如何使用科尔多瓦文件传输下载 base 64 映像

How to download base 64 image using cordova filetransfer

本文关键字：下载 传输 base 映像 文件 何使用      更新时间：2023-09-26

我使用了cordova文件传输协议，并使用下载功能下载base-64图像。当我放置像"https://upload.wikimedia.org/wikipedia/commons/4/4a/Logo_2013_Google.png"这样的远程服务器路径时，它会下载，但是当我将 base-64 图像 pah 放在文件路径上时，它不会下载。我不知道 base-64 转换。请帮忙。

----我的代码如下---- 

  function download(){
        var imageData = image.src;
        imageData = imageData.replace('data:image/png;base64,', '');
        var d = new Date();
        var imageName = "sample" + d.getTime() + ".png";
        //var filepath = encodeURI("https://upload.wikimedia.org/wikipedia/commons/4/4a/Logo_2013_Google.png");
        var filepath = encodeURI(imageData);
        window.requestFileSystem(LocalFileSystem.PERSISTENT, 0, function (fileSystem) {
            fileSystem.root.getFile(imageName, { create: true, exclusive: true }, function (fileEntry) {
                // get the full path to the newly created file on the device
                var localPath = fileEntry.fullPath;
                // massage the path for android devices (not tested)
                if (device.platform === "Android" && localPath.indexOf("file://") === 0) {
                    localPath = localPath.substring(7);
                }
                // download the remote file and save it
                var remoteFile = filepath;
                var fileTransfer = new FileTransfer();
                fileTransfer.download(remoteFile, localPath, function (newFileEntry) {
                    // successful download, continue to the next image
                    console.log('successful download');
                },
                function (error) { // error callback for #download
                    console.log('Error with #download method.', error);
                });
            });
        })
    })
}
}

提前谢谢。

我找到了我自己问题的解决方案。

首先，我将 base64 图像转换为文件流，并使用 Web 服务在服务器上创建图像，并在服务器上上传图像，然后获取该服务器路径并使用 cordova 文件传输下载。

我的代码如下

=> 用于将 base64 图像转换为图像的 Web 服务代码

string strImg = imageData.imageData;
   string fullName = "d:''uploadimages";
   FileStream fs = new FileStream(fullName, FileMode.Create);
   BinaryWriter bw = new BinaryWriter(fs);
   byte[] data = Convert.FromBase64String(strImg);
   bw.Write(data);
   bw.Close();

=> 在手机上下载图片

function download()
{
    var filepath = encodeURI("http://www.telerik.com/sfimages/default-source/logos/app_builder.png"),
    window.requestFileSystem(LocalFileSystem.PERSISTENT, 0, function (fileSystem) {
                fileSystem.root.getFile("sample.jpg", { create: true, exclusive: false }, function (fileEntry) {
                    // get the full path to the newly created file on the device
                    var localPath = fileEntry.fullPath;
                    // massage the path for android devices (not tested)
                    if (device.platform === "Android" && localPath.indexOf("file://") === 0) {
                        localPath = localPath.substring(7);
                    }
                    // download the remote file and save it
                    var remoteFile = filepath;
                    //loadingOverlay.displayLoading("Image will be save on your device.");
                    var fileTransfer = new FileTransfer();
                    fileTransfer.download(remoteFile, localPath, function (newFileEntry) {
                        // successful download, continue to the next image
                        var dwnldImagePath = newFileEntry.fullPath;
                        console.log('successful download');
                    },
                    function (error) { // error callback for #download
                        console.log('Error with #download method.', error);
                    });
                });
                function(error) { // error callback for #getFile
                    console.log('Error with #getFile method.', error);
                });
            })
}
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