Question

我正在使用C＃为Windows Phone 8.1 RT制作相机应用程序，并希望将GPS位置添加到刚刚拍摄的图片的元数据中。

从GPS读取位置数据不是问题。从（在这种情况下）image.jpg中读取元数据不是问题。然而，编写/编辑数据是因为某些字段是只读的。

拍照，然后保存：

public async void take_picture()
{
    ImageEncodingProperties format = ImageEncodingProperties.CreateJpeg();
    format.Width = resolutionwidth;
    format.Height = resolutionheight;

    var imageStream = new InMemoryRandomAccessStream();
    await captureManager.CapturePhotoToStreamAsync(format, imageStream);
    //some more code

    StorageFile file = await KnownFolders.PicturesLibrary.CreateFileAsync("nameofpicture.jpg", CreationCollisionOption.GenerateUniqueName);
    var fileStream = await file.OpenAsync(FileAccessMode.ReadWrite);
    await RandomAccessStream.CopyAsync(imageStream, fileStream);
}

阅读元数据。（这些属性现在为空，但可以从另一张图片中读取属性。）

private async void metaread_button_click(object sender, RoutedEventArgs e)
{
    StorageFile file1 = await KnownFolders.PicturesLibrary.GetFileAsync("nameofpicture.jpg");
    var fileprops = await file1.Properties.GetImagePropertiesAsync();
    textblock1.Text = "manufacturer: " + fileprops.CameraManufacturer; //writable property
    textblock2.Text = "model: " + fileprops.CameraModel; //writable property
    textblock3.Text = "title: " + fileprops.Title; //writable property
    textblock4.Text = "latitude: " + fileprops.Latitude; //readonly property
    textblock5.Text = "longtitude: " + fileprops.Longitude; //readonly property
    textblock6.Text = "orientation: " + fileprops.Orientation; //readonly property
}

修改可写元数据：

private async void metawrite_button_click(object sender, RoutedEventArgs e)
{
    StorageFile file2 = await KnownFolders.PicturesLibrary.GetFileAsync("nameofpicture.jpg");
    var fileprops = await file2.Properties.GetImagePropertiesAsync();
    fileprops.Title = "picture by me";
    await fileprops.SavePropertiesAsync();
}

问题：如何设置只读属性？＆＃34; ImageEncodingProperties＆＃34;设置图像的属性，但不设置文件。

Answer 1

终于找到了答案。请参阅RD8388的回答。只需要将lat / long转换为Degree / Minute / Second格式。你不需要按照他的建议去评论经度分母。只需确保你的秒数（分子属性）除以分母落在预期的范围内。

http://answers.flyppdevportal.com/categories/metro/csharpvb.aspx?ID=aaf0b373-b0e0-4d91-84d8-69e768a374d8

如何在Windows Phone 8.1 RT上添加GPS数据到元数据

1 个答案: