简单的仿QQ聊天（自娱自乐聊天室）

设计思路：

首先搭建聊天界面，想要的效果如下

整体为linearlayout线性布局：
1.顶部是聊天界面的名称一个TextView
2.中间是ListView 用来显示聊天信息
3.底部是一个水平布局的linearlayout，包含表情发送按钮输入框EditText

然后搭建聊天信息的布局

此处的布局效果如下

1.整体为水平布局的linearlayout，分为ImageView和右边的linearlayout
2.右边又是一个竖直的linearlayout，分为上面的linearlayout（包括两个TextView）和下面的TextView.

代码实现

两个布局文件

1、聊天界面布局，layout下的chat.xml文件

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="match_parent"android:layout_height="match_parent"android:background="@drawable/chat_background"//整体的背景android:orientation="vertical"><TextViewandroid:layout_width="match_parent"android:layout_height="50dp"android:background="@color/green"android:gravity="center"字体位于中间android:text="自娱自乐聊天室"android:textSize="20sp" /><ListViewandroid:id="@+id/listview"android:layout_width="match_parent"android:layout_height="match_parent"android:layout_weight="1"//自由充满，防止list下面的内容被挤出去android:background="@drawable/chat_background"android:cacheColorHint="#00000000"//设置屏幕滑动的颜色为透明android:divider="@null"></ListView>//设置每条消息之间没有横线隔开<LinearLayoutandroid:layout_width="match_parent"android:layout_height="50dp"android:background="@color/hui"android:gravity="center"><ImageViewandroid:id="@+id/chat_image"android:layout_width="50dp"android:layout_height="wrap_content"android:layout_margin="5dp"android:src="@mipmap/addsimle" />//添加表情的按钮图标<Buttonandroid:id="@+id/button_back"android:layout_width="50dp"android:layout_height="match_parent"android:layout_margin="5dp"android:background="@drawable/btn_background"android:text="回复" /><EditTextandroid:id="@+id/chat_edittext"android:layout_width="0dp"android:layout_height="match_parent"android:layout_weight="1"android:background="@drawable/denglu"android:hint="输入内容" /><Buttonandroid:id="@+id/button_send"android:layout_width="50dp"android:layout_height="match_parent"android:layout_margin="5dp"android:background="@drawable/btn_background"android:text="发送" /></LinearLayout>
</LinearLayout>
————————————————————————————————————————————————————
//这里面android:background="@drawable/chat_background"整体背景的设置使用渐变色 在@drawable/chat_background下的代码如下：
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"><gradient//由上到下颜色渐变android:startColor="#ace7ef"android:centerColor="#c5e1dd"android:endColor="#e7d9c5"android:type="linear" //线性渐变 此外还有radial圆形渐变，sweep扇形渐变android:angle="-90"/>
</shape>

完成后布局如下：

2、消息布局，layout下的message.xml文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"android:orientation="vertical"android:layout_width="match_parent"android:layout_height="match_parent">
<TextViewandroid:id="@+id/message_time"android:layout_width="match_parent"android:layout_height="wrap_content"android:text="星期几 时间"//在每条消息上方显示该消息发送的日期和时间android:gravity="center"android:padding="10dp"/><LinearLayoutandroid:layout_width="match_parent"android:layout_height="wrap_content"><ImageView//头像，插入图片 设置大小android:id="@+id/message_img"android:layout_width="60dp"android:layout_height="60dp"android:src="@mipmap/t1"/><LinearLayout//竖直分布的LinearLayoutandroid:layout_width="match_parent"android:layout_height="wrap_content"android:orientation="vertical"android:layout_marginLeft="5dp"><LinearLayout//水平布局的LinearLayoutandroid:layout_width="match_parent"android:layout_height="wrap_content"android:orientation="horizontal"><TextViewandroid:id="@+id/textview_title"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="管理员"android:padding="5dp"android:textColor="@color/red"android:background="@drawable/message_title"//设置头衔的背景颜色android:textSize="15dp"/><TextViewandroid:id="@+id/textview_name"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="昵称"android:textColor="@color/black"android:textSize="15dp"android:layout_marginLeft="5dp"/></LinearLayout><TextViewandroid:id="@+id/textview_message"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="我是一只小萌兔"android:textColor="@color/black"android:background="@mipmap/chat"//添加聊天框效果 ，这里用到了.9图android:layout_marginRight="60dp"/></LinearLayout></LinearLayout>
</LinearLayout>

布局完成后效果如下：

关于发送表情

1、首先在chat.xml文件中添加一个Gridview

    <GridViewandroid:id="@+id/gridview"android:layout_width="match_parent"android:layout_height="200dp"android:numColumns="3"//设置为3列android:visibility="gone"></GridView>//设置没有添加时为空

2、然后写一个layout布局表情

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"android:orientation="vertical"android:layout_width="match_parent"android:layout_height="match_parent"android:gravity="center">
<ImageViewandroid:id="@+id/imageview"android:layout_width="60dp"android:layout_height="60dp"android:src="@mipmap/biaoqing1"android:padding="10dp"/>
</LinearLayout>

3、写一个smileadapt与数据建立桥梁

public class SmileAdapter extends BaseAdapter {private int [] mDate={R.mipmap.biaoqing1,R.mipmap.biaoqing2,R.mipmap.biaoqing3,R.mipmap.b4,R.mipmap.b5, R.mipmap.b6,};//定义表情数组private LayoutInflater mFlater;public SmileAdapter(LayoutInflater mFlater) {this.mFlater = mFlater;}@Overridepublic int getCount() {return mDate.length;}@Overridepublic Object getItem(int position) {return position;}@Overridepublic long getItemId(int position) {return position;}@Overridepublic View getView(int position, View convertView, ViewGroup parent) {ViewHolder vh = null;if(convertView==null){convertView = mFlater.inflate(R.layout.item_image,null);vh = new ViewHolder();vh.imageview = (ImageView) convertView.findViewById(R.id.imageview);convertView.setTag(vh);}vh = (ViewHolder) convertView.getTag();vh.imageview.setImageResource(mDate[position]);return convertView;}class  ViewHolder{ImageView imageview;}
}

在ChatActivity中：

  //声明表情变量 并找到，添加点击事件private ImageView mImageView;private Html.ImageGetter mImageGetter;private GridView mGridView;private SmileAdapter mSmileAdapter;private String[] mImageName = {"biaoqing1", "biaoqing2", "biaoqing3","b4","b5","b6"};@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.chat);mImageView = (ImageView) findViewById(R.id.chat_image);mImageView.setOnClickListener(this);mImageGetter = new Html.ImageGetter() {@Overridepublic Drawable getDrawable(String source) {Drawable drawable = null;if (source != null) {Class clazz = R.mipmap.class;try {Field field = clazz.getDeclaredField(source);//用到了反射int sourceId = field.getInt(clazz);drawable = getResources().getDrawable(sourceId);drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());} catch (NoSuchFieldException e) {e.printStackTrace();} catch (IllegalAccessException e) {e.printStackTrace();}} else {drawable = getResources().getDrawable(R.mipmap.ic_launcher);drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());}return drawable;}};mData = new ArrayList<>();mAdapter = new MessageAdapter(getLayoutInflater(), mData, mImageGetter);mListView.setAdapter(mAdapter);mSmileAdapter = new SmileAdapter(getLayoutInflater());mGridView.setAdapter(mSmileAdapter);
//点击某个表情时，添加到输入框mGridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {@Overridepublic void onItemClick(AdapterView<?> parent, View view, int position, long id) {Log.d("TAG","DFSDFSD");Spanned spanned = Html.fromHtml("<img src=''/>", mImageGetter, null);//富文本，利用Spanned得到图片mEditText.getText().insert(mEditText.getSelectionStart(), spanned);//将spanned添加到mEditText中}});
——————————————————————————————
//点击事件如下@Overridepublic void onClick(View v) {switch (v.getId()) {case R.id.chat_image:if (mGridView.getVisibility() == View.VISIBLE) {mGridView.setVisibility(View.GONE);} else {mGridView.setVisibility(View.VISIBLE);}break;

每点击一次时会在输入框中出现一个表情

关于发送消息（重点难点）

1、首先新建一个Message类，包含消息布局中的属性，然后给出setter和getter，及构造器

public class ChatMessage {private long time;//时间private int imgId;//头像图片private String message_title;//头衔private String message_name;//昵称private String message;//聊天内容public ChatMessage(String message_title, long time, String message_name, String message, int imgId) {this.message_title = message_title;this.time = time;this.message_name = message_name;this.message = message;this.imgId = imgId;}public ChatMessage() {}public String getMessage_title() {return message_title;}public void setMessage_title(String message_title) {this.message_title = message_title;}public long getTime() {return time;}public void setTime(long time) {this.time = time;}public String getMessage_name() {return message_name;}public void setMessage_name(String message_name) {this.message_name = message_name;}public String getMessage() {return message;}public void setMessage(String message_title) {this.message = message_title;}public int getImgId() {return imgId;}public void setImgId(int imgId) {this.imgId = imgId;}
}

2、新建MessageAdapter,重写四个方法，与message.xml布局的信息获得联系
Adapter的作用就是ListView界面与数据之间的桥梁，当列表里的每一项显示到页面时，都会调用Adapter的getView方法返回一个View。

    //**Inflater英文意思是膨胀，在Android中应该是扩展的意思吧。 LayoutInflater的作用类似于 findViewById(),不同点是LayoutInflater是用来找layout文件夹下的xml布局文件，并且实例化！而 findViewById()是找具体某一个xml下的具体 widget控件(如:Button,TextView等)。**public class MessageAdapter extends BaseAdapter {private LayoutInflater mFlater;private List<ChatMessage> mData;private Html.ImageGetter mImageGetter;private SimpleDateFormat mFormat;public static  final  int MESSAG_SEND=0;public static  final  int MESSAGE_BACK=1;public static  final  int TYPE=2;//构造器public MessageAdapter(LayoutInflater mFlater, List<ChatMessage> mData, Html.ImageGetter mImageGetter) {this.mFlater = mFlater;this.mImageGetter = mImageGetter;this.mData = mData;mFormat = new SimpleDateFormat("EEE HH:mm");//日期和时间}@Overridepublic int getViewTypeCount() {return TYPE;//类型。message的类型 分为发送MESSAG_SEND和回复MESSAGE_BACK，所以返回2}@Overridepublic int getItemViewType(int position) {return mData.get(position).getType();}//返回当前view的布局显示的类型@Overridepublic int getCount() {return mData.size();}@Overridepublic Object getItem(int position) {return position;}@Overridepublic long getItemId(int position) {return position;}@Overridepublic View getView(int position, View convertView, ViewGroup parent) {// 分为发送信息和回复信息，分别适配两个布局中的数据ViewHolder vh = null;ViewHolderBack vhBack=null;int type = getItemViewType(position);if (convertView == null) {switch (type) {case MESSAG_SEND:convertView = mFlater.inflate(R.layout.message, null);vh = new ViewHolder();vh.textView_time = (TextView) convertView.findViewById(R.id.message_time);vh.imageView_head = (ImageView) convertView.findViewById(R.id.message_img);vh.textView_title = (TextView) convertView.findViewById(R.id.textview_title);vh.textView_name = (TextView) convertView.findViewById(R.id.textview_name);vh.textView_message = (TextView) convertView.findViewById(R.id.textview_message);convertView.setTag(vh);break;case MESSAGE_BACK:convertView = mFlater.inflate(R.layout.backmessage, null);vhBack = new ViewHolderBack();vhBack.textView_time = (TextView) convertView.findViewById(R.id.message_time);vhBack.imageView_head = (ImageView) convertView.findViewById(R.id.message_img);vhBack.textView_title = (TextView) convertView.findViewById(R.id.textview_title);vhBack.textView_name = (TextView) convertView.findViewById(R.id.textview_name);vhBack.textView_message = (TextView) convertView.findViewById(R.id.textview_message);convertView.setTag(vhBack);break;default:break;}}ChatMessage msg = mData.get(position);switch (type){case MESSAG_SEND:vh = (ViewHolder) convertView.getTag();Spanned spanned = Html.fromHtml(msg.getMessage(), mImageGetter, null);vh.imageView_head.setImageResource(msg.getImgId());vh.textView_time.setText(mFormat.format(new Date(msg.getTime())));vh.textView_title.setText(msg.getMessage_title());vh.textView_name.setText(msg.getMessage_name());vh.textView_message.setText(spanned);break;case MESSAGE_BACK:vhBack = (ViewHolderBack) convertView.getTag();Spanned spanned2 = Html.fromHtml(msg.getMessage(), mImageGetter, null);vhBack.imageView_head.setImageResource(msg.getImgId());//得到图片vhBack.textView_time.setText(mFormat.format(new Date(msg.getTime())));vhBack.textView_title.setText(msg.getMessage_title());vhBack.textView_name.setText(msg.getMessage_name());vhBack.textView_message.setText(spanned2);break;default:break;}return convertView;}class ViewHolder {TextView textView_time;ImageView imageView_head;TextView textView_title;TextView textView_name;TextView textView_message;}class ViewHolderBack{TextView textView_time;ImageView imageView_head;TextView textView_title;TextView textView_name;TextView textView_message;}
}

3、ChatActivity

public class ChatActivity extends Activity implements View.OnClickListener {private Button mButtonSend;private Button mButtonBack;private ImageView mImageView;private EditText mEditText;private Html.ImageGetter mImageGetter;private List<ChatMessage> mData;private MessageAdapter mAdapter;private ListView mListView;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.chat);//找到相应的数据mButtonSend = (Button) findViewById(R.id.button_send);mButtonBack = (Button) findViewById(R.id.button_back);mListView = (ListView) findViewById(R.id.listview);mEditText = (EditText) findViewById(R.id.chat_edittext);mImageView = (ImageView) findViewById(R.id.chat_image);//设置点击事件mButtonSend.setOnClickListener(ChatActivity.this);mButtonBack.setOnClickListener(ChatActivity.this);mImageView.setOnClickListener(this);mImageGetter = new Html.ImageGetter() {@Overridepublic Drawable getDrawable(String source) {Drawable drawable = getResources().getDrawable(R.mipmap.biaoqing2);drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());return drawable;}};mData = new ArrayList<>();mAdapter = new MessageAdapter(getLayoutInflater(), mData, mImageGetter);//与数据连接mListView.setAdapter(mAdapter);}
//下面是点击事件方法@Overridepublic void onClick(View v) {switch (v.getId()) {case R.id.chat_image://点击表情是添加表情if (mGridView.getVisibility() == View.VISIBLE) {mGridView.setVisibility(View.GONE);} else {mGridView.setVisibility(View.VISIBLE);}break;case R.id.button_send://发送按钮//下面给message中的属性赋值ChatMessage message = new ChatMessage();message.setImgId(R.mipmap.t2);message.setMessage_title("盟主");message.setMessage_name("小萌兔");message.setType(MessageAdapter.MESSAG_SEND);//信息类型是发送message.setTime(System.currentTimeMillis());//显示时间message.setMessage(filterHtml(Html.toHtml(mEditText.getText())));//filterHtml方法用于出去消息框中多余的部分mData.add(message);mAdapter.notifyDataSetChanged();//刷新mListView.setSelection(mData.size() - 1);//设置自动下滚mEditText.setText("");//清空输入框break;//回复按钮case R.id.button_back:ChatMessage messageBack = new ChatMessage();messageBack.setImgId(R.mipmap.t1);messageBack.setMessage_title("圣子");messageBack.setMessage_name("潇洒哥");messageBack.setType(MessageAdapter.MESSAGE_BACK);messageBack.setTime(System.currentTimeMillis());messageBack.setMessage(filterHtml(Html.toHtml(mEditText.getText())));mData.add(messageBack);mAdapter.notifyDataSetChanged();mListView.setSelection(mData.size() - 1);mEditText.setText("");break;default:break;}}}
//filterHtml方法用于出去消息框中多余的部分private String filterHtml(String str) {str = str.replaceAll("<(?!br|img)[^>]+>","").trim();return str;}

补充

在这个过程中需要注意一些没有提到的细节
1、设置全屏: 再次用到的方法是在androidManifest.xml文件中，activity中添加

    <activityandroid:name=".ChatActivity"android:theme="@android:style/Theme.NoTitleBar" />//设置为全屏
/>

2.注意去掉每条list之间的黑线
3.关于按钮的点击效果,在drawable下：

//btn_normal
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"><corners android:radius="@dimen/bnt_corners" /><solid android:color="@color/blue" />
</shape>
——————————————————————————————————————————————————————
//btn_pressed
<shape xmlns:android="http://schemas.android.com/apk/res/android"><corners android:radius="@dimen/bnt_corners" /><solid android:color="#ddcccc" />
</shape>
//btn_background
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android"><item android:drawable="@drawable/btn_pressed" android:state_pressed="true" /><item android:drawable="@drawable/" />
</selector>
//头衔背景的drawable
<shape xmlns:android="http://schemas.android.com/apk/res/android">
<solid android:color="@color/green"></solid>//颜色<corners android:radius="20dp"></corners>//角的圆滑程度
</shape>

4、在布局回复信息时

<LinearLayoutandroid:layout_width="wrap_content"//不要写成match_parentandroid:layout_height="wrap_content"android:layout_weight="1"//自由充满android:orientation="vertical"android:gravity="right">

5、这里我还写了一个登陆界面，后面将加入数据库来完善。现在只是简单的两个activity之间的跳转，在MainActivity中

   @Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);mButtonLogin = (Button) findViewById(R.id.button_login);mButtonLogin.setOnClickListener(new View.OnClickListener() {//设置点击事件@Overridepublic void onClick(View v) {Intent intent = new Intent(MainActivity.this,ChatActivity.class);//定义一个Intent，指向下一个界面startActivity(intent);//直接启动intent}});}

最终效果如下
：