java如何根据微调器中选定的整数创建动态文本视图？

Question

03-05 11:31:07.042 1897-1897/com.example.project.a D/AndroidRuntime﹕ Shutting down VM --------- beginning of crash 03-05 11:31:07.050 1897-1897/com.example.project.a E/AndroidRuntime﹕ FATAL

EXCEPTION: main Process: com.example.project.a, PID: 1897 java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.project.a/com.example.project.a.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void 安卓.widget.LinearLayout.removeAllViews()' on a null object reference at 安卓.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298) at 安卓.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)

---

已选择公共视图（AdapterView arg0、视图arg1、内部arg2、长arg3）{

        //   Toast.makeText(getApplicationContext(),"The day qqq"+arg0.getItemAtPosition(arg2).toString(),Toast.LENGTH_LONG).show();
        String control2=arg0.getItemAtPosition(arg2).toString();

       int  noOfBulb= (int) spinner1.getSelectedItem();
        final TextView tryText2=(TextView)findViewById(R.id.textView);
        tryText2.setText("No"+noOfBulb);

        mdynamiclayout = (LinearLayout) findViewById(R.id.dynamiclayout);
        mdynamiclayout.removeAllViews();//need to remove the view before it create
        for (int i = 0; i < noOfBulb; i++) {//6 is your selected item from spinner it can be any nymber
            TextView t = new TextView(MainActivity.this);
            t.setText("value" + i);
            //  t.setTextSize(20);
            //  t.setTextColor(Color.BLUE);
            mdynamiclayout.addView(t);
        }

    }

    public  void onNothingSelected(AdapterView<?> arg0){}

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


    rl = (RelativeLayout) findViewById(R.id.rl);

    tv1 = new TextView (MainActivity.this);


    tv1.setText("Dynamic TextView");


    tv1.setTextColor(Color.RED);


    tv1.setTextSize(20);


    RelativeLayout.LayoutParams params1=new RelativeLayout.LayoutParams
            ((int)LayoutParams.WRAP_CONTENT,(int)LayoutParams.WRAP_CONTENT);
    params1.leftMargin=115;
    params1.topMargin=120;



   rl.addView(tv1);

---

public class Unit {
    private  String  _bulbNo;

    public  Unit(String bulbNo) {

        _bulbNo = bulbNo;


    }
    public  String getBulbNo(){
        return  _bulbNo;
    }

}
// I created this class


 private  void addBulbsFans(String bulb)
    {
        Units.add(new Unit(bulb));
    }

//我将此方法添加到MainActivity。JAVA在此之后，我需要知道如何从buttonclick事件传递微调器值

Answer 1

您可以简单地将所选字符串转换为整数，方法如下

 int value = Integer.valueOf(spiner.getselecteditem);