Android 基于环信即时云的IM开发

假如我们想要快速实现一个即时通讯功能，最快捷的方法就是借助网络上的即时云服务。下面我们讲述一下如何利用环信实现一个IM功能。

首先下载环信的SDK，也就是几个库，把demo里面的HXSDKHelper.java，HXSDKModel.java,DefaultHXSDKModel.java，HXPreferenceUtils.java四个文件复制到新建的工程下。稍作修改。

首先在Application中实现初始化SDK

public static DemoHXSDKHelper hxSDKHelper = new DemoHXSDKHelper();

    @Override
    public void onCreate() {
        super.onCreate();
        applicationContext = this;
        instance = this;       
        hxSDKHelper.onInit(applicationContext);
    }

然后在Activity中登陆

        EMChatManager.getInstance().login("123456", "123456", new EMCallBack() {

            @Override
            public void onSuccess() {

                runOnUiThread(new Runnable() {                  
                    @Override
                    public void run() {
                        // TODO Auto-generated method stub
                        Toast.makeText(context, "登陆成功！", Toast.LENGTH_LONG).show();
                    }
                });
            };

            @Override
            public void onProgress(int progress, String status) {
            }

            @Override
            public void onError(final int code, final String message) {

                runOnUiThread(new Runnable() {
                    public void run() {

                        Toast.makeText(getApplicationContext(), "登陆失败" + message, Toast.LENGTH_SHORT).show();
                    }
                });
            }
        });

调用函数进行信息的发送

String string = editText3.getText().toString();
                EMMessage message = EMMessage.createSendMessage(EMMessage.Type.TXT);                                
                String toNum = editText.getText().toString();
                if (toNum.equals("1425193776689")) {
                    message.setChatType(ChatType.GroupChat);
                }

                TextMessageBody txtBody = new TextMessageBody(string);          
                message.addBody(txtBody);               

                message.setReceipt(toNum);              
                try {
                    EMChatManager.getInstance().sendMessage(message);
                } catch (EaseMobException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }                       

在接收信息时，只需要监听广播就可以

// 注册接收消息广播
        receiver = new NewMessageBroadcastReceiver();
        IntentFilter intentFilter = new IntentFilter(EMChatManager.getInstance().getNewMessageBroadcastAction());
        intentFilter.setPriority(5);
        registerReceiver(receiver, intentFilter);

    private class NewMessageBroadcastReceiver extends BroadcastReceiver {
        @Override
        public void onReceive(Context context, Intent intent) {
            // 记得把广播给终结掉
            abortBroadcast();
            String username = intent.getStringExtra("from");
            String msgId    = intent.getStringExtra("msgid");
            // 收到这个广播的时候，message已经在db和内存里了，可以通过id获取mesage对象
            final EMMessage message = EMChatManager.getInstance().getMessage(msgId);
            final TextMessageBody txtBody = (TextMessageBody)message.getBody();
            Toast.makeText(getApplicationContext(), "text message from:" + message.getFrom() + " text:" + txtBody.getMessage() + " \n\r", Toast.LENGTH_LONG).show();
            runOnUiThread(new Runnable() {              
                @Override
                public void run() {             
                    editText2.setText("from:" + message.getFrom() + "\ntext:" + txtBody.getMessage() + " \n");
                }
            });       
        }

    }

这样就可以进行收发。
由于环信的库比较大，编译完之后可执行文件有5M那么大。