02-Fragment+布局限定符
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2022-06-19 13:10:14
1.初级Fragment
1.初级Fragment
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:text="TextView"/>
</LinearLayout>
<!--右省略-->
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal" android:layout_width="match_parent"
android:layout_height="match_parent">
<!--必须有一个独一无二的id-->
<fragment
android:id="@+id/leftFragment"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:name="com.my.fragmenttest.LeftFragment"/>
<fragment
android:id="@+id/rightFragment"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:name="com.my.fragmenttest.RightFragment"/>
</LinearLayout>
class LeftFragment : Fragment() {
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
return inflater.inflate(R.layout.left_fragment,container,false)
}
}
//右省略
2.动态替换Fragment
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:text="TextView"/>
</LinearLayout>
<!--右省略-->
<!--Another Fragment省略-->
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal" android:layout_width="match_parent"
android:layout_height="match_parent">
<!--必须有一个独一无二的id-->
<fragment
android:id="@+id/leftFragment"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:name="com.my.fragmenttest.LeftFragment"/>
<FrameLayout
android:id="@+id/rightFragment"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"/>
</LinearLayout>
class LeftFragment : Fragment() {
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
return inflater.inflate(R.layout.left_fragment,container,false)
}
}
//右省略
//Another Fragment省略
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
leftFragmentButton.setOnClickListener {
replaceFragment(AnotherFragment())
}
replaceFragment(RightFragment())
}
/**
* 替换Fragment
*/
private fun replaceFragment(fragment : Fragment){
val fragmentManager = supportFragmentManager
val transaction = fragmentManager.beginTransaction()
transaction.replace(R.id.rightFragment,fragment)
transaction.commit()
}
}
3.Fragment返回栈
private fun replaceFragment(fragment : Fragment){
val fragmentManager = supportFragmentManager
val transaction = fragmentManager.beginTransaction()
transaction.replace(R.id.rightFragment,fragment)
//将Fragment加入返回栈,不然通过按钮添加Fragment后,点击返回按钮,程序直接退出
transaction.addToBackStack(null)
transaction.commit()
}
4.Fragment和Activity的交互
//在Activity中获取Fragment
val rightFragment =
supportFragmentManager.findFragmentById(R.id.rightFragment) as RightFragment
//findFragmentById和findViewById相同,可以省略
val f = rightFragment as RightFragment
//Fragment中获取Activity
if (activity != null){
val mainActivity = activity as MainActivity
}
5.Fragment声明周期
class AnotherFragment : Fragment() {
companion object {
const val TAG = "AnotherFragment"
}
/**
* Fragment和Activity建立关系是调用
*/
override fun onAttach(context: Context) {
super.onAttach(context)
Log.e(TAG,"onAttach")
}
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
Log.e(TAG,"onCreate")
}
/**
* 为Fragment创建视图时调用
*/
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
Log.e(TAG,"onCreateView")
return inflater.inflate(R.layout.another_right_framgent,container,false)
}
/**
* Activity被创建时调用
*/
override fun onActivityCreated(savedInstanceState: Bundle?) {
super.onActivityCreated(savedInstanceState)
Log.e(TAG,"onActivityCreated")
}
override fun onStart() {
super.onStart()
Log.e(TAG,"onStart")
}
override fun onResume() {
super.onResume()
Log.e(TAG,"onResume")
}
override fun onPause() {
super.onPause()
Log.e(TAG,"onPause")
}
override fun onStop() {
super.onStop()
Log.e(TAG,"onStop")
}
/**
* 当与Fragment相关联的Activity被移除时调用
*/
override fun onDestroyView() {
super.onDestroyView()
Log.e(TAG,"onDestroyView")
}
override fun onDestroy() {
super.onDestroy()
Log.e(TAG,"onDestroy")
}
/**
* 当Fragment和Activity接触关联时调用
*/
override fun onDetach() {
super.onDetach()
Log.e(TAG,"onDetach")
}
}
6.布局限定符
1:layout_large。
2:layout_sw600dp。
本文地址:https://blog.csdn.net/qq_44637792/article/details/107900738
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