應用程序在採摘圖像時崩潰

Question

我正在使用下面的代碼上傳圖像。

public async void btnAttachment_Tapped(object sender, EventArgs e) 
{ 
    await CrossMedia.Current.Initialize(); 
    if (!CrossMedia.Current.IsPickPhotoSupported) 
    { 
     await DisplayAlert("Photos Not Supported", ":(Permission not granted to photos.", "OK"); 
     return; 
    } 

    _mediaFile = await CrossMedia.Current.PickPhotoAsync(); 

    if (_mediaFile == null) 
     return; 

    LocalPathLable.Text = _mediaFile.Path; 

    FileImage.Source = ImageSource.FromStream(() => 
    { 
     var stream = _mediaFile.GetStream(); 
     _mediaFile.Dispose(); 
     return stream; 

    }); 
} 

在該選擇圖像後，應用程序突然崩潰。

Answer 1

我從來沒有發現跨媒體插件上傳現有的照片代碼工作。相反，我使用依賴注入來實現本地圖庫選擇。一旦你有了url，你可以將它貼在圖像視圖中，或者將它作爲位圖或其他任何東西在本地代碼中膨脹。實際上，我將Model.Photo傳回照片的名稱和字節[]，但這取決於您。

PCL

var x = await DependencyService.Get<IMedia>().UploadGallery(); 

的Android

class Media_Android : Activity, IMedia 
{ 
    public async Task<string> UploadGallery() 
    { 
      var activity = Forms.Context as MainActivity; 

      Intent intent = new Intent(); 
      intent.SetType("image/*"); 
      intent.SetAction(Intent.ActionGetContent); 


      var result = await activity.StartActivityForResultAsync(intent); 

      if(result.Data != null) 
      { 
       Android.Net.Uri myUri = result.Data.Data; 

       var getString = this.GetPathToImage(myUri); 

       if (getString != null) 
       { 
        return getString; 
       } 
       else 
       { 
        return null; 
       } 
      } 
      else 
      { 
       return null; 
      } 
    } 
} 

private string GetPathToImage(Android.Net.Uri uri) 
{ 


     int currentapiVersion = (int)Android.OS.Build.VERSION.SdkInt; // Gets the Android version number for ex:- Lollipop 21-22, KitKat 19–20, JellyBean: 16-18. 
     string path = ""; 
     // "KitKat 4.4(KitKat) and above compatible" 
     if (currentapiVersion > (int)Android.OS.BuildVersionCodes.JellyBeanMr2) 
     { 
      Android.Database.ICursor cursor1 = Forms.Context.ContentResolver.Query(uri, null, null, null, null); 
      cursor1.MoveToFirst(); 
      string document_id = cursor1.GetString(0); 
      if(document_id.Contains(":")) 
      { 
       document_id = document_id.Split(':')[1]; 
      } 
      cursor1.Close(); //Extract the ID from the URI 

      cursor1 = Forms.Context.ContentResolver.Query(
      Android.Provider.MediaStore.Images.Media.ExternalContentUri, 
      null, MediaStore.Images.Media.InterfaceConsts.Id + " = ? ", new System.String[] { document_id }, null); 
      cursor1.MoveToFirst(); 
      path = cursor1.GetString(cursor1.GetColumnIndex(MediaStore.Images.Media.InterfaceConsts.Data)); 
      cursor1.Close(); //Query the device database, to get the Image based on the ID 


     } 



     //"JellyBean 4.1 - 4.3.1 (JellyBean) and below compatible" 
     if (currentapiVersion <= (int)Android.OS.BuildVersionCodes.JellyBeanMr2) 
     { 
      System.String[] projection = new System.String[] { Android.Provider.MediaStore.MediaColumns.Data }; 
      contentResolver = Forms.Context.ContentResolver; 
      Android.Database.ICursor cursor = contentResolver.Query(uri, projection, null, null, null); 
      if (cursor != null && cursor.Count > 0) 
      { 
       cursor.MoveToFirst(); 
       int index = cursor.GetColumnIndex(Android.Provider.MediaStore.MediaColumns.Data); 
       path = cursor.GetString(index); 


      } 
     } 

     return path; 

} 

的iOS

這是很容易比Android只是谷歌。