如何将Firebase数据库中的多个图像添加到ArrayList中 [英] How do i add multiple Images from my Firebase Database to my ArrayList

问题描述

public class getFirebase extends AppCompatActivity {

    DatabaseReference dbRef;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_get_firebase);

        dbRef = FirebaseDatabase.getInstance().getReference().child("theimage");

        final List<Integer> images = new ArrayList<>();

        dbRef.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull com.google.firebase.database.DataSnapshot dataSnapshot) {

            }

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

            }
        })

    }
}

我已将图像上传到我的Firebase存储，然后将图像链接复制到我的数据库子代"theimage".请参考上传的图片.

I have uploaded the images to my firebase Storage and then copied the image link to my database child "theimage". Refer uploaded Image.

在"theimage"节点内放置图​​像存储链接

put images storage link inside "theimage" node

您认为将所有图像从Firebase数据库获取到ArrayList的最佳方法是什么?

What do you think is the best way to get all the images from my firebase Database to my ArrayList?

推荐答案

您必须遍历DataSnapshot才能将所有图像放入ArrayList.除此之外，您的ArrayList应该是String类型.检查以下内容:

You have to loop through your DataSnapshot to get all the images into ArrayList. Beside this your ArrayList should be String type. Check below:

final List<String> images = new ArrayList<>();

dbRef.addValueEventListener(new ValueEventListener() {
    @Override
    public void onDataChange(@NonNull DataSnapshot dataSnapshot) {

        for(DataSnapshot childSnapshot: dataSnapshot.getChildren()) {
            images.add(childSnapshot.getValue(String.class));
        }
    }

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

    }
});

如果您还想获取 apple ， samsung 之类的密钥，则必须使用Map而不是ArrayList.检查以下内容:

If you also want to get the key like apple, samsung then you have to use Map instead of ArrayList. check below:

final Map<String, String> images = new HashMap<>();

dbRef.addValueEventListener(new ValueEventListener() {
    @Override
    public void onDataChange(@NonNull DataSnapshot dataSnapshot) {

        for(DataSnapshot childSnapshot: dataSnapshot.getChildren()) {
            images.put(childSnapshot.getKey(), childSnapshot.getValue(String.class));
        }
    }

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

    }
});

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