Android : showing softkeyboard in android on landscape orientation

EditText textView = (EditText ) findViewById(R.id.editText1);
textView.requestFocus();
InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
imm.showSoftInput(textView, InputMethodManager.SHOW_IMPLICIT);

I use this code to open soft keyboard automatically . it works fine in normal situation but when I change it to landscape orientation android:screenOrientation="landscape" in manifest, it stops working. what's wrong with it?