Android开发入门指导代码示例

（示例代码）

public class MainActivity extends AppCompatActivity {
    private static final int PICK_CONTACT_REQUEST = 0;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Register a key event listener to handle the DPAD center button press.
        registerKeyListener(new OnKeyDownListener() {
            @Override
            public boolean onKeyDown(int keyCode, KeyEvent event) {
                if (keyCode == KeyEvent.KEYCODE_DPAD_CENTER) {
                    // When user presses DPAD center, initiate contact selection.
                    Intent intent = new Intent(Intent.ACTION_PICK, Uri.parse(\"content://contacts\"));
                    startActivityForResult(intent, PICK_CONTACT_REQUEST);
                    return true;
                }
                return false;
            }
        });
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == PICK_CONTACT_REQUEST && resultCode == RESULT_OK) {
            // A contact has been selected. Display the chosen contact details to the user.
t            Intent viewContactIntent = new Intent(Intent.ACTION_VIEW, data.getData());
            startActivity(viewContactIntent);
        }
    }
}