java - SwitchCompat 无法与 firebase 数据库正常工作

Question

我的 android 项目中有 firebase 数据库，其中包含三个值:代码、电子邮件、日期。我正在使用 switchcompat 来统计 firebase 数据库中当前学生的数量。当检查开关时，数据将进入 firebase 数据库，检查电子邮件在特定日期是否唯一。当取消选中开关时，当前日期的数据将被删除。但我的问题是，当我第一次检查开关时，它工作正常。在取消选中开关一次后的第二次，当我再次检查它时，它会将数据输入到 firebase 中，但即使仍然选中开关，它也会立即自动删除它。我不明白我的代码中的问题出在哪里。 我在下面提供了用于 SwitchCompat 工作的代码。 这是代码:

switch1.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            Date c = Calendar.getInstance().getTime();
            SimpleDateFormat df = new SimpleDateFormat("dd-MMM-yyyy");
            final String date = df.format(c);
            Calendar cal = Calendar.getInstance();
            cal.add(Calendar.DATE, -1);
            final String previousDate = df.format(cal.getTime());
            final int[] i = {0};
            if (switch1.isChecked()) {
                Query equery = present.orderByChild("email").equalTo(email);
                equery.addValueEventListener(new ValueEventListener() {
                    @Override
                    public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                        if (!dataSnapshot.exists()) {
                            String code = "1";
                            PresentStu presentStu = new PresentStu(FirebaseAuth.getInstance().getCurrentUser().getEmail(), date, code);
                            String uploadId = present.push().getKey();
                            present.child(uploadId).setValue(presentStu);
                        } else {
                            for (DataSnapshot snapshot : dataSnapshot.getChildren()) {
                                String eemail = snapshot.child("email").getValue().toString();
                                String ddate = snapshot.child("date").getValue().toString();
                                if (eemail.equals(eemail) && ddate.equals(date)) {
                                    i[0]++;
                                    break;
                                }
                            }
                           // Toast.makeText(User.this,""+i[0]+"",Toast.LENGTH_SHORT).show();
                                if (i[0] < 1){
                                    String code = "1";
                                    PresentStu presentStu = new PresentStu(FirebaseAuth.getInstance().getCurrentUser().getEmail(), date, code);
                                    String uploadId = present.push().getKey();
                                    present.child(uploadId).setValue(presentStu);
                                }
                            }
                    }

                    @Override
                    public void onCancelled(@NonNull DatabaseError databaseError) {

                    }
                });
            } else {
                Query equery = present.orderByChild("email").equalTo(email);
                equery.addValueEventListener(new ValueEventListener() {
                    @Override
                    public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                        for (DataSnapshot snapshot : dataSnapshot.getChildren()) {
                            String eemail = snapshot.child("email").getValue().toString();
                            String ddate = snapshot.child("date").getValue().toString();
                            if (eemail.equals(eemail) && ddate.equals(previousDate)) {
                                present.child(dataSnapshot.getChildren().iterator().next().getKey()).child("code").setValue("0");
                            }
                            if (eemail.equals(eemail) && ddate.equals(date)) {
                                snapshot.getRef().removeValue();
                                break;
                            }
                        }

                    }

                    @Override
                    public void onCancelled(@NonNull DatabaseError databaseError) {

                    }
                });
            }
        }
    });

请帮我找出代码中的不足。

My database structure

Answer 1

因为我不知道您数据库的结构，所以您不能简单地复制/粘贴此 fragment ；这是您自己的代码，删除了事件监听器。

使用正确的方式获取快照的正确路径并直接进行更改，无需等待数据更改。

switch1.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            Date c = Calendar.getInstance().getTime();
            SimpleDateFormat df = new SimpleDateFormat("dd-MMM-yyyy");
            final String date = df.format(c);
            Calendar cal = Calendar.getInstance();
            cal.add(Calendar.DATE, -1);
            final String previousDate = df.format(cal.getTime());
            final int[] i = {0};
            if (switch1.isChecked()) {
                Query equery = present.orderByChild("email").equalTo(email);
                // TODO Change this:
                DataSnapshot dataSnapshot = equery.doSomethingToGettheSnapshot()

                        if (!dataSnapshot.exists()) {
                            String code = "1";
                            PresentStu presentStu = new PresentStu(FirebaseAuth.getInstance().getCurrentUser().getEmail(), date, code);
                            String uploadId = present.push().getKey();
                            present.child(uploadId).setValue(presentStu);
                        } else {
                            for (DataSnapshot snapshot : dataSnapshot.getChildren()) {
                                String eemail = snapshot.child("email").getValue().toString();
                                String ddate = snapshot.child("date").getValue().toString();
                                if (eemail.equals(eemail) && ddate.equals(date)) {
                                    i[0]++;
                                    break;
                                }
                            }
                           // Toast.makeText(User.this,""+i[0]+"",Toast.LENGTH_SHORT).show();
                                if (i[0] < 1){
                                    String code = "1";
                                    PresentStu presentStu = new PresentStu(FirebaseAuth.getInstance().getCurrentUser().getEmail(), date, code);
                                    String uploadId = present.push().getKey();
                                    present.child(uploadId).setValue(presentStu);
                                }
                            }
                    }

            } else {
                Query equery = present.orderByChild("email").equalTo(email);

                // TODO Change this:
                DataSnapshot dataSnapshot = equery.doSomethingToGettheSnapshot()

                        for (DataSnapshot snapshot : dataSnapshot.getChildren()) {
                            String eemail = snapshot.child("email").getValue().toString();
                            String ddate = snapshot.child("date").getValue().toString();
                            if (eemail.equals(eemail) && ddate.equals(previousDate)) {
                                present.child(dataSnapshot.getChildren().iterator().next().getKey()).child("code").setValue("0");
                            }
                            if (eemail.equals(eemail) && ddate.equals(date)) {
                                snapshot.getRef().removeValue();
                                break;
                            }
                        }

                    }
            }
        }
    });