javascript - 如何通过CropperJS获取裁剪图像的坐标？

Question

我正在使用cropper JS裁剪我的图像。我可以获得 Canvas 的宽度和高度，但是需要知道裁剪图像的坐标(X 和 Y)。

这是我的代码-

(function () {


  //getting ratio
  function getImageRatio(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.beginPath();
    context.arc(width / 2, height / 2, Math.min(width, height) / 2, 0, 2 * Math.PI);
    context.strokeStyle = 'rgba(0,0,0,0)';
    context.stroke();
    context.clip();
    context.drawImage(sourceCanvas, 0, 0, width, height);

    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,
      built: function () {
        croppable = true;
      }
    });

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

      if (!croppable) {
        return;
      }

      // Crop
      croppedCanvas = cropper.getCroppedCanvas();


      console.log(getImageRatio(croppedCanvas));

    };

  });

})();

任何想法，如何获取裁剪图像的坐标，以便我可以通过 PHP 裁剪该图像。

Answer 1

所以，如果我理解正确的话，您正在寻找 method 获取数据。

它将返回这些属性，如文档所述:

x: the offset left of the cropped area
y: the offset top of the cropped area
width: the width of the cropped area
height: the height of the cropped area
rotate: the rotated degrees of the image
scaleX: the scaling factor to apply on the abscissa of the image
scaleY: the scaling factor to apply on the ordinate of the image

不过，我建议查看文档的这一部分: https://github.com/fengyuanchen/cropper#getcroppedcanvasoptions

具体来说这部分:

After then, you can display the canvas as an image directly, or use HTMLCanvasElement.toDataURL to get a Data URL, or use HTMLCanvasElement.toBlob to get a blob and upload it to server with FormData if the browser supports these APIs.

如果由于某些浏览器限制(您始终可以添加填充)而无法使用 toBlob 方法，则可以在 Canvas 上使用 toDataUrl 获取图像 (IE9+) 。并将其发送到已经裁剪好的后端服务。为此，您需要执行以下操作:

var formData = new FormData();
formData.append('image', canvas.toDataURL());

您可以在caniuse中检查formData浏览器支持

希望您觉得它有帮助!