chatTool

使用firebase技術做出的一個聊天室小工具，並有以下特點

．使用GMail即可登入．使用人數無上限．可更換自己的大頭貼．即時的通訊功能，可輸入文字、圖片訊息

一、使用前需先至Firebase平台註冊登入，網址為：https://console.firebase.google.com

二、將Firebase工具導入gradle中

implementation 'com.android.support:design:28.0.0'
implementation 'com.firebaseui:firebase-ui:1.1.1'

implementation 'com.google.firebase:firebase-database:17.0.0'
implementation 'com.google.firebase:firebase-core:16.0.9'
implementation 'com.google.firebase:firebase-auth:16.0.1'

// FirebaseUI for Cloud Firestore
implementation 'com.firebaseui:firebase-ui-firestore:5.0.0'
// FirebaseUI for Firebase Auth
implementation 'com.firebaseui:firebase-ui-auth:5.0.0'
// FirebaseUI for Cloud Storage
implementation 'com.firebaseui:firebase-ui-storage:5.0.0'

三、登入動作

MainActivity.java

if (FirebaseAuth.getInstance().getCurrentUser() == null) {
            startActivityForResult(AuthUI.getInstance().createSignInIntentBuilder().build(), SIGN_IN_REQUEST);
}

使用AuthUI工具取得實體後，建立SignIn動作並回傳結果至Activity中

四、登出動作

AuthUI.getInstance().signOut(this)
                .addOnCompleteListener(new OnCompleteListener<Void>() {
                    @Override
                    public void onComplete(@NonNull Task<Void> task) {
                        Toast.makeText(MainActivity.this, "sighOut", Toast.LENGTH_SHORT).show();
                        finish();
                    }
                });

一樣使用AuthUI工具取得實體，呼叫SignOut方法，並加上listener完成登出後的動作

五、發送消息至平台

1、取得FirebaseDatabase實體

reference = FirebaseDatabase.getInstance().getReference();

2、自定義model

public class ChatMessage {

private String userName;//使用者名稱
private String message;//訊息內容
private long time;//發送時間

public ChatMessage(String userName, String message) {
    this.userName = userName;
    this.message = message;
    time = new Date().getTime();
}

3、發送消息

try {
                reference.push()
                        .setValue(new ChatMessage(
                                FirebaseAuth.getInstance().getCurrentUser().getDisplayName(),
                                edtInput.getText().toString()));

                edtInput.setText("");
                imm.hideSoftInputFromWindow(v.getWindowToken(), 0);//送出後鍵盤收起
            }catch (Exception e){
                e.printStackTrace();
            }

六、接收Firebase平台訊息

1、建立ChatMessageViewHolder

public class ChatMessageHolder extends RecyclerView.ViewHolder {
    private TextView txvUser;
    private TextView txvMsg;
    private TextView txvTime;

    public ChatMessageHolder(@NonNull View v) {
        super(v);
        txvUser = (TextView) v.findViewById(R.id.txv_user);
        txvMsg = (TextView) v.findViewById(R.id.txv_msg);
        txvTime = (TextView) v.findViewById(R.id.txv_time);

    }

    public void setValues(ChatMessage chatMessage) {
        txvUser.setText(chatMessage.getUserName());
        txvMsg.setText(chatMessage.getMessage());
        txvTime.setText(DateFormat.format("yyyy-MM-dd (HH:mm:ss)", chatMessage.getTime()));

    }
}

2' 建立FirebaseRecyclerAdapter

displayChatMsg()中

    try {
        
        adapter = new FirebaseRecyclerAdapter<ChatMessage, ChatMessageHolder>
                (ChatMessage.class, R.layout.message, ChatMessageHolder.class, reference.limitToLast(10)) {

            public ChatMessageHolder onCreateViewHolder(ViewGroup parent, int viewType) {
                View view = LayoutInflater.from(MainActivity.this).inflate(R.layout.message, parent, false);
                ChatMessageHolder holder = new ChatMessageHolder(view);
                return holder;
            }

            @Override
            protected void populateViewHolder(ChatMessageHolder viewHolder, ChatMessage model, int position) {
                    viewHolder.setValues(model);

            }
        };

ps：reference.limitToLast(10) → 抓取Firebase的最新10筆資料

七、設置adapter

recyclerView.setAdapter(adapter);

LucaLin/chatTool

chatTool