重要方法
clear():清除此Bundle映射中的所有保存的数据。
clone():克隆当前Bundle
containsKey(String key):返回指定key的值
getString(String key):返回指定key的字符
hasFileDescriptors():指示是否包含任何捆绑打包文件描述符
isEmpty():如果这个捆绑映射为空,则返回true
putString(String key, String value):插入一个给定key的字符串值
readFromParcel(Parcel parcel):读取这个parcel的内容
remove(String key):移除指定key的值
writeToParcel(Parcel parcel, int flags):写入这个parcel的内容
Intent消息传递
1、直接调用putExtra()方法将信息添加到Extra属性中,然后通过调用getXXXExtra()方法进行获取即可。这种方式比较简单、直接,主要用于数据量比较少的情况下。
例如:
Activity1中存数据:
Intent intent = new Intent(Activity1.this, Activity2.class);intent.putExtra("name","jack");startActivity(intent);
Activity2中去数据:
Intent myintent=this.getIntent();String Name=myintent.getStringExtra("name");
2、先将数据封装到Bundle包中,Bundle可以看成是一个“键/值”映射的哈希表。当数据量比较多时,可以使用Bundle存放数据;然后通过putExtras()方法将Bundle对象添加到Extra属性中,再通过使用getExtras()方法获取存放的Bundle对象,最后读取Bundle包中的数据。这种方式是简介通过Bundle包对数据先进行封装,再进行传递,实现起来比较繁琐,因此,主要用于数据量较多的情况。
例如:
Activity1中:
Intent myintent=new Intent();myintent.setClass(Activity1.this,Activity2.class);Bundle mybundle=new Bundle();mybundle.putString("name","jace");mybundle.putInt("age",40);myintent.putExtras(mybundle);Activity1.this.startActivity(myintent);
Activity2中:
Intent myintent=this.getIntent();bundle mybundle=myintent.getExtras();String Name=mybundle.getString("name");Int Age=mybundle.getInt("age");
Bundle在Handler中的数据传输
发送消息:
//发送一个消息到Handler发送一个BluetoothChat.MESSAGE_STATE_CHANGE消息到UI线程中//对应BluetoothChat的mHandlermHandler.obtainMessage(BluetoothChat.MESSAGE_STATE_CHANGE, state, -1).sendToTarget();
或
//发送链接的设备名称到UI Activity界面Message msg = mHandler.obtainMessage(BluetoothChat.MESSAGE_DEVICE_NAME);Bundle bundle = new Bundle();bundle.putString(BluetoothChat.DEVICE_NAME, device.getName());msg.setData(bundle);mHandler.sendMessage(msg);
或
Message msg = myHandler.obtainMessage();//将msg发送到目标对象,所谓的目标对象,就是生成该msg对象的handler对象Bundle b = new Bundle();b.putInt("age", 20);b.putString("name", "Jhon");msg.setData(b);msg.sendToTarget();
获取消息
private final Handler mHandler = new Handler() {@Overridepublic void handleMessage(Message msg) {switch (msg.what) {case MESSAGE_STATE_CHANGE:if(D) Log.i(TAG, "MESSAGE_STATE_CHANGE: " + msg.arg1);switch (msg.arg1) {case BluetoothChatService.STATE_CONNECTED:mTitle.setText(R.string.title_connected_to);//设置状态为已经连接mTitle.append(mConnectedDeviceName);//添加设备名称 标题为链接的设备名称mConversationArrayAdapter.clear();//清理聊天记录break;case BluetoothChatService.STATE_CONNECTING:mTitle.setText(R.string.title_connecting);break;case BluetoothChatService.STATE_LISTEN:case BluetoothChatService.STATE_NONE:mTitle.setText(R.string.title_not_connected);break;}break;case MESSAGE_WRITE:byte[] writeBuf = (byte[]) msg.obj;// construct a string from the buffer//将自己写入的消息也显示到会话列表中String writeMessage = new String(writeBuf);mConversationArrayAdapter.add("Me: " + writeMessage);break;case MESSAGE_READ:byte[] readBuf = (byte[]) msg.obj;// construct a string from the valid bytes in the buffer//取得内容并添加到聊天对话列表中String readMessage = new String(readBuf, 0, msg.arg1);mConversationArrayAdapter.add(mConnectedDeviceName+": " + readMessage);break;case MESSAGE_DEVICE_NAME:// save the connected device's name//保存链接的设备名称,并显示一个toast提示mConnectedDeviceName = msg.getData().getString(DEVICE_NAME);Toast.makeText(getApplicationContext(), "Connected to "+ mConnectedDeviceName, Toast.LENGTH_SHORT).show();break;case MESSAGE_TOAST://处理链接(发送)失败的消息Toast.makeText(getApplicationContext(), msg.getData().getString(TOAST),Toast.LENGTH_SHORT).show();break;}}};
或
public void handleMessage(Message msg) {Bundle b = msg.getData();int age = b.getInt("age");String name = b.getString("name");System.out.println("age is " + age + ", name is" + name);System.out.println("Handler--->" + Thread.currentThread().getId());System.out.println("handlerMessage");}