我是Android开发新手并且正在使用Android Studio。我正在尝试构建一个基本的聊天应用程序。
我的ChatActivity.java的内容是：
public class ChatActivity extends AppCompatActivity implements View.OnClickListener {
private ListView mDrawerList;
private ArrayAdapter<String> mAdapter;
private EditText msg_edittext;
private String user1 = "anaviltripathi", user2 = "cmaria";
private Random random;
ListView msgListView;
public static ChatAdapter chatAdapter;
public static ArrayList<ChatMessage> chatlist;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_chat);
mDrawerList = (ListView)findViewById(R.id.navList);
Intent intent = getIntent();
Bundle extras = intent.getExtras();
String channel_name = extras.getString("CHANNEL_NAME");
Log.i("ChannelListActivity", channel_name);
this.setTitle(channel_name);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
// Show the Up button in the action bar.
ActionBar actionBar = getSupportActionBar();
if (actionBar != null) {
actionBar.setDisplayHomeAsUpEnabled(true);
}
//
LayoutInflater inflater = (LayoutInflater) this.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
ViewGroup container = (ViewGroup)findViewById(R.id.msgListView);
// getSupportActionBar().setDisplayHomeAsUpEnabled(true);
// getSupportActionBar().setHomeButtonEnabled(true);
// To make the navigation bar items clickable
// mDrawerList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
// @Override
// public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
// Toast.makeText(MainActivity.this, "Time for an upgrade!", Toast.LENGTH_SHORT).show();
// }
// });
// ListView item = (ListView) findViewById(R.id.msgListView);
// View child = getLayoutInflater().inflate(R.layout.chat_bubble_left, null);
// item.addFooterView(child);
View view = inflater.inflate(R.layout.activity_chat, container, false);
random = new Random();
msg_edittext = (EditText) view.findViewById(R.id.messageEditText);
msgListView = (ListView) view.findViewById(R.id.msgListView);
ImageButton sendButton = (ImageButton) view
.findViewById(R.id.sendMessageButton);
// sendButton.setOnClickListener(this);
// ----Set autoscroll of listview when a new message arrives----//
msgListView.setTranscriptMode(ListView.TRANSCRIPT_MODE_ALWAYS_SCROLL);
msgListView.setStackFromBottom(true);
chatlist = new ArrayList<ChatMessage>();
chatlist.add(new ChatMessage(user1, user2, "YO", "1", true));
chatlist.add(new ChatMessage(user2, user1, "YO", "2", false));
chatlist.add(new ChatMessage(user1, user2, "BRO", "3", true));
chatAdapter = new ChatAdapter(container.getContext(), R.layout.chat_bubble_left, chatlist);
msgListView.setAdapter(chatAdapter);
chatAdapter.add(new ChatMessage(user2, user1, "BRuuuuuuuuuuu", "4", true));
chatAdapter.notifyDataSetChanged();
Log.d("chatActivityLog", "coming to onCreate");
}
private void addDrawerItems() {
String[] osArray = { "Android", "iOS", "Windows", "OS X", "Linux" };
mAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, osArray);
mDrawerList.setAdapter(mAdapter);
}
public void sendTextMessage(View v) {
String message = msg_edittext.getEditableText().toString();
if (!message.equalsIgnoreCase("")) {
final ChatMessage chatMessage = new ChatMessage(user1, user2,
message, "" + random.nextInt(1000), true);
chatMessage.setMsgID();
chatMessage.body = message;
chatMessage.Date = CommonMethods.getCurrentDate();
chatMessage.Time = CommonMethods.getCurrentTime();
msg_edittext.setText("");
chatAdapter.add(chatMessage);
chatAdapter.notifyDataSetChanged();
}
}
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.sendMessageButton:
// sendTextMessage(v);
}
chatAdapter.notifyDataSetChanged();
}
}
ChatAdapter.java的内容是：
public class ChatAdapter extends ArrayAdapter {
private static LayoutInflater inflater = null;
ArrayList<ChatMessage> chatMessageList;
public ChatAdapter(Context context, int textViewResourceId, ArrayList<ChatMessage> list) {
super(context,textViewResourceId);
chatMessageList = list;
Log.d("ChatAdapter", "comes to constructor");
}
@Override
public int getCount() {
Log.d("chatAdaptergetCount", "size: "+chatMessageList.size());
return chatMessageList.size();
}
@Override
public ChatMessage getItem(int position) {
return this.chatMessageList.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
inflater = (LayoutInflater) this.getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
Log.d("chatAdaptergetView", "coming bro");
ChatMessage message = (ChatMessage) chatMessageList.get(position);
View vi = convertView;
if (convertView == null)
vi = inflater.inflate(R.layout.chat_bubble_left, parent, false);
TextView msg = (TextView) vi.findViewById(R.id.message_text);
msg.setText(message.body);
LinearLayout layout = (LinearLayout) vi
.findViewById(R.id.bubble_layout);
LinearLayout parent_layout = (LinearLayout) vi
.findViewById(R.id.bubble_layout_parent);
// if message is mine then align to right
if (message.isMine) {
msg.setBackgroundResource(R.drawable.bubble2);
// layout.setBackgroundResource(R.drawable.bubble2);
parent_layout.setGravity(Gravity.RIGHT);
}
// If not mine then align to left
else {
msg.setBackgroundResource(R.drawable.bubble1);
// layout.setBackgroundResource(R.drawable.bubble1);
parent_layout.setGravity(Gravity.LEFT);
}
msg.setTextColor(Color.BLACK);
return vi;
}
public void add(ChatMessage object) {
chatMessageList.add(object);
}
}
聊天布局的内容是：
<?xml version="1.0" encoding="utf-8"?<android.support.v4.widget.DrawerLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:id="@+id/chat_list_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<android.support.design.widget.AppBarLayout
android:id="@+id/app_bar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="@style/AppTheme.AppBarOverlay">
<android.support.v7.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
app:popupTheme="@style/AppTheme.PopupOverlay" />
</android.support.design.widget.AppBarLayout>
<ListView
android:id="@+id/msgListView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_above="@+id/form"
android:divider="@null"
android:dividerHeight="0dp"
android:paddingBottom="10dp"
android:text="@string/hello_world" />
<include
layout="@layout/type_message_area"
android:layout_width="match_parent"
android:layout_weight="1"
android:layout_height="wrap_content"
android:gravity="bottom" />
</LinearLayout>
<ListView
android:id="@+id/navList"
android:layout_width="200dp"
android:layout_height="match_parent"
android:layout_gravity="left|start"
android:background="#ffeeeeee"/>
聊天气泡的内容是：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/bubble_layout_parent"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="right">
<ImageView
android:id="@+id/imageView2"
android:layout_width="40dp"
android:layout_height="40dp"
android:layout_marginTop="0dp"
android:layout_weight="3"
android:src="@drawable/user_pacific" />
<LinearLayout
android:id="@+id/bubble_layout"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
>
<TextView
android:id="@+id/message_text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:maxEms="12"
android:layout_gravity="center"
android:text="Hi! new message"
android:textColor="@android:color/primary_text_light"
android:background="@drawable/bubble1"/>
</LinearLayout>
所以，我试图通过添加新的聊天气泡来扩展我的基本聊天布局中的ListView。 getCount()返回正确的非零值，但我认为getView()未被调用。另外，我对应该为适配器使用哪些布局感到困惑。上面的代码是混合不同教程的结果，因此它可能没有很好地构建。
我没有收到任何我想从ChatActivity.java填充的消息。
答案 0 :(得分：0)
我之前有过这个问题， 我试着改变代码：
尝试将wrap_content更改为match_parent：
<ListView
android:id="@+id/msgListView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_above="@+id/form"
android:divider="@null"
android:dividerHeight="0dp"
android:paddingBottom="10dp"
android:text="@string/hello_world" />
试试吧〜祝你好运