android Call ListActivity from activity class - android-listview

Question

I have layouts main activity and another list activity. But when i try to call list activity i am getting crash. Please help me to start list activity (Note: List activity has EditText and button to add text to existing listview in list Activity)
All i wanted to add text listview which is already exist in listactivity.
Many Thanks!!
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void onClick(View view){
EditText txt=(EditText)findViewById(R.id.txtPass);
if (txt.getText().length()==0){
Toast.makeText(this, "Please enter password to continue!!", Toast.LENGTH_SHORT).show();
txt.getText().clear();
return;
}
if(txt.getText().toString().contains("Test")){
Button btn;
btn=(Button)findViewById(R.id.btnSubmit);
Intent intent=new Intent(this,Passwordlist.class);
startActivity(intent);
}
}

Answer 1

First, make some change to your code:
Button btn;
EditText txt
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//Do this stuff here and not in onClick. Your views should be defined in //onCreate() and before the onCLick()
txt=(EditText)findViewById(R.id.txtPass);
btn=(Button)findViewById(R.id.btnSubmit);
}
public void onClick(View view){
Intent intent=new Intent(YourActivity.this,Passwordlist.class);
if (txt.getText().toString().matches("")){
Toast.makeText(this, "Please enter password to continue!!", Toast.LENGTH_SHORT).show();
txt.getText().clear();
}
else if(txt.getText().toString().contains("Test")){
startActivity(intent);
}
}
See if this works.