Vue.js 2.0 移动端拍照压缩图片预览及上传实例

注意：后端接收到我传递的base64字符串数组的时候，发现字符经如果被urlencode后标准的base64中的/、 +会被转成%xx，后端在将base64字符串处理成图片时，需要将特殊字符过滤掉。

[HttpPost]    public ActionResult MUploadImgBase64Str(string base64str)
    {
      try
      {
        var imgData = base64str;
        //过滤特殊字符即可
        string dummyData = imgData.Trim().Replace("%", "").Replace(",", "").Replace(" ", "+");
        if (dummyData.Length % 4 > 0)
        {
          dummyData = dummyData.PadRight(dummyData.Length + 4 - dummyData.Length % 4, '=');
        }
        byte[] byteArray = Convert.FromBase64String(dummyData);
        using (System.IO.MemoryStream ms = new System.IO.MemoryStream(byteArray))
        {
          var img = System.Drawing.Image.FromStream(ms);
          var path = "~/Content/UploadFiles/mobile/";
          var uploadpath = Server.MapPath(path);
          if (!Directory.Exists(uploadpath))
          {
            Directory.CreateDirectory(uploadpath);
          }
          var saveName = uploadpath + “stoneniqiu” + ".jpg";
          img.Save(saveName);
          return Json(saveName);
        }
      }
      catch (Exception e)
      {
        return Json(e.Message);
      }
    }