QML数据文件夹 [英] QML data folder

问题描述

在我的应用程序基于 QML 我使用相机和 CameraCapture 从相机捕获图像。捕获后，我想使用 CameraCapture.captureToLocation（）将捕获的图像存储在应用程序数据文件夹中。但我不知道如何获得这个文件夹的路径。所以我的问题 - 我怎么能得到应用程序文件夹的路径写的权限？有没有办法在Qt得到它？它应该是系统指定的文件夹，我猜。例如在Android中，它应该是/ data / data / AppName。

Im my app based on QML I use Camera and CameraCapture to capture an image from the camera. After it was captured I want to store captured image in application data folder with CameraCapture.captureToLocation(). But I have no idea how to get path to this folder. So my question - how can I get path to application folder wit write permissions? Is there way in Qt to get it? It should be system specified folder, I guess. For example in Android it should be /data/data/AppName. As I see LocalStorage creates its files in some similar place.

推荐答案

/ data / data / AppName 未映射到 QStandardPaths < a>，但我认为最好使用这个：

/data/data/AppName is not mapped in QStandardPaths, but I think it would be better to use this one:

QStandardPaths :: AppDataLocation 17返回一个目录位置，可以存储。这是一个特定于应用程序的目录。要获取存储要与其他应用程序共享的数据的路径，请使用QStandardPaths :: GenericDataLocation。返回的路径永远不为空。在Windows操作系统上，这将返回漫游路径。此枚举值已在Qt 5.4中添加。

QStandardPaths::AppDataLocation 17 Returns a directory location where persistent application data can be stored. This is an application-specific directory. To obtain a path to store data to be shared with other applications, use QStandardPaths::GenericDataLocation. The returned path is never empty. On the Windows operating system, this returns the roaming path. This enum value was added in Qt 5.4.

或以下版本中的此类：

QStandardPaths :: DataLocation 9返回与AppLocalDataLocation相同的值。此枚举值已弃用。使用AppDataLocation是首选，因为在Windows上，建议使用漫游路径。

QStandardPaths::DataLocation 9 Returns the same value as AppLocalDataLocation. This enumeration value is deprecated. Using AppDataLocation is preferable since on Windows, the roaming path is recommended.

这些将设置为 DataLocation < APPROOT> / files，< USER> /< APPNAME> / files。

从5.4开始，后者被废除为文件。您可以将其设置为以下：

But note that from 5.4 on, the latter is deprecated as documented. You can set it then as follows:

QString QStandardPaths :: writableLocation（StandardLocation type）

QString QStandardPaths::​writableLocation(StandardLocation type)

返回文件

注意：返回的存储位置可以是不存在的目录，也可以是不存在的目录。

Note: The storage location returned can be a directory that does not exist; i.e., it may need to be created by the system or the user.

所以，你会这样写：

QString dataPath = QStandardPaths::​writableLocation(QStandardPaths::AppDataLocation);
// Do not need to check against empty string for this value as per documentatio
CameraCapture.captureToLocation(dataPath);

注意：请不要使用 QStandardPaths :: ApplicationsLocation 为此目的，因为那是非专用位置。此外，Android甚至不支持它：

Note: Please do not use QStandardPaths::ApplicationsLocation for this purpose since that is the non-dedicated location. In addition, it is even unsupported on Android:

ApplicationsLocation不支持（目录不可读）

ApplicationsLocation not supported (directory not readable)

如果要跨应用程序共享图像，则需要使用此方法，并对上述代码进行细微调整。虽然我想你想要上面的一个，它是有点不清楚你想要哪一个，所以我提到两个：

If you want to share the image across applications, you would need to use this with minor adjustment to the code above. While I think you wanted the one above, it is a bit unclear which one you wanted, so I am mentioning both:

StandardPaths :: GenericDataLocation 11返回可以存储应用程序共享的持久数据的目录位置。这是一个通用值。返回的路径永远不为空。

StandardPaths::GenericDataLocation 11 Returns a directory location where persistent data shared across applications can be stored. This is a generic value. The returned path is never empty.

这是设置为 GenericDataLocation< USER>。确切的映射在类文档中提到，你只需要向下滚动到表。我不能给直接的URL，因为没有固定链接到那个部分。你也可以检查自己，这是最好的。

This is set to GenericDataLocation "<USER>" on Android. The exact mappings are mentioned in the class documentation, you just need to scroll down to the tables. I cannot give direct URL as there is no permalink to that section. You can check yourself, too, which fits the best.

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