Try replacing your getView()
s with getDialog()
.
EditText eF = (EditText)getDialog().findViewById(R.id.editFach);
fach = eF.getText().toString();
EditText eR = (EditText)getDialog().findViewById(R.id.editRaum);
raum = eR.getText().toString();
EditText eL = (EditText)getDialog().findViewById(R.id.editLehrer);
lehrer = eL.getText().toString();