需要用MonoDroid和MVVMCross拍攝照片的一個例子

Question

任何人都可以指點我的示例拍攝照片並使用MVVMCross存儲？

我一直在尋找，但只找到了這個：

• Monodroid Take a picture with Camera（沒有實現MVVMCross）

• Video Recording（這是視頻，我不能讓它工作：S ）

• The Oficialy Recipe Example（它的作品，但沒有實現MVVMCross）

謝謝！

已解決！謝謝！
引用未來：（採用主科）
積分斯圖爾特，我只是改變了代碼與我的現實工作

using Cirrious.MvvmCross.ExtensionMethods; 
using Cirrious.MvvmCross.Interfaces.Platform.Tasks; 
using Cirrious.MvvmCross.Interfaces.ServiceProvider; 
using SIGEP.DummyService; 
using SIGEP.Mobile.Core.Interfaces; 


namespace SIGEP.Mobile.Core.Models 
{ 
public class PhotoService : IMvxServiceConsumer<IMvxPictureChooserTask> 
{ 
    private const int MaxPixelDimension = 1024; 
    private const int DefaultJpegQuality = 92; 

    public void GetNewPhoto() 
    { 
     this.GetService<IMvxPictureChooserTask>().TakePicture(
      MaxPixelDimension, 
      DefaultJpegQuality, 
      HandlePhotoAvailable, 
      () => { /* cancel is ignored */ }); 

    } 

    public event EventHandler<PhotoStreamEventArgs> PhotoStreamAvailable; 

    private void HandlePhotoAvailable(Stream pictureStream) 
    { 
     var handler = PhotoStreamAvailable; 
     if (handler != null) 
     { 
      handler(this, new PhotoStreamEventArgs() { PictureStream = pictureStream, OnSucessGettingPhotoFileName = OnSucessGettingPhotoFileName }); 
     } 
    } 



    public static void TakePhoto(Action<string> successFileName, Action<Exception> error) 
    { 
     var service = new PhotoService(); 
     service.OnSucessGettingPhotoFileName = successFileName; 
     service.OnError = error; 
     service.GetNewPhoto(); 
     service.PhotoStreamAvailable += new EventHandler<PhotoStreamEventArgs>(service_PhotoStreamAvailable); 
    } 

    static void service_PhotoStreamAvailable(object sender, PhotoStreamEventArgs e) 
    { 
     //grava pra ficheiro!!! 
     var directory = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments); 
     var filename = Path.Combine(directory, "photo.jpeg"); 
     string saveTo = filename; 
     FileStream writeStream = new FileStream(saveTo, FileMode.Create, FileAccess.Write); 
     ReadWriteStream(e.PictureStream, writeStream); 

     e.OnSucessGettingPhotoFileName(filename); 

    } 
    private static void ReadWriteStream(Stream readStream, Stream writeStream) 
    { 
     int Length = 256; 
     Byte[] buffer = new Byte[Length]; 
     int bytesRead = readStream.Read(buffer, 0, Length); 
     // write the required bytes 
     while (bytesRead > 0) 
     { 
      writeStream.Write(buffer, 0, bytesRead); 
      bytesRead = readStream.Read(buffer, 0, Length); 
     } 
     readStream.Close(); 
     writeStream.Close(); 
    } 

    public Action<string> OnSucessGettingPhotoFileName { get; set; } 
    public Action<Exception> OnError { get; set; } 
} 

[Serializable] 
[ComVisible(true)] 
public class PhotoStreamEventArgs : EventArgs 
{ 
    public Stream PictureStream { get; set; } 

    public Action<string> OnSucessGettingPhotoFileName { get; set; } 
} 
} 

Answer 1

我通常使用實現服務內置IMvxPictureChooserTask（這是一個插件，如果使用vNext）：

using Cirrious.MvvmCross.ExtensionMethods; 
using Cirrious.MvvmCross.Interfaces.Platform.Tasks; 
using Cirrious.MvvmCross.Interfaces.ServiceProvider; 

public class PhotoService 
    : IMvxServiceConsumer<IMvxPictureChooserTask> 
    , IPhotoService 
{ 
    private const int MaxPixelDimension = 1024; 
    private const int DefaultJpegQuality = 92; 

    public void GetNewPhoto() 
    { 
     Trace.Info("Get a new photo started."); 

     this.GetService<IMvxPictureChooserTask>().TakePicture(
      MaxPixelDimension, 
      DefaultJpegQuality, 
      HandlePhotoAvailable, 
      () => { /* cancel is ignored */ }); 
    } 

    public event EventHandler<PhotoStreamEventArgs> PhotoStreamAvailable; 

    private void HandlePhotoAvailable(Stream pictureStream) 
    { 
     Trace.Info("Picture available"); 
     var handler = PhotoStreamAvailable; 
     if (handler != null) 
     { 
      handler(this, new PhotoStreamEventArgs() { PictureStream = pictureStream }); 
     } 
    } 
} 

我一般註冊這個服務在啓動期間一個單，然後從一個ViewModel IComman調用它d處理程序。使用這種服務

---

一個應用程序是Blooor樣本 - 見BaseEditProductViewModel.cs - 這是不是一個樣我有什麼做的，但我相信它帶來了兩個拍照和斑馬線 - 無論是使用外部服務。

---

一個警告：在MonoDroid的，你可以看到一些奇怪的/出乎意料的活動/視圖模型的生命週期行爲 - 基本上你可以看到，活動你從被卸載照片/拍攝照片的過程中，從記憶中抹去了。如果這發生在您的應用程序中，那麼您可能需要開始查看如下問題：Saving Android Activity state using Save Instance State - 這不會在MvvmCross（尚未）中自動處理。

我相信布洛爾樣本可能會遭遇這個問題 - 但用戶是否會看到它在正常的應用程序使用是值得商榷的。

---

至於IMvxPictureChooserTask服務替代方案，你也可以看看使用一些從Xamarin.Mobile跨平臺的API - 見MvvmCross vnext : monodroid use a VideoView inside a plugin一個可能的起點 - 或爲Android只有你可以輕鬆實現你的擁有。