在聊天界面实现跳转

实现在聊天界面输入特定的值跳转到新界面

代码：
主布局**

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    >
    <ListView
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:id="@+id/listView"
        android:layout_weight="1"
        android:divider="#0000">

    </ListView>
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <EditText
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:id="@+id/editText"
            android:hint="请在此输入内容"/>
        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="发送"
            android:id="@+id/button_send"/>
    </LinearLayout>

</LinearLayout>

实体类********

public class Chat {
    final static int send=0;
    final static int receive=1;

    String content;
    int type;

    public Chat(String content, int type) {
        this.content = content;
        this.type = type;
    }

    public String getContent() {return content;}
    public int getType() {return type;}
}

子项布局**********

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">
    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/leftLayout"
        android:background="@drawable/qp0218"
        android:layout_margin="10dp"><!--与父布局间距10dp-->
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:id="@+id/leftTextView"/>
    </LinearLayout>
    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/rightLayout"
        android:background="@drawable/qphy"
        android:layout_gravity="right"
        android:layout_margin="10dp">
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/rightTextView"
            android:layout_gravity="center"/>
    </LinearLayout>

</LinearLayout>

适配器**************

public class ChatAdapter extends ArrayAdapter{
    int resource;
    public ChatAdapter(Context context,  int textViewResourceId, List objects) {
        super(context, textViewResourceId, objects);
        resource=textViewResourceId;
    }

    class ViewHolder{
        LinearLayout leftLayout;
        LinearLayout rightLayout;
        TextView leftText;
        TextView rightText;
    }
    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        Chat chat= (Chat) getItem(position);
        View view;ViewHolder viewHolder;
        if (convertView==null){
            view= LayoutInflater.from(getContext()).inflate(resource,null);
            viewHolder=new ViewHolder();
            viewHolder.leftLayout=(LinearLayout)view.findViewById(R.id.leftLayout);
            viewHolder.rightLayout=(LinearLayout)view.findViewById(R.id.rightLayout);
            viewHolder.leftText=(TextView)view.findViewById(R.id.leftTextView);
            viewHolder.rightText=(TextView)view.findViewById(R.id.rightTextView);
            view.setTag(viewHolder);
        }else {
            view=convertView;
            viewHolder= (ViewHolder) view.getTag();

        }
        if (chat.getType()==chat.send){
            viewHolder.leftLayout.setVisibility(View.GONE);
            viewHolder.rightLayout.setVisibility(View.VISIBLE);
            viewHolder.rightText.setText(chat.getContent());
        }
        if (chat.getType()==chat.receive){
            viewHolder.rightLayout.setVisibility(View.GONE);
            viewHolder.leftLayout.setVisibility(View.VISIBLE);
            viewHolder.leftText.setText(chat.getContent());
        }
        return view;
    }
}

主活动******

public class MainActivity extends Activity {
    List<Chat> chatList=new ArrayList<Chat>();
    void initChat(){
        Chat chat1=new Chat("你好！",Chat.send);
        Chat chat2=new Chat("你好！",Chat.receive);
        chatList.add(chat1);
        chatList.add(chat2);
    }
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main_layout);
        initChat();

        final ChatAdapter adapter;
        adapter=new ChatAdapter(MainActivity.this,R.layout.item,chatList);

        final ListView listView=(ListView)findViewById(R.id.listView);
        listView.setAdapter(adapter);

        final EditText editText=(EditText)findViewById(R.id.editText);
        Button button=(Button)findViewById(R.id.button_send);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String string=editText.getText().toString();
                if ("".equals(string)){
                    Chat chat=new Chat("不可以发送空消息哦！",Chat.receive);
                    chatList.add(chat);

                    adapter.notifyDataSetChanged();//更新List

                    listView.setSelection(chatList.size());//跳到最后
                }else if ("1".equals(string)){
                    Chat chat=new Chat(string,Chat.send);
                    chatList.add(chat);
                    editText.setText("");

                    Chat chat1=new Chat("你输入的内容是“"+string+"”，请继续探索。",Chat.receive);
                    chatList.add(chat1);

                    adapter.notifyDataSetChanged();
                    listView.setSelection(chatList.size());
                }else {
                //可以的，当我输入的内容是1时会显示到聊天界面上，
                //但输入其他值则实现跳转，反过来也一样
                    Intent intent=new Intent(MainActivity.this,SecondActivity.class);
                    startActivity(intent);
                }
            }
        });
    }
}