加载base64图片出现黑线

图片加载后会出现黑线

右击下载图片则显示正常

，调试情况下也显示正常，刷新后则不再出现。

贴上代码

  var drawtable = [];
    var handlerUrl = "/xxx/xxxHander.ashx?v=" + Math.random();

    //获得画
    $.ajax({
        async: false,
        type: "POST", //GET
        url: encodeURI(handlerUrl),
        data: "action=drawimage,
        beforeSend: function (XMLHttpRequest) {
            $("<div class='loadingWrap'></div>").appendTo("body");
        },
        success: function (data, textStatus) {
            if (data != "") {

                var jsonObj = JSON.parse(data);
                var imagegriddiv = document.getElementById("imagegrid");//
                for (var i = 0; i < jsonObj.length; i++) {
                    movenullstr(jsonObj[i]);
                    var imageindex = parseInt($("#<%=hideImageIndex.ClientID %>").val()) + 1;//获得当前页面的id
                    var div = document.createElement("div");
                    var img = document.createElement("img");
                    var txt = document.createElement("p");
                    var checkdiv = document.createElement("div");
                    var checkinput = document.createElement("input");
                    div.className = "grid__item";
                    img.className = "grid__item_img";
                    txt.innerText = jsonObj[i].ImageNumInfo;

                    img.src = jsonObj[i].Image;
                    img.id = jsonObj[i].ID;
                    div.appendChild(img);
                    div.appendChild(txt);
                    checkdiv.className = "checkdiv";
                    checkinput.type = "checkbox";
                    checkinput.name = jsonObj[i].ID;
                    checkinput.id = "box" + imageindex;
                    checkinput.checked = false;
                    checkdiv.appendChild(checkinput);
                    div.appendChild(checkdiv);
                    imagegriddiv.appendChild(div);
                }



            }

        },
        complete: function (XMLHttpRequest, textStatus) {
            $(".loadingWrap").remove();
        },
        error: function (XMLHttpRequest, textStatus, errorThrown) {
            alert("执行失败！原因：" + XMLHttpRequest.status + ";" + XMLHttpRequest.readyState + ";" + textStatus);
            r = "error";
        }
    });
}

  <div class="grid" id="imagegrid" style="height: 580px;">
                    <div class="uploadImgBtn" id="uploadImgBtnSetup">
                        <img src="xxx/xxx.jpg" alt="xxx/xxx.jpg" class="grid__item" />
                        <input class="uploadImg" type="file" name="file" multiple id="file" data-size="1280x853" />
                    </div> 
    </div>

https://blog.csdn.net/dd2016124/article/details/85119946