android - 如何使用微调器

Question

我是 android 的新手。 I want to use 2 spinners in my application, one shows the countries list, when any country is selected the other spinner should show the list of cities of that country.选择城市后，将执行一些操作。请帮我一些示例代码。感谢期待

Answer 1

这是我们可以用来向 spinner2 w.r.t 添加选项到 spinner 1 的东西。

public class Activity extends Activity implements View.OnClickListener
{
    private Spinner spinner0, spinner1, spinner2, spinner3;
    private Button submit, cancel;

    private String country[], state[], city[], area[];

    Australia aus = new Australia();

    Object object;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        spinner0 = (Spinner)findViewById(R.id.spinnerCountry);
        spinner1 = (Spinner)findViewById(R.id.spinnerQ1);
        spinner2 = (Spinner)findViewById(R.id.spinnerQ2);
        spinner3 = (Spinner)findViewById(R.id.spinnerQ3);

        submit = (Button)findViewById(R.id.btnSubmit);
        cancel = (Button)findViewById(R.id.btnCancel);

        submit.setOnClickListener(this);
        cancel.setOnClickListener(this);

        country = new String[] {"Select Country", "Australia", "USA", "UK", "New Zealand", "EU", "Europe", "China", "Hong Kong",
                                "India", "Malaysia", "Canada", "International", "Asia", "Africa"};


        ArrayAdapter<String> adapter0 = new ArrayAdapter<String>(Activity.this, android.R.layout.simple_spinner_item, country);
        adapter0.setDropDownViewResource(android.R.layout.simple_dropdown_item_1line);
        spinner0.setAdapter(adapter0);
        Log.i("AAA","spinner0");

        spinner0.setOnItemSelectedListener(new OnItemSelectedListener()
        {           
            @Override
            public void onItemSelected(AdapterView<?> arg0, View view1, int pos, long id)
            {
                Log.i("AAA","OnItemSelected");
                int loc;
                loc = pos;

                switch (loc)
                {
                case 1:

                    state = aus.getState();
                    object = aus;

                    Log.i("AAA","ArrayAdapter1");                   
                    ArrayAdapter<String> adapter1 = new ArrayAdapter<String>(Activity.this, android.R.layout.simple_spinner_item, state);
                    adapter1.setDropDownViewResource(android.R.layout.simple_dropdown_item_1line);
                    spinner1.setAdapter(adapter1);          Log.i("AAA","spinner1");
                    break;

                default:
                    Log.i("AAA","default 0");
                    break;
                }                               
            }       

            @Override
            public void onNothingSelected(AdapterView<?> arg1)
            {
                Log.i("AAA","Nothing S0");

            }
        });

       spinner1.setOnItemSelectedListener(new OnItemSelectedListener()
       {
            @Override
            public void onItemSelected(AdapterView<?> arg0, View view1, int pos, long id) 
            {
                Log.i("AAA","OnItemSelected S1");
                int loc = pos;
                switch(loc)
                {
                    case 1:
                        Log.i("AAA","Australia");
                        if(object.equals(aus))
                        {
                            city = aus.getType(loc);
                        }
                        else
                        {
                            break;
                        }


                        ArrayAdapter<String> adapter = new ArrayAdapter<String>(Activity.this, android.R.layout.simple_spinner_item, city);
                        adapter.setDropDownViewResource(android.R.layout.simple_dropdown_item_1line);
                        spinner2.setAdapter(adapter);           Log.i("AAA","spinner2");
                        break;

                    default:
                            Log.i("AAA", "default 1");
                        break;

                }
            }
            @Override
            public void onNothingSelected(AdapterView<?> arg0)
            {
                Log.i("AAA","Nothing S1");              
            }

        }); 

       spinner2.setOnItemSelectedListener(new OnItemSelectedListener()
       {

        @Override
        public void onItemSelected(AdapterView<?> arg0, View arg1, int pos, long id)
        {
            int loc = pos;
            switch (loc)
            {
            case 1:
                if(object.equals(aus))
                {
                    area = aus.getTitle(loc);
                }

                ArrayAdapter<String> adapter = new ArrayAdapter<String>(Activity.this, android.R.layout.simple_spinner_item, area);
                adapter.setDropDownViewResource(android.R.layout.simple_dropdown_item_1line);
                spinner3.setAdapter(adapter);           Log.i("","spinner3");               
                break;

            default:
                break;
            }

        }

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

    }// on-create


    @Override
    public void onClick(View v)
    {
        switch (v.getId())
        {
        case R.id.btnSubmit:

            break;

        case R.id.btnCancel:
            finish();
            break;

        default:
            break;
        }       
    }   
}

如果您觉得有用，请投上一票，以便其他人轻松找到好的答案。

对于每个国家/地区，您必须为其创建一个类，以仅添加州、城市和地区。这样它就不会变成单个页面上的网格。

玩得开心。

问候，

也许吧。