Android/UIプルダウン

プルダウンサンプル

MainActivity.java

        ArrayAdapter<String> adapter = new ArrayAdapter<>(
                this,
                android.R.layout.simple_spinner_item,
                new String[] {
                        "test1",
                        "test2",
                        "test3",
                        "test4"}
        );
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        Spinner spinner = findViewById(R.id.sizelist);
        spinner.setAdapter(adapter);
        spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent,
                                       View view, int position, long id) {
                Spinner spinner = (Spinner)parent;
                String item = (String)spinner.getSelectedItem();
                //textView.setText(item);
            }
            public void onNothingSelected(AdapterView<?> parent) {
                //
            }
        });

main_activity.xml

            <Spinner
                android:id="@+id/sizelist"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginRight="5dp"
                android:layout_marginLeft="5dp"
                />

参考：http://d.hatena.ne.jp/nkawamura/20131005/1380963701