android - Android使EditText再次可见和不可见

Question

我正在为赛艇运动员和桨手制作 Android 应用程序。有不同大小的船。就像只有一个桨手的 Kajak 和有 20 个桨手的龙舟。我正在尝试创建所有这些并仅显示我选择的典型船所需的那些。我的问题是我不能让微调器再次变得不可见和可见。我的代码是这样的：

public class DayTripActivity extends Activity {
    private boolean visible = true;
    @Override
    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        // setContentView(R.layout.day_trip);
        ScrollView scrollView = new ScrollView(this);

        final LinearLayout linearLayout = new LinearLayout(this);
        linearLayout.setOrientation(LinearLayout.VERTICAL); 
        scrollView.addView(linearLayout);
        this.setContentView(scrollView);

        for(int i = 0; i < 20; i++){
            TextView tvCrew = new TextView(this);
            tvCrew.setText("Crewmember "+i);
            tvCrew.setId(ID_Crew_TEXTVIEW+i);
            linearLayout.addView(tvCrew);
        }

        Button btndatePicker = new Button(this);
        btndatePicker.setText("Make Drummer 2 invisible / visible");
        btndatePicker.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View arg0) {
                if(visible){
                        linearLayout.findViewById(ID_DRUMMER_TEXTVIEW+1).setVisibility(View.VISIBLE);
                }else{
                    linearLayout.findViewById(ID_DRUMMER_TEXTVIEW+1).setVisibility(View.GONE);
                }
                visible = !visible;
            }
        });
        linearLayout.addView(btndatePicker);