片段事务中的实例化错误
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【中文标题】片段事务中的实例化错误【英文标题】：Instantiate Error in Fragment Transaction 【发布时间】：2021-11-23 17:12:23 【问题描述】：我在 Fragment Transaction 中遇到问题。 我想更改单击按钮时显示的片段 但是当我尝试单击它时，应用程序会关闭。
它一直显示错误消息， 二进制 XML 文件第 6 行：错误膨胀，以及 无法实例化片段确保类名存在，是公共的，并且有一个公共的空构造函数
我尝试添加 newInstace() 代码，但仍然无法正常工作
下面是错误代码和我的活动，片段代码。我不知道出了什么问题... 请帮帮我。
E/androidRuntime: FATAL EXCEPTION: main
Process: com.example.illo, PID: 10709
android.view.InflateException: Binary XML file line #6: Binary XML file line #6: Error inflating class fragment
Caused by: android.view.InflateException: Binary XML file line #6: Error inflating class fragment
Caused by: android.app.Fragment$InstantiationException: Unable to instantiate fragment com.example.illo.WritePost1_Fragment: make sure class name exists, is public, and has an empty constructor that is public
at android.app.Fragment.instantiate(Fragment.java:538)
at android.app.FragmentContainer.instantiate(FragmentContainer.java:53)
at android.app.FragmentManagerImpl.onCreateView(FragmentManager.java:3547)
at android.app.FragmentController.onCreateView(FragmentController.java:102)
at android.app.Activity.onCreateView(Activity.java:6323)
at androidx.fragment.app.FragmentActivity.onCreateView(FragmentActivity.java:300)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:780)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:730)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:863)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:824)
at android.view.LayoutInflater.inflate(LayoutInflater.java:515)
at android.view.LayoutInflater.inflate(LayoutInflater.java:423)
at com.example.illo.WritePost_Step2_Fragment.onCreateView(WritePost_Step2_Fragment.kt:27)
at androidx.fragment.app.Fragment.performCreateView(Fragment.java:2963)
at androidx.fragment.app.FragmentStateManager.createView(FragmentStateManager.java:518)
at androidx.fragment.app.FragmentStateManager.moveToExpectedState(FragmentStateManager.java:282)
at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:2189)
at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute(FragmentManager.java:2100)
at androidx.fragment.app.FragmentManager.execPendingActions(FragmentManager.java:2002)
at androidx.fragment.app.FragmentManager$5.run(FragmentManager.java:524)
at android.os.Handler.handleCallback(Handler.java:873)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:6669)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
Caused by: java.lang.ClassNotFoundException: Didn't find class "com.example.illo.WritePost1_Fragment" on path: DexPathList[[zip file "/data/app/com.example.illo-8XrFiUkhowzrFMYYQ7X5qw==/base.apk"],nativeLibraryDirectories=[/data/app/com.example.illo-8XrFiUkhowzrFMYYQ7X5qw==/lib/x86, /system/lib]]
at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:134)
at java.lang.ClassLoader.loadClass(ClassLoader.java:379)
at java.lang.ClassLoader.loadClass(ClassLoader.java:312)
at android.app.Fragment.instantiate(Fragment.java:524)
at android.app.FragmentContainer.instantiate(FragmentContainer.java:53)
at android.app.FragmentManagerImpl.onCreateView(FragmentManager.java:3547)
at android.app.FragmentController.onCreateView(FragmentController.java:102)
at android.app.Activity.onCreateView(Activity.java:6323)
at androidx.fragment.app.FragmentActivity.onCreateView(FragmentActivity.java:300)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:780)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:730)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:863)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:824)
at android.view.LayoutInflater.inflate(LayoutInflater.java:515)
at android.view.LayoutInflater.inflate(LayoutInflater.java:423)
at com.example.illo.WritePost_Step2_Fragment.onCreateView(WritePost_Step2_Fragment.kt:27)
at androidx.fragment.app.Fragment.performCreateView(Fragment.java:2963)
at androidx.fragment.app.FragmentStateManager.createView(FragmentStateManager.java:518)
at androidx.fragment.app.FragmentStateManager.moveToExpectedState(FragmentStateManager.java:282)
at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:2189)
at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute(FragmentManager.java:2100)
at androidx.fragment.app.FragmentManager.execPendingActions(FragmentManager.java:2002)
at androidx.fragment.app.FragmentManager$5.run(FragmentManager.java:524)
at android.os.Handler.handleCallback(Handler.java:873)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:6669)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
class WritePostActivity : AppCompatActivity()
// step 프래그먼트 가져오기
lateinit var step1Fragment : WritePost_Step1_Fragment
lateinit var step2Fragment : WritePost_Step2_Fragment
override fun onCreate(savedInstanceState: Bundle?)
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_write_post)
// 툴바 설정
toolbarSetting()
// 처음에는 step1로 설정
ShowStep1()
// step 이동 버튼
btn_step1.setOnClickListener
ShowStep1()
Toast.makeText(this@WritePostActivity, "Write Post Step1", Toast.LENGTH_SHORT).show()
btn_step2.setOnClickListener
ShowStep2()
Toast.makeText(this@WritePostActivity, "Write Post Step2", Toast.LENGTH_SHORT).show()
// 글 쓰기 완료 버튼! (누르면 게시글이 등록됨)
btn_write_post_ok.setOnClickListener
// *----서버/DB 필요----*
// 포스트로 등록
// 툴바 세팅
fun toolbarSetting()
// 툴바로 세팅
setSupportActionBar(toolbar_write_post)
supportActionBar?.setDisplayShowCustomEnabled(true)
supportActionBar?.setDisplayShowTitleEnabled(false)
supportActionBar?.setHomeAsUpIndicator(R.drawable.icon_to_left); // 뒤로 가기 버튼 커스텀
supportActionBar?.setDisplayHomeAsUpEnabled(true) // 뒤로 가기 버튼 자동 생성
// 뒤로가기 버튼 설정
toolbar_write_post.setNavigationOnClickListener
finish() // 액티비티 끝내기
overridePendingTransition(R.anim.no_animation, R.anim.slide_out_left) // 애니메이션
fun ShowStep1()
step1Fragment = WritePost_Step1_Fragment()
supportFragmentManager.beginTransaction()
.replace(R.id.fragment_write_post, step1Fragment)
.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN)
.commit()
fun ShowStep2()
step2Fragment = WritePost_Step2_Fragment()
supportFragmentManager.beginTransaction()
.replace(R.id.fragment_write_post, step2Fragment)
.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN)
.commit()
class WritePost_Step2_Fragment : Fragment()
companion object
fun newInstance(foo: Int): WritePost_Step2_Fragment
val args= Bundle()
args.putInt("foo", foo)
val fragment= WritePost_Step2_Fragment()
fragment.arguments= args
return fragment
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View?
val view: View = inflater.inflate(R.layout.fragment_write_post_step2, container, false)
return view
// Activity의 OnCreate와 같은 역할을 하는 함수
override fun onViewCreated(view: View, savedInstanceState: Bundle?)
Log.d("life_cycle", "F onViewCreated")
super.onViewCreated(view, savedInstanceState)
【问题讨论】：
fragment_write_post_step2 是有效的 xml 文件吗？ 【参考方案1】：你的 xml 文件有错误（特别是第 6 行），首先检查你的 xml 文件，它位于 res/layout 目录中
【讨论】：
我是个傻瓜............谢谢以上是关于片段事务中的实例化错误的主要内容，如果未能解决你的问题，请参考以下文章