13-7-5 android Tabhost功能实现

开始使用了一个Activity做界面切换，采用visible、gone写法，感觉太麻烦了。

layoutHousehold.setVisibility(View.GONE);layoutCamera.setVisibility(View.GONE);layoutEnvironment.setVisibility(View.GONE);layoutMsg.setVisibility(View.GONE);layoutSetting.setVisibility(View.GONE);layoutLight.setVisibility(View.VISIBLE);

          一般使用MainActivity集成Activity类的时候，通过setContentView(Layout)设计当前的图层，线程称为主线程，当你在定一个类的时候你是不能更改当前的UI的，也就是说一个Activity UI界面对应一个类，不能使用另外的类进行更改，毕竟更新UI需要主线程来完成，新的类不再主线程中（个人观点）。

         那么怎么通过导航栏做Activity切换？使用ViewGroup中的TabHost。

效果：

 1、这里我使用了Tabhost：

 这里导航栏使用setIndicator不是特别灵活，还有就是自己对setIndicator（View）中的view理解的不对，经常出现让我移除图层的错误，所以采用单击监听事件：

protected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main1);tabhost = (TabHost) this.findViewById(android.R.id.tabhost);//获取当前的tabhost,注册tabhost.setup();tabhost.addTab(tabhost.newTabSpec("tab1").setIndicator("tab1").setContent(new Intent(this, light.class))); tabhost.addTab(tabhost.newTabSpec("tab2").setIndicator("tab2").setContent(new Intent(this, Household.class)));tabhost.addTab(tabhost.newTabSpec("tab3").setIndicator("tab3").setContent(new Intent(this, Camera.class)));tabhost.addTab(tabhost.newTabSpec("tab4").setIndicator("tab4").setContent(new Intent(this, Environment.class)));tabhost.addTab(tabhost.newTabSpec("tab5").setIndicator("tab5").setContent(new Intent(this, Msg.class)));tabhost.addTab(tabhost.newTabSpec("tab6").setIndicator("tab6").setContent(new Intent(this, Setting.class)));tabhost.setCurrentTabByTag("tab1");ctrlCmd();}

2、事件监听与图片切换

/*************************************** * 设定面板邮编图标，单击当前图标会变成绿色，同时加载当前按钮对应的activity */public void ctrlCmd(){ctrlLight=(ImageView)this.findViewById(R.id.ctrl_light);ctrlHousehold=(ImageView)this.findViewById(R.id.ctrl_household);ctrlCamera=(ImageView)this.findViewById(R.id.ctrl_camera);ctrlEnvironment=(ImageView)this.findViewById(R.id.ctrl_environment);ctrlMsg=(ImageView)this.findViewById(R.id.ctrl_msg);ctrlSetting=(ImageView)this.findViewById(R.id.ctrl_setting);ctrlonclick ctrl = new ctrlonclick();ctrlLight.setOnClickListener(ctrl);ctrlHousehold.setOnClickListener(ctrl);ctrlCamera.setOnClickListener(ctrl);ctrlEnvironment.setOnClickListener(ctrl);ctrlMsg.setOnClickListener(ctrl);ctrlSetting.setOnClickListener(ctrl);}/************************************************************ * 做一个类用来监听按键的触发程序 * @author hanzhen * */class ctrlonclick implements OnClickListener{@Overridepublic void onClick(View arg0) {// TODO Auto-generated method stubif(arg0 == ctrlLight){Log.i(TAG, "------>>> ctrlLight is pressed");ctrlLight.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_light2));ctrlHousehold.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_household1));ctrlCamera.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_camera1));ctrlEnvironment.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_environment1));ctrlMsg.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_msg1));ctrlSetting.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_set1));tabhost.setCurrentTabByTag("tab1");}else if(arg0 == ctrlHousehold){Log.i(TAG, "------>>> ctrlHousehold is pressed");ctrlLight.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_light1));ctrlHousehold.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_household2));ctrlCamera.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_camera1));ctrlEnvironment.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_environment1));ctrlMsg.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_msg1));ctrlSetting.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_set1));tabhost.setCurrentTabByTag("tab2");}else if(arg0 == ctrlCamera){Log.i(TAG, "------>>> ctrlCamera is pressed");ctrlLight.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_light1));ctrlHousehold.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_household1));ctrlCamera.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_camera2));ctrlEnvironment.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_environment1));ctrlMsg.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_msg1));ctrlSetting.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_set1));tabhost.setCurrentTabByTag("tab3");}else if(arg0 == ctrlEnvironment){Log.i(TAG, "------>>> ctrlEnvironment is pressed");ctrlLight.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_light1));ctrlHousehold.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_household1));ctrlCamera.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_camera1));ctrlEnvironment.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_environment2));ctrlMsg.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_msg1));ctrlSetting.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_set1));tabhost.setCurrentTabByTag("tab4");}else if(arg0 == ctrlMsg){Log.i(TAG, "------>>> ctrlMsg is pressed");ctrlLight.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_light1));ctrlHousehold.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_household1));ctrlCamera.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_camera1));ctrlEnvironment.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_environment1));ctrlMsg.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_msg2));ctrlSetting.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_set1));tabhost.setCurrentTabByTag("tab5");}else if(arg0 == ctrlSetting){Log.i(TAG, "------>>> ctrlSetting is pressed");ctrlLight.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_light1));ctrlHousehold.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_household1));ctrlCamera.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_camera1));ctrlEnvironment.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_environment1));ctrlMsg.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_msg1));ctrlSetting.setImageDrawable(getResources().getDrawable(R.drawable.rbtn_set2));tabhost.setCurrentTabByTag("tab6");}}}

 

遇上的问题：

当我做好xml的布局文件时，我使用

setContentView(R.layout.main1);

出现了错误：

07-05 08:59:02.539: W/dalvikvm(3502): threadid=1: thread exiting with uncaught exception (group=0x40a521f8)07-05 08:59:02.564: E/AndroidRuntime(3502): FATAL EXCEPTION: main07-05 08:59:02.564: E/AndroidRuntime(3502): java.lang.NullPointerException07-05 08:59:02.564: E/AndroidRuntime(3502): at android.widget.TabWidget.dispatchDraw(TabWidget.java:340)07-05 08:59:02.564: E/AndroidRuntime(3502): at android.view.View.draw(View.java:10981)07-05 08:59:02.564: E/AndroidRuntime(3502): at android.view.ViewGroup.drawChild(ViewGroup.java:2887)07-05 08:59:02.564: E/AndroidRuntime(3502): at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)07-05 08:59:02.564: E/AndroidRuntime(3502): at android.view.ViewGroup.drawChild(ViewGroup.java:2885)07-05 08:59:02.564: E/AndroidRuntime(3502): at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)07-05 08:59:02.564: E/AndroidRuntime(3502): at android.view.ViewGroup.drawChild(ViewGroup.java:2885)07-05 08:59:02.564: E/AndroidRuntime(3502): at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)07-05 08:59:02.564: E/AndroidRuntime(3502): at android.view.View.draw(View.java:10981)07-05 08:59:02.564: E/AndroidRuntime(3502): at android.view.ViewGroup.drawChild(ViewGroup.java:2887)07-05 08:59:02.564: E/AndroidRuntime(3502): at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)07-05 08:59:02.564: E/AndroidRuntime(3502): at android.view.ViewGroup.drawChild(ViewGroup.java:2885)07-05 08:59:02.564: E/AndroidRuntime(3502): at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)

主要是在UI中存在TabHost必须要做处理。

super.onCreate(savedInstanceState);setContentView(R.layout.main1);

TabHost tabhost = (TabHost) this.findViewById(android.R.id.tabhost);//获取当前的tabhost,注册tabhost.setup();tabhost.addTab(tabhost.newTabSpec("tab1").setIndicator("tab1").setContent(new Intent(this, light.class)));