Round
  roundedCanvas = getRoundedCanvas(croppedCanvas);

  // Show
  roundedImage = document.createElement('img');
  roundedImage.src = roundedCanvas.toDataURL()
  result.innerHTML = '';
  result.appendChild(roundedImage);
  };
});

Example 以上在 JsFiddle 中。

【讨论】：