图片类型

URL转base64

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16

function  convertImgToBase64 (url, callback, outputFormat){
    let canvas = document.createElement('CANVAS'),
        ctx = canvas.getContext('2d'),
        img = new Image;
      img.crossOrigin = 'Anonymous';
      img.onload = function(){
          canvas.height = img.height;
          canvas.width = img.width;
          ctx.drawImage(img,0,0);
          let dataURL = canvas.toDataURL(outputFormat || 'image/png');
          callback.call(this, dataURL);
          canvas = null; 
      };
      img.src = url;
    },

案例

1
2
3
4
convertImgToBase64('https:///xxxx.png', function (base64Img) {
        console.log(base64Img)
        
})

base64转file

1
2
3
4
5
6
7
8
9
10
11
12
function dataURLtoFile (dataurl, filename) { 
	    let arr = dataurl.split(','),
	        mime = arr[0].match(/:(.*?);/)[1],
	        bstr = atob(arr[1]),
	        n = bstr.length,
	        u8arr = new Uint8Array(n);
        while (n--) {
            u8arr[n] = bstr.charCodeAt(n);
        }
        console.log(new File([u8arr], filename, { type: mime }))
        return new File([u8arr], filename, { type: mime });
    }