Gallery saver

取得權限的前置作業
iOS
Info.plist內新增
NSPhotoLibraryUsageDescription的權限

Android 
AndroidManifest.xml 內新增
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

程式部分 延續前兩篇

1. image_picker 相簿或拍照選出一張照片

2. image_cropper 裁切或旋轉

3. gallery_saver 存檔至手機相簿(也就是本篇)

在getImage()裡面 呼叫GallerySaver.saveImage(), 並給圖片路徑.

getImage(ImageSource source) async {
    final _picker = ImagePicker();
    XFile? pickedFile = await _picker.pickImage(source: source);
    if (pickedFile != null) {
      imageFilePath = await cropImage(pickedFile.path);
      GallerySaver.saveImage(imageFilePath);
    } 
  }

如果圖片來源自網址

  saveFromUrl(String urlPath) async {
    GallerySaver.saveImage(urlPath).then((bool success) {
        //success callback
    });
  }

來源自網址的影片也可以下載到手機相簿裡
之前處理這段遇到了一個問題是
GallerySaver雖然可以自動判斷是本地路徑或是url
但如果來源的網址很長或被判斷是不可下載的網址
作法改成:

1. 組一個暫存路徑
2. 用Dio下載到一個暫存路徑(這裡用到path_provider)
3. 傳暫存路徑給GallerySaver存到相簿

  Future<bool> saveVideoToAlbum(String urlPath) async {
    //先創一個暫時路徑, getTemporaryDirectory() 需導入path_provider
    Directory appDocDir = await getTemporaryDirectory();
    final String timeStamp = DateTime.now().millisecondsSinceEpoch.toString();
    //檔名暫時用timeStamp命名
    String temporaryPath = appDocDir.path + "$timeStamp.mp4";
    //把檔案用Dio download存到暫時路徑
    final response = await Dio().download(urlPath, temporaryPath,
        onReceiveProgress: (count, total) {
      //這邊是下載進度的換算, 可以從這裡取出數值
      print((count / total * 100).toStringAsFixed(0) + "%");
    });
    //再用GallerySaver存到相簿
    bool? isSucceed = await GallerySaver.saveVideo(temporaryPath);
    if (isSucceed != null) {
      if (isSucceed) {
        //最後再將暫存的檔案刪除
        deleteTemporaryFile(temporaryPath);
        return true;
      }
    }
    return false;
  }
  
  deleteTemporaryFile(String filePath) async {
    try {
      await File(filePath).delete();
    } catch (error) {
      print('Delete TemporaryFile error');
      print(error);
    }
  }

本篇的GitHub source code

下一篇將為大家介紹 flutter_slidable
ListView(iOS的 tableView)左右滑動的操作