Question

我有3个微调器，当第一个微调器更新时，第二个和第三个微调器应该更新，但只有第二个微调器正在更新。这两个检查确实打印到logcat，但第三个微调器没有被更新。如果我注释掉spinner2.setAdapter（），那么第三个微调器将更新。如果我更改顺序，那么第一个微调器应该先更新，然后第二个微调器仍然更新而第三个微调器不会更新。我哪里错了？

我正在使用以下代码：

spinner1.setOnItemSelectedListener(new OnItemSelectedListener() 
    {
        @Override
        public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2, long arg3) 
        {
            pos = arg2;

            switch(pos)
            {
            case 0:
                allDepts.setDropDownViewResource(R.layout.multiline_spinner_dropdown_item);
                spinner2.setAdapter(allDepts);
                allCourses.setDropDownViewResource(R.layout.multiline_spinner_dropdown_item);
                spinner3.setAdapter(allCourses);                    
                break;
            case 1:
                AEDepartments.setDropDownViewResource(R.layout.multiline_spinner_dropdown_item);
                AEDepartments.notifyDataSetChanged();
                spinner2.setAdapter(AEDepartments);
                Log.v("Spinner check", "Department check."); 

                AECourses.setDropDownViewResource(R.layout.multiline_spinner_dropdown_item);
                AECourses.notifyDataSetChanged(); 
                spinner3.setAdapter(AECourses);
                Log.v("Spinner check", "Course check.");
                break;
            }
        }

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

编辑：因此，当应用程序加载时，它将显示“请选择学校”，它将显示所有部门和课程。当我点击第一个微调器并将其更改为“School 1”时。 spinner2应该更新为仅显示学校1中的部门（AEDepartments arrayadapter中的内容）和spinner3应该更新，因此只显示学校1中的课程（AECourses arrayadapter中的内容）。

@Override
public void onCreate(Bundle savedInstanceState) 
{       
    super.onCreate(savedInstanceState);
    setContentView(R.layout.student1);

    spinner1 = (Spinner)this.findViewById(R.id.school);
    spinner2 = (Spinner)this.findViewById(R.id.dept);
    spinner3 = (Spinner)this.findViewById(R.id.course);

    ArrayAdapter<School> allSchools = new ArrayAdapter<School>(this,
            android.R.layout.simple_spinner_item, new School[] {    
            new School("","-- Please Select School --"),
            new School("A","School 1"),
            new School("B","School 2"),
            new School("C","School 3")
    });

    allSchools.setDropDownViewResource(R.layout.multiline_spinner_dropdown_item);

    spinner1.setAdapter(allSchools);
    spinner1.setOnItemSelectedListener(this);       

    final ArrayAdapter<School> allDepts = new ArrayAdapter<School>(this,
            android.R.layout.simple_spinner_item, new School[] {    
            new School("","-- Please Select Department --"),
            new School("1","Dep1"),
            new School("2","Dep2"),
            new School("3","Dep3"),
            new School("4","Dep4")
    });

    allDepts.setDropDownViewResource(R.layout.multiline_spinner_dropdown_item);
    spinner2.setAdapter(allDepts);
    spinner2.setOnItemSelectedListener(this);         

    final ArrayAdapter<School> allCourses = new ArrayAdapter<School>(this,
            android.R.layout.simple_spinner_item, new School[] {
            new School("","-- Please Select Course --"),
            new School("C1","Couyrse1"),
            new School("C2","Couyrse2"),
            new School("C3","Couyrse3"),
            new School("C4","Couyrse4")
    });
    allCourses.setDropDownViewResource(R.layout.multiline_spinner_dropdown_item);       
    spinner3.setAdapter(allCourses);
    spinner3.setOnItemSelectedListener(this); 



    //Displaying all the departments in School 1
    final ArrayAdapter<School> AEDepartments = new ArrayAdapter<School>(this,
            android.R.layout.simple_spinner_item, new School[] {    
            new School("","-- Please Select Department --"),
            new School("1","Dep1"),
            new School("3","Dep3")
    }); 

    //Displaying all the courses in School 1
    final ArrayAdapter<School> AECourses = new ArrayAdapter<School>(this,
            android.R.layout.simple_spinner_item, new School[] {    
            new School("","-- Please Select Course --"),
            new School("C1","Couyrse1"),
            new School("C3","Couyrse3")
    }); 


    spinner1.setOnItemSelectedListener(new OnItemSelectedListener() 
    {
        @Override
        public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2, long arg3) 
        {
            pos = arg2;

            switch(pos)
            {
            case 0:
                allDepts.setDropDownViewResource(R.layout.multiline_spinner_dropdown_item);
                allCourses.setDropDownViewResource(R.layout.multiline_spinner_dropdown_item);
                spinner2.setAdapter(allDepts);
                spinner3.setAdapter(allCourses);                
                Log.v("Spinner check", "Department check.");
                Log.v("Spinner check", "Course check.");
                break;

            case 1:
                AEDepartments.setDropDownViewResource(R.layout.multiline_spinner_dropdown_item);
                AEDepartments.notifyDataSetChanged();
                spinner2.setAdapter(AEDepartments);
                Log.v("Spinner check", "Department check."); 

                AECourses.setDropDownViewResource(R.layout.multiline_spinner_dropdown_item);
                AECourses.notifyDataSetChanged(); 
                spinner3.setAdapter(AECourses);
                Log.v("Spinner check", "Course check.");
                break;
            }
        }
        @Override
        public void onNothingSelected(AdapterView<?> arg0) 
        {
        }
    });
}

Answer 1

我解决了我的问题！当我设置spinner2和spinner3来改变值时，spinner2.setOnItemSelectedListener（）也改变了spinner3值（当我自己在spinner2上选择一个值时，它应该只会改变）。所以spinner2过度写了我在spinner1中设置它的内容。我添加一个if语句并修复它。

Answer 2

我通过聚焦edittext解决了这个问题。 edittext.requestfocus()，这使得fragmet专注于UI并更新值。

Spinner不会更新

2 个答案: