Question

任何人都可以帮助我吗？

spinner2没有显示所选位置，其中必须使用Toast（代码下方）显示。

我无法找到我的代码有什么问题。非常感谢您的回复。谢谢。

<Spinner
   android:id="@+id/spinner2"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_weight="5.67"
    android:entries="@array/groupLamp />

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        /*parameters*/
        final Integer incandescant[]={5,15,25,35,40,60,75,100,125,150};
        final Integer led[] = {0,2,3,5,8,13,15,20,23,28};
        final Integer cfl[] = {0,0,0,0,13,15,25,30,40,45};
        final Integer fluorescent[] = {40,40,20,55};

        Button btnCalc = (Button) findViewById(R.id.btnCalculate);
        Spinner spinner1 = (Spinner) findViewById(R.id.spinner1);
        final Spinner spinner2 = (Spinner) findViewById(R.id.spinner2);

        List<String> list = new ArrayList<String>();
        list.add("Incandescant");
        list.add("CFL");
        list.add("Flourescent");
        list.add("Others");

        final List<String> list2 = new ArrayList<String>();
        final List<String> list3 = new ArrayList<String>();

        ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item,list);
        dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spinner1.setAdapter(dataAdapter);

        spinner1.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {

            public void onItemSelected(AdapterView<?> parent, View view, int pos, long id) {
                list2.clear();

                if(pos==0){
                    for(Integer ctr: incandescant){
                        list2.add(ctr+ " watts");
                    }

                }else if(pos==1){
                    for(Integer ctr: led){
                        list2.add(ctr +" watts");
                    }
                }
            }
            public void onNothingSelected(AdapterView<?> parent) {
            }
        });

        ArrayAdapter<String> dataAdapter2 = new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item,list2);
        dataAdapter2.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spinner2.setAdapter(dataAdapter2);
        spinner2.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            public void onItemSelected(AdapterView<?> parent, View view, int pos, long id) {

                Toast.makeText(MainActivity.this, ""+pos, Toast.LENGTH_LONG).show();
            }
            public void onNothingSelected(AdapterView<?> parent) {
            }
        });

    }

Answer 1

看起来很奇怪 - 您在XML中的spinner的1 ID是spinner2，但在代码中您引用的是spnExistLamp和spnElampWat。因此，XML和代码之间没有任何联系。

Answer 2

确保您正确链接xml中的视图。

xml中的

android:id="@+id/spinner2"

但是在你的代码中你正在使用

Spinner spinner1 = (Spinner) findViewById(R.id.spnExistLamp);
final Spinner spinner2 = (Spinner) findViewById(R.id.spnElampWat);

Plz在您的代码中进行以下更改

final List<String> list2 = new ArrayList<String>();
final ArrayAdapter<String> dataAdapter2 = new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item,list2);  //------ line location changed.

spinner1.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {

            public void onItemSelected(AdapterView<?> parent, View view, int pos, long id) {
                list2.clear();

                if(pos==0){
                    for(Integer ctr: incandescant){
                        list2.add(ctr+ " watts");
                    }

                }else if(pos==1){
                    for(Integer ctr: led){
                        list2.add(ctr +" watts");
                    }
                }

                dataAdapter2.notifyDataSetChanged();    //------- line added
            }
            public void onNothingSelected(AdapterView<?> parent) {
            }
        });

Android - 微调器选定的项目未被侦听器检测到

2 个答案: