Bitmap.loadBase64Data卡死，app闪退

var Img = new Image();
Img.src = sd_path;
console.log("1=================================");
Img.onload() = function() {
console.log("2=================================");
var myCanvas = document.createElement("canvas");
myCanvas.width = Img.width;
myCanvas.height = Img.height;
var ctx = myCanvas.getContext("2d");
ctx.drawImage(Img, 0, 0);
ctx.font = "80px microsoft yahei";
ctx.fillStyle = "rgba(255,0,0,1)";

                                                ctx.fillText("拍照时间:" + getNowFormatDate(), 0, Img.height - 100, myCanvas.width - 10);  
                                                console.log("3=================================");  
                                                data = myCanvas.toDataURL();  
                                                //TODO  bitmap 修改图片 start  
                                                var bitmap = new plus.nativeObj.Bitmap();  
                                                console.log("4=================================");  
                                                bitmap.loadBase64Data(data, function() {  
                                                    console.log("加载图片成功");  
                                                }, function() {  
                                                    console.log("加载图片失败");  
                                                });  
                                                bitmap.save(sd_path, {  
                                                    overwrite: true,  
                                                    format: "jpg",  
                                                }, function(i) {  
                                                    var result = JSON.stringify(i);  
                                                    var data = JSON.parse(result);  
                                                    var target = data.target;  
                                                    console.log('保存图片成功：' + result);  
                                                    //start  
                                                    var imageDiv = document.createElement("div");  
                                                    imageDiv.className = "media-item image-item mui-col-"  
                                                    imageDiv.innerHTML = '' +  
                                                        '<img class="file mui-action-preview" data-preview-src="' + target + '" data-preview-group="1" src="' + target + '" addTime="' + (new Date()).getTime() + '" />' +  
                                                        '<span class="mui-icon mui-icon-closeempty"></span>';  
                                                    imageList.appendChild(imageDiv);  
                                                    console.log("加入图片列表的地址:" + target);  
                                                    //在这里获取到图片的路径  
                                                    photoPath = target;  
                                                    bitmap.clear();  
                                                    //end  
                                                }, function(e) {  
                                                    console.log('保存图片失败：' + JSON.stringify(e));  
                                                });  
                                                //TODO  bitmap 修改图片 end  
                                            }*/