Camera.MAUI拍摄图片后无法正确保存为PNG文件求助

你当前的错误在于将NewImage.Source的字符串表示（即类型名称）写入文件，而不是快照的实际二进制数据。GetSnapShot返回的IImageSource本质是StreamImageSource，需要从中提取图片流并转换为字节数组才能正确保存。

修改步骤及代码 #

1. 在页面类中添加私有字段存储捕获的图片字节：

private byte[] _capturedPhotoBytes;

2. 修改拍照按钮点击事件，捕获图片实际字节：

private async void TakePhotoButton_Clicked(object sender, EventArgs e)
{
    var imageSource = cameraView.GetSnapShot(Camera.MAUI.ImageFormat.PNG) as StreamImageSource;
    if (imageSource == null)
    {
        await DisplayAlert("Error", "Failed to capture photo", "OK");
        return;
    }

    // 从StreamImageSource提取字节数组
    using (var stream = await imageSource.Stream(CancellationToken.None))
    using (var memoryStream = new MemoryStream())
    {
        await stream.CopyToAsync(memoryStream);
        _capturedPhotoBytes = memoryStream.ToArray();
    }

    NewImage.Source = imageSource;
    SavePhoto.IsEnabled = true;
    FileNameEntry.IsEnabled = true;
}

3. 修改保存按钮点击事件，使用预存字节数组写入文件：

private async void SavePhotoButton_Clicked(object sender, EventArgs e)
{
    if (string.IsNullOrEmpty(FileNameEntry.Text))
    {
         await DisplayAlert("Missing Info", "Enter File Name", "OK");
        return;
    }

    if (_capturedPhotoBytes == null || _capturedPhotoBytes.Length == 0)
    {
        await DisplayAlert("Error", "No photo captured to save", "OK");
        return;
    }

    string photoFileName = $"{FileNameEntry.Text.ToLower()}.png";
    string myPicPath = Environment.GetFolderPath(Environment.SpecialFolder.MyPictures);
    var folderPath = Path.Combine(myPicPath, "CapsnPins");

    if (!Directory.Exists(folderPath))
    {
        Directory.CreateDirectory(folderPath);
    }

    string filePath = Path.Combine(folderPath, photoFileName);

    await File.WriteAllBytesAsync(filePath, _capturedPhotoBytes, CancellationToken.None);
    await DisplayAlert("Saved Photo", $"Successfully saved {photoFileName}", "OK");
}

关键修改说明 #

• 新增_capturedPhotoBytes字段直接存储图片二进制数据，避免从UI控件Source中错误提取内容
• 拍照时将StreamImageSource转换为字节数组，确保获取到真实图片数据
• 保存阶段直接使用预存的字节数组写入文件，不再处理Source的字符串表示
• 增加空值检查，避免无图片时执行无效保存操作
• 简化文件名拼接逻辑，修正了"Succssfully"的拼写错误

内容的提问来源于stack exchange，提问作者Michael Amarello