Alert Dialog Validation in android
<p>When i click the save button without entering values the dialog gets disappear.I want to show the dialog box as well as want to do the validation.Please help me if anybody knows.</p>

<p>Here is my code:   </p>

<pre><code> TextView tvUserName=new TextView(this);
            TextView tvPassword=new TextView(this);
            TextView tvURL=new TextView(this);
            final EditText etUserName=new EditText(this); 
            final EditText etPassword=new EditText(this);
            final AlertDialog.Builder alert = new AlertDialog.Builder(this);    
            LinearLayout login= new LinearLayout(this);
            login.setOrientation(1); //1 is for vertical orientation
            tvUserName.setText(getResources().getString(R.string.username));
            tvPassword.setText(getResources().getString(R.string.password));
            login.addView(tvURL);
            login.addView(etURL);
            login.addView(tvUserName);
            login.addView(etUserName);
            login.addView(tvPassword);
            etPassword.setInputType(InputType.TYPE_CLASS_TEXT |InputType.TYPE_TEXT_VARIATION_PASSWORD);
            login.addView(etPassword);
            alert.setView(login);
            alert.setTitle(getResources().getString(R.string.login));
            alert.setPositiveButton(getResources().getString(R.string.login), new DialogInterface.OnClickListener() {             
                public void onClick(final DialogInterface dialog, int whichButton) {   
                    strUserName=etUserName.getText().toString();
                    XmlUtil.username=strUserName;
                    strPassword=etPassword.getText().toString();
                    strhwdXml=etURL.getText().toString();
                    if((strUserName.length()==0)||(strPassword.length()==0){
    Toast.makeText(getBaseContext(),"Please enter username and password", Toast.LENGTH_SHORT).show();

                    }else {
                        Toast.makeText(getBaseContext(),"Success", Toast.LENGTH_SHORT).show();
                    }
</code></pre>
