Android底部導航欄實現（二）之RadioGroup
這裡簡單記錄一下Android底部導航欄通過RadioGroup+Fragment的實現。
這裡寫圖片描述
佈局：
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical"> <include layout="@layout/fragment_content"/> <View android:layout_width="match_parent" android:layout_height="1px" android:background="@color/grey_300" android:elevation="20dp"/> <RadioGroup android:id="@+id/radio_group" android:layout_width="match_parent" android:layout_height="56dp" android:layout_alignParentBottom="true" android:background="@color/white" android:orientation="horizontal"> <RadioButton android:id="@+id/rb_home" style="@style/radiobutton_style" android:checked="true" android:drawableTop="@drawable/radiobutton_bg_home" android:text="@string/item_home" /> <RadioButton android:id="@+id/rb_location" style="@style/radiobutton_style" android:drawableTop="@drawable/radiobutton_bg_location" android:text="@string/item_location"/> <RadioButton android:id="@+id/rb_like" style="@style/radiobutton_style" android:drawableTop="@drawable/radiobutton_bg_like" android:text="@string/item_like"/> <RadioButton android:id="@+id/rb_me" style="@style/radiobutton_style" android:drawableTop="@drawable/radiobutton_bg_me" android:text="@string/item_person"/> </RadioGroup></RelativeLayout>
這裡的drawableTop使用了狀態選擇器
<selector xmlns:android="http://schemas.android.com/apk/res/android"> <item android:drawable="@drawable/home_fill"
android:state_checked="true"/>
<item android:drawable="@drawable/home"/>
</selector>```
####style
<style name="radiobutton_style"> <item name="android:layout_width">0dp</item> <item name="android:padding">3dp</item> <item name="android:layout_height">match_parent</item> <item name="android:layout_weight">1</item> <item name="android:button">@null</item> <item name="android:gravity">center</item> <item name="android:textSize">12sp</item> </style>
###程式碼初始化的程式碼就不記錄了，都是一些findViewById,實現過程無非就是對RadioButton進行監聽一下：
mRadioGroup.setOnCheckedChangeListener(this); @Override public void onCheckedChanged(RadioGroup group, int checkId) { FragmentTransaction transaction = getFragmentManager().beginTransaction(); switch (checkId) { case R.id.rb_home: if (mHomeFragment == null) { mHomeFragment = HomeFragment.newInstance(getString(R.string.item_home)); } transaction.replace(R.id.sub_content, mHomeFragment); break; case R.id.rb_location: if (mLocationFragment == null) { mLocationFragment = LocationFragment.newInstance(getString(R.string.item_location)); } transaction.replace(R.id.sub_content, mLocationFragment); break; case R.id.rb_like: if (mLikeFragment == null) { mLikeFragment = LikeFragment.newInstance(getString(R.string.item_like)); } transaction.replace(R.id.sub_content, mLikeFragment); break; case R.id.rb_me: if (mPersonFragment == null) { mPersonFragment = PersonFragment.newInstance(getString(R.string.item_person)); } transaction.replace(R.id.sub_content, mPersonFragment); break; } setTabState();//設定狀態 transaction.commit(); }
####狀態的設定
private void setTabState() { setHomeState(); setLocationState(); setLikeState(); setMeState(); } /**
- set tab home state */ private void setHomeState() { if (mRadioHome.isChecked()) { mRadioHome.setTextColor(ContextCompat.getColor(getActivity(), R.color.colorPrimary)); } else { mRadioHome.setTextColor(ContextCompat.getColor(getActivity(), R.color.black)); } }
private void setLocationState() { if (mRadioLocation.isChecked()) { mRadioLocation.setTextColor(ContextCompat.getColor(getActivity(), R.color.colorPrimary)); } else { mRadioLocation.setTextColor(ContextCompat.getColor(getActivity(), R.color.black)); } }
private void setLikeState() { if (mRadioLike.isChecked()) { mRadioLike.setTextColor(ContextCompat.getColor(getActivity(), R.color.colorPrimary)); } else { mRadioLike.setTextColor(ContextCompat.getColor(getActivity(), R.color.black)); } }
private void setMeState() { if (mRadioMe.isChecked()) { mRadioMe.setTextColor(ContextCompat.getColor(getActivity(), R.color.colorPrimary)); } else { mRadioMe.setTextColor(ContextCompat.getColor(getActivity(), R.color.black)); } }
這裡需要注意的是， setDefaultFragment();我寫在onCreateVew裡面並沒有生效。這裡我寫在了onStart()方法裡了。
@Override public void onStart() { setDefaultFragment();//寫在onCreateView裡面，當頁面跑到其他Fragment再回來就不會生效 super.onStart(); }
>說明：這幾篇文章沒有過多的文字敘述，因為這些東西也不是很難，而且都是常用的，相信很多人都瞭如指掌了，多說亦是廢話，直接上程式碼看的反而更清楚。
[DownLoad Demo](https://github.com/student9128/BottomNavigationBarForAndroid)