Java “我的微调器”在添加从firebase数据库中选择的多个值时被覆盖
我想从courseName获取所有值,并使用它填充微调器:Java “我的微调器”在添加从firebase数据库中选择的多个值时被覆盖,java,android,android-spinner,Java,Android,Android Spinner,我想从courseName获取所有值,并使用它填充微调器: databaseReference.addChildEventListener(new ChildEventListener() { @Override public void onChildAdded(DataSnapshot dataSnapshot, String s) { final List<String> courses = new ArrayList<String>(); f
databaseReference.addChildEventListener(new ChildEventListener() {
@Override
public void onChildAdded(DataSnapshot dataSnapshot, String s) {
final List<String> courses = new ArrayList<String>();
for (DataSnapshot courseSnapshot: dataSnapshot.getChildren())
{
String courseName = courseSnapshot.getValue(String.class);
courses.add(courseName);
}
Spinner spinnerCourse = findViewById(R.id.spinnerCourse);
ArrayAdapter<String> courseAdapter = new ArrayAdapter<String>(AddSubject.this,android.R.layout.simple_spinner_item, courses);
courseAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinnerCourse.setAdapter(courseAdapter);
}
}
databaseReference.addChildEventListener(新的ChildEventListener()){
@凌驾
公共void onChildAdded(DataSnapshot DataSnapshot,字符串s){
最终列表课程=新的ArrayList();
对于(DataSnapshot课程snapshot:DataSnapshot.getChildren())
{
String courseName=courseSnapshot.getValue(String.class);
添加(courseName);
}
喷丝器喷丝头层=FindViewByd(R.id.喷丝头层);
ArrayAdapter courseAdapter=新的ArrayAdapter(AddSubject.this,android.R.layout.simple\u spinner\u项目,courses);
CourseApter.setDropDownViewResource(android.R.layout.simple\u微调器\u下拉菜单\u项);
喷丝头固定接头(固定接头);
}
}
您需要先清除列表,然后使用下面的clear()
方法将其绑定
databaseReference.addChildEventListener(new ChildEventListener() {
@Override
public void onChildAdded(DataSnapshot dataSnapshot, String s)
{
final List<String> courses = new ArrayList<String>();
courses.clear();
for (DataSnapshot courseSnapshot: dataSnapshot.getChildren())
{
String courseName = courseSnapshot.getValue(String.class);
courses.add(courseName);
}
Spinner spinnerCourse = findViewById(R.id.spinnerCourse);
ArrayAdapter<String> courseAdapter = new ArrayAdapter<String>(AddSubject.this,android.R.layout.simple_spinner_item, courses);
courseAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinnerCourse.setAdapter(courseAdapter);
}
}
databaseReference.addChildEventListener(新的ChildEventListener()){
@凌驾
公共void onChildAdded(DataSnapshot DataSnapshot,字符串s)
{
最终列表课程=新的ArrayList();
课程。清晰();
对于(DataSnapshot课程snapshot:DataSnapshot.getChildren())
{
String courseName=courseSnapshot.getValue(String.class);
添加(courseName);
}
喷丝器喷丝头层=FindViewByd(R.id.喷丝头层);
ArrayAdapter courseAdapter=新的ArrayAdapter(AddSubject.this,android.R.layout.simple\u spinner\u项目,courses);
CourseApter.setDropDownViewResource(android.R.layout.simple\u微调器\u下拉菜单\u项);
喷丝头固定接头(固定接头);
}
}