Using toast in conditional action with thread

Question

I have created a login app which login id and password from sql server it works properly for correct login id, password and also gives toast for empty login field

But if I enter incorrect fields. It is not showing desired toast. Perhaps I am using toast in wrong place. My code is

public void onClick(View v) {

            // TODO Auto-generated method stub
            ResultSet rs=null;
            String id=uid.getText().toString();
            String upass=pass.getText().toString();
            final String uid1=null;
            final ProgressDialog pd=new ProgressDialog(MainActivity.this);
            pd.setTitle("Processing");
            pd.setMessage("Processing is going on..plz be patient...");         
            pd.show();
            if(id.equals("")&&upass.equals("")){

                Toast.makeText(getApplicationContext(), "empty id or password", Toast.LENGTH_SHORT).show();
            }


            new Thread(){
                public void run(){
                    //defining task for progress dialog for busy.
                    try{
                        ResultSet rs=null;
                        String id=uid.getText().toString();
                        String upass=pass.getText().toString();
                        String uid1=null;


                        if(!id.isEmpty()&&!upass.isEmpty())
                            try{
                            initilize();
                            Statement statement=connect.createStatement();
                            rs=statement.executeQuery("LOGIN '"+id+"', '"+upass+"'");
                            List<String>data=new ArrayList<String>();
                            if(rs.next()){

                                uid1=rs.getString("PA_NAME");
                                pd.dismiss();
                                Intent i=new Intent(getApplicationContext(),SecondActivity.class);
                                i.putExtra("a", uid1);
                                startActivity(i);
                            }






                            }catch(Exception e){
                                e.printStackTrace();
                            }

                        else
                            Toast.makeText(MainActivity.this, "invalid id or password", Toast.LENGTH_LONG).show();pd.dismiss();





                    }catch(Exception e){                        
                    }
                    pd.dismiss();
                }}.start();

If some one suggest me where to place that toast for incorrect login id. In conditional statement. It's urgent.

Try putting the toast into the catch block probably an exception occurs when credentials are wrong. — Ostkontentitan, Aug 08 '13 at 06:54
Better yet, do nor ignore the excetion. At the very least, you should print a stacktrace. — Code-Apprentice, Oct 02 '16 at 20:19

score 1 · Answer 1 · answered Aug 08 '13 at 06:54

1

You can only create UI objects on the main thread. This includes toasts. Easiest way for you is to use Activity#runOnUiThread to show your toast. You should also check out the Handler class as well.

answered Aug 08 '13 at 06:54

Rich Schuler

41,814
6
72
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Note that by ignoring all exceptions, the OP lost important information which would have told them what the problem is. – Code-Apprentice Oct 02 '16 at 20:21

score 0 · Answer 2 · edited May 23 '17 at 12:33

Using runOnUiThread method:

new Thread() {
    public void run() {
        activity.runOnUiThread(new Runnable() {
            public void run() {
                Toast.makeText(MainActivity.this, "invalid id or password", Toast.LENGTH_LONG).show();
            }
        });
    }
}.start();

Using Handler:

final Handler mHandler = new Handler();
final Runnable mUpdateResults = new Runnable() {
    public void run() {
        Toast.makeText(MainActivity.this, "invalid id or password", Toast.LENGTH_LONG).show();
    }

new Thread() {
    public void run() {
        mHandler.post(mUpdateResults);
    }
}.start();

score 0 · Answer 3 · answered Aug 08 '13 at 06:56

you should show toast in UIthread always. Modify the code as shown below:

runOnUiThread(new Runnable() {

            @Override
            public void run() {
                Toast.makeText(MainActivity.this, "invalid id or password", Toast.LENGTH_LONG).show();
                pd.dismiss();

            }
        });

score 0 · Answer 4 · answered Aug 08 '13 at 06:58

0

Try doing it like that:

MainActivity.runOnUiThread(new Runnable() {
    public void run() {
        Toast.makeText(MainActivity, "Toast on the main Activity", Toast.LENGTH_SHORT).show();
    }
});

answered Aug 08 '13 at 06:58

g00dy

6,752
2
30
43

score 0 · Answer 5 · answered Aug 08 '13 at 07:00

0

best way would be to write a handler in your main activity (UI thread). in the handler show the toast. from thread post a message to that handler.

answered Aug 08 '13 at 07:00

Sushil

8,250
3
39
71

Yes, in else you just post the message to handler and inside handler show the toast. – Sushil Aug 08 '13 at 07:14
put this line in else .. mHandler.post(); – Sushil Aug 08 '13 at 07:15

Using toast in conditional action with thread

5 Answers5