一个活动中的微调器并刷新活动

Question

我想在1个活动中制作3个微调器，每个活动包含数据取决于从前一个微调器中选择的项目 我的问题是我该怎么做？ 我希望默认项目填充取决于第一个微调器的第一个默认项目？

ListAdapter Adapter1 = new SimpleAdapter(this,
                List1,
                android.R.layout.simple_dropdown_item_1line,
                new String[] { "t1" }, new int[] { android.R.id.tx1 });
        s1.setAdapter((SpinnerAdapter) TypeArrayAdapter);

        s1.setOnItemSelectedListener(new OnItemSelectedListener() {

            @Override
            public void onItemSelected(AdapterView<?> arg0, View arg1,
                    int arg2, long arg3) {
                // TODO Auto-generated method stub
                str1 = s1.getSelectedItem();

            }

            @Override
            public void onNothingSelected(AdapterView<?> arg0) {
                // TODO Auto-generated method stub

            }

        });

                   getStr(str1);
        ListAdapter Adapter2 = new SimpleAdapter(this,
                List2,
                android.R.layout.simple_dropdown_item_1line,
                new String[] { "t2" }, new int[] { android.R.id.tx1 });
        s2.setAdapter((SpinnerAdapter) TypeArrayAdapter);

        s2.setOnItemSelectedListener(new OnItemSelectedListener() {

            @Override
            public void onItemSelected(AdapterView<?> arg0, View arg1,
                    int arg2, long arg3) {
                // TODO Auto-generated method stub
                str2 = s1.getSelectedItem();

            }

            @Override
            public void onNothingSelected(AdapterView<?> arg0) {
                // TODO Auto-generated method stub

            }

        });