Android 点击按钮从firebase数据库检索数据,这些数据以列表格式以其他活动显示
我的班级 包com.example.shikshaMela.sm 公共课{Android 点击按钮从firebase数据库检索数据,这些数据以列表格式以其他活动显示,android,firebase,firebase-realtime-database,Android,Firebase,Firebase Realtime Database,我的班级 包com.example.shikshaMela.sm 公共课{ public class HomeActivity extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstance
public class HomeActivity extends AppCompatActivity
implements NavigationView.OnNavigationItemSelectedListener {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home);
Button ten, twelve;
ten=(Button) findViewById(R.id.tenth) ;
twelve=(Button) findViewById(R.id.twelth) ;
ten.setOnClickListener(new View.OnClickListener() {
DatabaseReference ref = FirebaseDatabase.getInstance().getReference().child("Customer_details");
@Override
public void onClick(View v) {
}
});
}
}
`我想从数据库中获取所有课程列表(如bca),并将其显示在其他活动的列表中。这些项目(bca)是可点击的,因此,当我们点击这些项目(bca)时,就会获取其内部数据(如大学资格等)
我该怎么做
//参考-->您的数据库参考
请参阅.addListenerForSingleValueEvent(新的ValueEventListener()){
@凌驾
公共void onDataChange(DataSnapshot DataSnapshot){
迭代器dataSnapshotsChat=dataSnapshot.getChildren().Iterator();
User=null;//用户是模型类
while(dataSnapshotsChat.hasNext()){
DataSnapshot dataSnapshotChild=dataSnapshotsChat.next();
user=dataSnapshotChild.getValue(user.class);
如果(!Lists.contains(user.id)){//这里的List是user类型的数组列表
列表。添加(用户);
}
}
})创建模型类并存储结果是模型类型的arraylist,当您单击任何项时,只需从arraylist传递该项。我创建了类,但我搞不清楚它是否正确,或者当我们要将数据存储在数组列表中时,会出现很多错误,如果您给进程将数据存储在数组列表中并从数组列表传递项en i thakfulref.addListenerForSingleValueEvent(新值EventListener(){@Override public void onDataChange(DataSnapshot DataSnapshot){Iterator DataSnapshot=DataSnapshot.getChildren().Iterator();课程详细信息课程=null;而(dataSnapshotsChat.hasNext()){DataSnapshot dataSnapshotChild=datasnapshotsourse_tenth.next();课程详细信息=dataSnapshotChild.getValue(课程详细信息.class);if(!Lists.contains(课程详细信息.Course_tenth)){Lists.add(课程详细信息);}这不是工作这么多的错误显示,导入迭代器,arraylist,valueevent侦听器类只是导入类。并发送你的refi不知道你想说什么
String name = "";
String college_list = "";
String fee = "";
String duration = "";
String higher_study = "";
String job_aspects = "";
String entrance_exam = "";
public course_tenth() {
}
public course_tenth(String name, String college_list, String fee, String duration, String higher_study, String job_aspects, String entrance_exam)
{
this.name = name;
this.college_list = college_list;
this.fee = fee;
this.duration = duration;
this.higher_study = higher_study;
this.job_aspects = job_aspects;
this.entrance_exam = entrance_exam;
}
public String getname() {
return name;
}
public String getCollege_list() {
return college_list;
}
public String getFee() {
return fee;
}
public String getDuration() {
return duration;
}
public String getHigher_study() {
return higher_study;
}
public String getJob_aspects() {
return job_aspects;
}
public String getEntrance_exam() {
return entrance_exam;
}
// refer --> your DatabaseReference
refer.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
Iterator<DataSnapshot> dataSnapshotsChat = dataSnapshot.getChildren().iterator();
User user = null; // User is Model class
while (dataSnapshotsChat.hasNext()) {
DataSnapshot dataSnapshotChild = dataSnapshotsChat.next();
user = dataSnapshotChild.getValue(User.class);
if (!Lists.contains(user.id)) { // here List is array list of type User
Lists.add(user);
}
}