檢查用戶對Intent.ACTION_VIEW的行爲

Question

我有一個列表視圖填充了一些文件，可以有各種類型，如pdf或documents.When用戶點擊一個我得到的文件MIME類型，並啓動一個意圖，讓用戶選擇使用哪個應用程序來打開該文件。我想要知道的是用戶選擇了某種內容，或者只是簡單地按下並且沒有選擇任何內容。 是我的嘗試，直到現在在做一個startActivityForResult和檢查的成功，但它總是返回RESULT_CANCELED

static final int SELECTED_VIEWER = 1; 

    Intent intent = new Intent(Intent.ACTION_VIEW);  
    intent.setDataAndType(Uri.parse(filePath), mimetype); 
    try { 
     startActivityForResult(intent, SELECTED_VIEWER); 
    }catch (ActivityNotFoundException e) { 
     Toast.makeText(getActivity(), 
      Strings.ERROR_NO_VIEWER, 
      Toast.LENGTH_SHORT).show(); 
    } 

    public void onActivityResult(int requestCode, int resultCode, Intent data) { 
    if (requestCode == SELECTED_VIEWER) { 
     if (resultCode == Activity.RESULT_CANCELED) { 
      //do something 
     } 
    } 
} 

我甚至用startActivityForResult（Intent.createChooser但仍無濟於事嘗試。 我怎麼能知道，如果用戶選用一些名單上，或者如果他取消了開放？

Answer 1

寫在Android開發者對Activities

在其他協議（例如ACTION_MAIN或ACTION_VIEW）中，如果您期望，可能無法獲得結果。

不能行動的意見返回你所期望的算，所以我所做的就是實現一個自定義警告對話框，顯示可以打開某個文件，略加修改所有可能的應用如下圖所示Custom intent chooser

對於那些想知道，它需要一個文件路徑作爲參數，並顯示你所有已安裝的應用程序可以通過獲取與fullpaths.Can的mimetype.Works處理該文件類型代碼

AlertDialogIntentChooser alertDialog = new AlertDialogIntentChooser(filePath,getActivity()); 
alertDialog.show(); 

被稱爲這是類，它可以採取選擇有理代表藏漢爲活動回調

public class AlertDialogIntentChooser { 
private String filePath; 
private Activity activity; 
private AlertDialog dialog; 
private AlertDialogDelegate delegate; 
private ListItem[] items; 

public AlertDialogIntentChooser(String filePath,Activity activity){ 
    this.filePath = filePath; 
    this.activity = activity; 
    init(); 
} 

public void setDialogDelegate(AlertDialogDelegate delegate){ 
    this.delegate = delegate; 
} 

private void init(){ 

    initApplicationItems(); 

    AlertDialog.Builder builder = new AlertDialog.Builder(activity); 
    builder.setTitle(Strings.STRING_SELECT_APPLICATION); 
    builder.setIcon(R.drawable.ic_share); 

    builder.setOnCancelListener(new OnCancelListener() { 

     @Override 
     public void onCancel(DialogInterface paramDialogInterface) { 
      if(delegate!=null) 
       delegate.onDialogCancelled(paramDialogInterface); 
     } 
    }); 

    builder.setAdapter(adapter, new DialogInterface.OnClickListener() { 
     @Override 
     public void onClick(DialogInterface dialog, int which) {   

      Intent intentPdf = new Intent(Intent.ACTION_VIEW); 
      MimeTypeMap myMime = MimeTypeMap.getSingleton(); 
      String fileExt = MimeTypeMap.getFileExtensionFromUrl(Uri.parse(filePath)); 
      String mimeType = myMime.getMimeTypeFromExtension(fileExt);     
      intentPdf.setClassName(items[which].context, items[which].packageClassName); 
      intentPdf.setDataAndType(Uri.parse(filePath), mimeType); 
      try { 
       activity.startActivity(intentPdf); 
       dialog.dismiss(); 
       if(delegate!=null) 
        delegate.onItemSelected(items[which].context, items[which].packageClassName); 
      }catch (ActivityNotFoundException e) { 
       Toast.makeText(activity, 
         Strings.ERROR_NO_VIEWER, 
         Toast.LENGTH_SHORT).show(); 
       dialog.dismiss(); 
      }    
     } 
    }); 

    dialog = builder.create();   
} 

private void initApplicationItems(){ 
    Intent intentPdf = new Intent(Intent.ACTION_VIEW); 

    MimeTypeMap myMime = MimeTypeMap.getSingleton(); 
    String fileExt = MimeTypeMap.getFileExtensionFromUrl(Uri.parse(filePath)); 
    String mimeType = myMime.getMimeTypeFromExtension(fileExt);    
    intentPdf.setDataAndType(Uri.parse(filePath), mimeType); 
    PackageManager pm = activity.getPackageManager(); 
    List<ResolveInfo> resInfos = pm.queryIntentActivities(intentPdf, 0); 

    items = new ListItem[resInfos.size()]; 
    int i = 0; 
    for (ResolveInfo resInfo : resInfos) { 
     String context = resInfo.activityInfo.packageName; 
     String packageClassName = resInfo.activityInfo.name; 
     CharSequence label = resInfo.loadLabel(pm); 
     Drawable icon = resInfo.loadIcon(pm); 
     items[i] = new ListItem(label.toString(), icon, context, packageClassName); 
     ++i; 
    } 
} 

public void show(){ 
    dialog.show(); 
} 

private ListAdapter adapter = new ArrayAdapter<ListItem>(
      activity, 
    android.R.layout.select_dialog_item, 
    android.R.id.text1, 
    items){ 

    public View getView(int position, View convertView, ViewGroup parent) { 

     View v = super.getView(position, convertView, parent); 
     TextView tv = (TextView)v.findViewById(android.R.id.text1); 

     int dpS = (int) (72 * activity.getResources().getDisplayMetrics().density * 0.5f); 
     items[position].icon.setBounds(0, 0, dpS, dpS); 
     tv.setCompoundDrawables(items[position].icon, null, null, null); 

     int dp5 = (int) (5 * activity.getResources().getDisplayMetrics().density * 0.5f); 
     tv.setCompoundDrawablePadding(dp5); 

     return v; 
    } 
}; 

class ListItem { 
    public final String name; 
    public final Drawable icon; 
    public final String context; 
    public final String packageClassName; 

    public ListItem(String text, Drawable icon, String context, String packageClassName) { 
     this.name = text; 
     this.icon = icon; 
     this.context = context; 
     this.packageClassName = packageClassName; 
    } 

    @Override 
    public String toString() { 
     return name; 
    } 
} 

public static interface AlertDialogDelegate{ 
    public void onDialogCancelled(DialogInterface paramDialogInterface); 
    public void onItemSelected(String packageName, String className); 
} 
} 

Answer 2

試試這個..

Intent intent = new Intent(Intent.ACTION_VIEW);  
     intent.setDataAndType(Uri.parse(filePath),mimetype); 
     startActivity(intent); 

Answer 3

嘗試

如果（resultCode爲== RESULT_CANCELED）而不是 如果（resultCode爲== Activity.RESULT_CANCELED）