cordova图片下载

我们将介绍两种方式将照片保存到本地

• 官方下载插件FileTransfer

  这种方式会有一个弊端就是图片在相册里面找不到需要刷新一下系统目录或者重启一下手机才能在相册里面查看到图片但是可以下载动图

    vm.url = encodeURI(baseConfig.imgPath + vm.nowImgs[vm.nowImgIndex]);
    vm.fileName = vm.nowImgs[vm.nowImgIndex].split("/").pop();
    var fileTransfer = new FileTransfer();
    var trustHosts = true;
    var options = {
        headers: {
          "Authorization": 'access_token'
        }
     };
    //Android：
    vm.fileURL = cordova.file.externalRootDirectory;
    window.resolveLocalFileSystemURL(vm.fileURL, function (fileEntry) {
      fileEntry.getDirectory("Giti", {create: true, exclusive: false}, function (fileEntry) {
        fileEntry.getDirectory("img", {create: true, exclusive: false}, function (fileEntry) {
          fileTransfer.download(
            vm.url,
            fileEntry.toURL() + vm.fileName,
            function (success) {
              
            },
            function (error) {
            
            },
            options,
            trustHosts
          );
        }, function () {
          publicMethod.showLoadingNoBackdrop('img文件夹创建失败');
        });
      }, function () {
        publicMethod.showLoadingNoBackdrop('Giti文件夹创建失败');
      });
    });
    // iOS
    vm.fileURL = cordova.file.documentsDirectory + vm.fileName;
    window.requestFileSystem(LocalFileSystem.PERSISTENT, 5 * 1024 * 1024, function (fs) {
      fs.root.getDirectory('Giti', {create: true, exclusive: false}, function (directory) {
        fileTransfer.download(
          vm.url,
          directory.nativeURL + vm.fileName,
          function (success) {
           
          },
          function (error) {
            
          },
          trustHosts,
          options
        );
      });
    });
  

• Canvas2ImagePlugin插件

  这种方法可以直接在相册里面看到图片但是动图看不到，下面是参考代码

    function keepImg(){
        var success = function (msg) {
        
        };
        var error = function (err) {
        
        };
        saveImageToPhone(vm.url, success, error);
    }
            
    function saveImageToPhone(url, success, error) {
      var canvas, context, imageDataUrl, imageData;
      var img = new Image();
      img.src = url;
      img.onload = function () {
        console.log('Img size: ' + img.naturalWidth + 'x' + img.naturalHeight);
        canvas = document.createElement('canvas');
        canvas.width = img.width;
        canvas.height = img.height;
        context = canvas.getContext('2d');
        context.drawImage(img, 0, 0);
        try {
          imageDataUrl = canvas.toDataURL('image/jpeg', 1.0);
          imageData = imageDataUrl.replace(/data:image\/jpeg;base64,/, '');
          cordova.exec(
            success,
            error,
            'Canvas2ImagePlugin',
            'saveImageDataToLibrary',
            [imageData]
          );
        }
        catch (e) {
          error(e.message);
        }
      };
      try {
        img.src = url;
        console.log("153" + img.src);
      }
      catch (e) {
        console.log("156" + img.src);
        error(e.message);
      }
    }