Reputation: 113
How to show Alert Dialog in static method, i am trying to put a condition, in which i am checking for the folder inside the SD Card, if exist then listing Items, otherwise i want to show AlertDialog - with message no folder found with Church Name
public static List <String> fromSDCard()
{
List <String> listChurchWall = new ArrayList <String>();
// listing Wallpaper using church names
String string = "/mnt/sdcard/Church/Wallpaper/";
f = new File (string+name+"/");
if (f.exists())
{
files = f.listFiles ();
}else{
// here i want to put AlertDialog
}
return listChurchWall;
}
Upvotes: 2
Views: 2557
Reputation: 2786
Pass your app context to the static method.
public static List <String> fromSDCard(Context context)
{
List <String> listChurchWall = new ArrayList <String>();
// listing Wallpaper using church names
String string = "/mnt/sdcard/Church/Wallpaper/";
f = new File (string+name+"/");
if (f.exists())
{
files = f.listFiles ();
}else{
// 1. Instantiate an AlertDialog.Builder with its constructor
AlertDialog.Builder builder = new AlertDialog.Builder(context);
// 2. Chain together various setter methods to set the dialog characteristics
builder.setMessage(R.string.dialog_message)
.setTitle(R.string.dialog_title);
// 3. Get the AlertDialog from create()
AlertDialog dialog = builder.create();
// 4. Show the dialog
dialog.show()
}
return listChurchWall;
}
If calling from your activity.
public MyActivity extends Activity
{
....
private void Method()
{
List<String> list = fromSdCard(this);
}
....
}
Upvotes: 3
Reputation: 23344
Try the following way--
public static List <String> fromSDCard(Activity a, String title, String message)
{
List <String> listChurchWall = new ArrayList <String>();
// listing Wallpaper using church names
String string = "/mnt/sdcard/Church/Wallpaper/";
f = new File (string+name+"/");
if (f.exists())
{
files = f.listFiles ();
}
else
{
AlertDialog.Builder dialog = new AlertDialog.Builder(a);
dialog.setTitle(title);
dialog.setMessage(message);
dialog.setNeutralButton("OK", null);
dialog.create().show();
}
return listChurchWall;
}
Then in your class do---
public MyActivity extends Activity
{
....
private Method()
{
List<String> list = fromSdCard(this, "Your Title", "Your message");
}
....
}
UPDATE:
You get a NullPointerException
because something is null that shouldn't be. It happens while sorting the array, so perhaps one of the array elements is null. Take a look at how you assign values to your array.
Perhaps at the top of it, see if any of the objects Object o1
or Object o2
themselves are null.
Upvotes: 1
Reputation: 28484
public static List<String> fromSDCard(Context mContext) {
List<String> listChurchWall = new ArrayList<String>();
// listing Wallpaper using church names
String string = "/mnt/sdcard/Church/Wallpaper/";
f = new File(string + name + "/");
if (f.exists()) {
files = f.listFiles();
} else {
AlertDialog.Builder builder = new AlertDialog.Builder(mContext);
int imageResource = android.R.drawable.stat_sys_warning;
Drawable image = mContext.getResources().getDrawable(imageResource);
builder.setTitle("title").setMessage("your Message").setIcon(image).setCancelable(false).setNeutralButton("Ok", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
}
});
AlertDialog alert = builder.create();
alert.setCancelable(false);
alert.show();
}
return listChurchWall;
}
Upvotes: 1