我正在为Android编写聊天客户端,但是我在客户端中放置对话框方面遇到了一些问题。我的聊天屏幕由一个带有文本框和发送按钮的ListView
组成。对于发出去的消息,文本在ListView
行中左对齐。对于接收到的消息,文本在ListView
行中右对齐。然而,聊天气泡不会根据接收到的消息文本长度进行调整大小。对于左对齐的发出去的消息,不会出现这个问题。
以下是屏幕截图。
聊天消息文本存储在数据库中,并通过游标适配器在ListView
中显示。聊天文本的对齐方式在MessageAdapter
的Java源代码中实时确定。两个聊天气泡都使用了Android的九宫格图像。
以下是我的聊天活动布局,存在问题的ListView
是messageHistoryList
:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:padding="10dip"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<ListView
android:id="@+id/messageHistoryList"
android:layout_width="wrap_content"
android:layout_height="0px"
android:layout_weight="1"/>
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content" >
<EditText
android:id="@+id/message"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:gravity="top"
android:layout_weight="1"/>
<Button
android:id="@+id/sendMessageButton"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="4"
android:text="Send"/>
</LinearLayout>
</LinearLayout>
列表视图行布局:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<RelativeLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/userAndMessage">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/textUser"
android:textStyle="bold"
android:textColor="@color/blue"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/textMessage"
android:textColor="@color/blue"
android:textStyle="bold"/>
</RelativeLayout>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/textTime"
android:textColor="@color/blue"/>
</RelativeLayout>
消息适配器:
public class MessageAdapter extends SimpleCursorAdapter {
static final String[] FROM = { ChatHistoryManager.C_TIME };
static final int[] TO = { R.id.textTime };
static final int MESSAGE_INCOMING_DIR = 1;
private String incomingMessageUserName;
private String selfUserName;
public MessageAdapter(Context context, Cursor cursor) {
super(context, R.layout.message_list_item, cursor, FROM, TO);
}
@Override
public void bindView(View row, Context context, Cursor cursor) {
super.bindView(row, context, cursor);
int messageDir = cursor.getInt(cursor.getColumnIndex(ChatHistoryManager.C_DIR));
if(messageDir == MESSAGE_INCOMING_DIR) {
RelativeLayout.LayoutParams userNameAndChatMessageParams = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
userNameAndChatMessageParams.addRule(RelativeLayout.ALIGN_PARENT_RIGHT, RelativeLayout.TRUE);
RelativeLayout.LayoutParams userNameParams = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
userNameParams.addRule(RelativeLayout.LEFT_OF, R.id.textMessage);
RelativeLayout.LayoutParams chatMessageParams = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
chatMessageParams.addRule(RelativeLayout.ALIGN_PARENT_RIGHT, R.id.textUser);
RelativeLayout.LayoutParams timeParams = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
timeParams.addRule(RelativeLayout.ALIGN_RIGHT, R.id.userAndMessage);
timeParams.addRule(RelativeLayout.BELOW, R.id.userAndMessage);
row.setBackgroundResource(R.color.grey);
// Set the chat message
String chatMessage = cursor.getString(cursor.getColumnIndex(ChatHistoryManager.C_TEXT));
TextView textMessage = (TextView) row.findViewById(R.id.textMessage);
textMessage.setText(chatMessage.trim());
textMessage.setLayoutParams(chatMessageParams);
// Format the time stamp of the message
long timestamp = cursor.getLong(cursor.getColumnIndex(ChatHistoryManager.C_TIME));
TextView textTime = (TextView) row.findViewById(R.id.textTime);
String readableTimeStamp = (String) DateUtils.getRelativeTimeSpanString(timestamp);
textTime.setText(readableTimeStamp.trim());
textTime.setLayoutParams(timeParams);
// Format the message owner and the message
TextView textUser = (TextView) row.findViewById(R.id.textUser);
textUser.setText(incomingMessageUserName + ": ");
textUser.setLayoutParams(userNameParams);
row.setBackgroundResource(R.drawable.incoming_chat_bubble);
}
else {
RelativeLayout.LayoutParams userNameAndChatMessageParams = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
userNameAndChatMessageParams.addRule(RelativeLayout.RIGHT_OF, R.id.userImage);
RelativeLayout.LayoutParams userImageParams = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
userImageParams.addRule(RelativeLayout.ALIGN_PARENT_LEFT, RelativeLayout.TRUE);
RelativeLayout.LayoutParams userNameParams = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
userNameParams.addRule(RelativeLayout.ALIGN_LEFT, R.id.userAndMessage);
RelativeLayout.LayoutParams chatMessageParams = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
chatMessageParams.addRule(RelativeLayout.RIGHT_OF, R.id.textUser);
RelativeLayout.LayoutParams timeParams = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
timeParams.addRule(RelativeLayout.ALIGN_LEFT, R.id.userAndMessage);
timeParams.addRule(RelativeLayout.BELOW, R.id.userAndMessage);
// Set the chat message
String chatMessage = cursor.getString(cursor.getColumnIndex(ChatHistoryManager.C_TEXT));
TextView textMessage = (TextView) row.findViewById(R.id.textMessage);
textMessage.setText(chatMessage);
textMessage.setLayoutParams(chatMessageParams);
// Format the time stamp of the message
long timestamp = cursor.getLong(cursor.getColumnIndex(ChatHistoryManager.C_TIME));
TextView textTime = (TextView) row.findViewById(R.id.textTime);
textTime.setText(DateUtils.getRelativeTimeSpanString(timestamp));
textTime.setLayoutParams(timeParams);
// Format the message owner and the message
TextView textUser = (TextView) row.findViewById(R.id.textUser);
textUser.setText(selfUserName + ": ");
textUser.setLayoutParams(userNameParams);
row.setBackgroundResource(R.drawable.outgoing_chat_bubble);
}
}
public void setIncomingMessageUserName(String inputUserName) {
this.incomingMessageUserName = inputUserName;
}
public void setSelfUserName(String inputUserName) {
this.selfUserName = inputUserName;
}
}