Question

我需要将多个图像保存到文件系统。但是在文件系统中只输入了最后一张图像。我怎么解决这个问题？

这是我的代码：

            // Loop through each image and to create image blob
            for(var slide in slides)
            {
                    var image = "http://localhost:5441"+slides[slide].background.src;
                    xhrDownloadImage(image, function (imageAsBlob) {
                    });
                }
            }

            // Function to create blob
            var ids = [];
            var xhrDownloadImage = function (url, callback) {
            var xhr = new XMLHttpRequest();

            xhr.open("GET", url, true);
            xhr.responseType = "blob";

            xhr.onerror = function(e){console.log("Error: " + e)};
            xhr.onabort = function(e){console.log("Abort: " + e)};

            xhr.onload = function () {

                console.log("onload");

                var result;

                if (xhr.status === 200) {
                    // image as blob
                    result = xhr.response;
                    ids.push(result);
                    console.log(result);
                } else {
                    result = null;
                }

                callback(result);
            };

            console.log(xhr.send());
        };

          // Now ids array has all image blobs 

         //Following function is to write image blobs in ids to file systems
         function writedata(){
            console.log(ids);

            for(var i in ids)
            {
                alert("image"+i+".png");
                setTimeout(function () {
                     (function () {
                fs.root.getFile("image"+i+".png", { create: true }, function (fileEntry) {
                alert("fileimage"+n+".png");
                    console.log(fileEntry);
                    fileEntry.createWriter(function (fileWriter) {

                        fileWriter.onwriteend = function (e) {
                            console.log("image successfully written to filesystem.");

                        };

                        var blob = new Blob([ids[i]]);
                        fileWriter.write(blob);
                    }, errorHandler);
                }, errorHandler);
                          })(i)
            }, i * 1000);

            }
        }

Answer 1

我开始工作了......

将writedata fn更改为

  function writedata() {
        console.log(filesystem);
        console.log(ids);
        for (var i = 0; i < ids.images.length; i++) {

            var n = -1;

            setTimeout(function() {
                (function() {
                    filesystem.root.getFile(ids.images[n + 1].name, {
                        create: true
                    }, function(fileEntry) {

                        console.log(fileEntry);
                        fileEntry.createWriter(function(fileWriter) {

                            fileWriter.onwriteend = function(e) {
                                console.log("image successfully written to filesystem.");

                            };

                            var blob = new Blob([ids.images[n].blob]); // instead i (ie looping variable), n is used which increments only after writing each file to file system
                            fileWriter.write(blob);
                        }, errorHandler);
                    }, errorHandler);
                    n = n + 1;
                })(i)
            }, i * 1000);
        }
    }

将多个图像上传到文件系统

1 个答案: