当我的 Activity 中有零代码时微调器泄漏
Spinner is leaking when I have ZERO code inside my Activity
我的 MainActivity 中的代码为零，只有我创建的 XML 布局和 Spinner 正在泄漏，不确定为什么会发生这种情况或如何解决此问题。有谁知道为什么？我正在使用 LeakCanary 库
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
}
我的 XML 布局 activity_main：
在我的 mainactivity.java
中没有添加任何其他内容
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="MainActivity">
<androidx.appcompat.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="@color/colorPrimary"
android:elevation="4dp"
app:contentInsetStart="0dp"
app:layout_collapseMode="pin"
app:layout_constraintTop_toTopOf="parent">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:id="@+id/toolbar_icon"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:background="?attr/actionBarItemBackground"
android:paddingStart="12dp"
android:paddingEnd="3dp"
app:srcCompat="@drawable/ic_white_printer" />
<TextView
android:id="@+id/toolbar_app_name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:layout_marginEnd="16dp"
android:layout_toStartOf="@+id/toolbar_more"
android:layout_toEndOf="@+id/toolbar_icon"
android:ellipsize="end"
android:maxLines="2"
android:text="Test app"
android:textColor="@color/colorWhite"
android:textSize="24sp"
android:textStyle="bold" />
<ImageView
android:id="@+id/toolbar_more"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_alignParentEnd="true"
android:background="?attr/actionBarItemBackground"
android:paddingStart="16dp"
android:paddingEnd="16dp"
app:srcCompat="@drawable/ic_white_more_vertical" />
</RelativeLayout>
</androidx.appcompat.widget.Toolbar>
<Spinner
android:id="@+id/spinner_printer_type"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:dropDownVerticalOffset="35dp"
android:gravity="end"
android:layout_margin="16dp"
app:backgroundTint="@color/standardBlue"
app:layout_constraintTop_toBottomOf="@+id/toolbar"
app:layout_constraintStart_toStartOf="parent"/>
<Spinner
android:id="@+id/spinner_roll_type"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:dropDownVerticalOffset="35dp"
android:gravity="end"
android:layout_marginStart="16dp"
app:layout_constraintHorizontal_bias="1"
app:backgroundTint="@color/standardBlue"
app:layout_constraintStart_toEndOf="@+id/spinner_printer_type"
app:layout_constraintBottom_toBottomOf="@+id/spinner_printer_type"
app:layout_constraintTop_toTopOf="@+id/spinner_printer_type"/>
<Button
android:id="@+id/btn_upload"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="16dp"
android:background="@color/colorAccent"
android:text="upload"
android:textColor="@color/colorWhite"
app:layout_constraintBottom_toBottomOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
您可以自己尝试使用
debugImplementation 'com.squareup.leakcanary:leakcanary-android:2.6'
日志：
┬───
│ GC Root: Global variable in native code
│
├─ android.view.RenderNodeAnimator instance
│ Leaking: NO (MaterialButton↓ is not leaking)
│ ↓ RenderNodeAnimator.mTarget
├─ android.view.RenderNode instance
│ Leaking: NO (MaterialButton↓ is not leaking)
│ ↓ RenderNode.mOwningView
├─ com.google.android.material.button.MaterialButton instance
│ Leaking: NO (ConstraintLayout↓ is not leaking and View attached)
│ View is part of a window view hierarchy
│ View.mAttachInfo is not null (view attached)
│ View.mID = R.id.btn_upload
│ View.mWindowAttachCount = 1
│ mContext instance of com.example.smartlabels.MainActivity with
│ mDestroyed = false
│ ↓ View.mParent
├─ androidx.constraintlayout.widget.ConstraintLayout instance
│ Leaking: NO (AppCompatSpinner↓ is not leaking and View attached)
│ View is part of a window view hierarchy
│ View.mAttachInfo is not null (view attached)
│ View.mWindowAttachCount = 1
│ mContext instance of com.example.smartlabels.MainActivity with
│ mDestroyed = false
│ ↓ ViewGroup.mChildren
├─ android.view.View[] array
│ Leaking: NO (AppCompatSpinner↓ is not leaking)
│ ↓ View[].[1]
├─ androidx.appcompat.widget.AppCompatSpinner instance
│ Leaking: NO (View attached)
│ View is part of a window view hierarchy
│ View.mAttachInfo is not null (view attached)
│ View.mID = R.id.spinner_printer_type
│ View.mWindowAttachCount = 1
│ mPopupContext instance of com.example.smartlabels.MainActivity
│ with mDestroyed = false
│ mContext instance of com.example.smartlabels.MainActivity with
│ mDestroyed = false
│ ↓ AppCompatSpinner.mPopup
│ ~~~~~~
├─ androidx.appcompat.widget.AppCompatSpinner$DropdownPopup instance
│ Leaking: UNKNOWN
│ Retaining 14.8 kB in 245 objects
│ mContext instance of com.example.smartlabels.MainActivity with
│ mDestroyed = false
│ ↓ ListPopupWindow.mPopup
│ ~~~~~~
├─ androidx.appcompat.widget.AppCompatPopupWindow instance
│ Leaking: UNKNOWN
│ Retaining 8.8 kB in 154 objects
│ mContext instance of com.example.smartlabels.MainActivity with
│ mDestroyed = false
│ ↓ PopupWindow.mEnterTransition
│ ~~~~~~~~~~~~~~~~
├─ android.transition.TransitionSet instance
│ Leaking: UNKNOWN
│ Retaining 2.9 kB in 76 objects
│ ↓ Transition.mTargets
│ ~~~~~~~~
├─ java.util.ArrayList instance
│ Leaking: UNKNOWN
│ Retaining 60 B in 2 objects
│ ↓ ArrayList.elementData
│ ~~~~~~~~~~~
├─ java.lang.Object[] array
│ Leaking: UNKNOWN
│ Retaining 40 B in 1 objects
│ ↓ Object[].[0]
│ ~~~
├─ android.widget.PopupWindow$PopupBackgroundView instance
│ Leaking: UNKNOWN
│ Retaining 4.2 kB in 35 objects
│ View not part of a window view hierarchy
│ View.mAttachInfo is null (view detached)
│ View.mWindowAttachCount = 1
│ mContext instance of com.example.smartlabels.MainActivity with
│ mDestroyed = false
│ ↓ View.mParent
│ ~~~~~~~
╰→ android.widget.PopupWindow$PopupDecorView instance
Leaking: YES (ObjectWatcher was watching this because android.widget.
PopupWindow$PopupDecorView received View#onDetachedFromWindow() callback)
Retaining 2.3 kB in 23 objects
key = 8914b38a-5678-4920-89b9-160635defdc7
watchDurationMillis = 552488
retainedDurationMillis = 547487
View not part of a window view hierarchy
View.mAttachInfo is null (view detached)
View.mWindowAttachCount = 1
mContext instance of com.example.smartlabels.MainActivity with
mDestroyed = false
METADATA
Build.VERSION.SDK_INT: 27
Build.MANUFACTURER: Google
LeakCanary version: 2.6
App process name: com.example.smartlabels
Stats: LruCache[maxSize=3000,hits=1393,misses=26800,hitRate=4%]
RandomAccess[bytes=1377952,reads=26800,travel=7146276921,range=9328169,size=1209
4081]
Heap dump reason: user request
Analysis duration: 3014 ms
这是 LeakCanary 2.6 中的已知问题，已在 LeakCanary 2.7 中修复
https://square.github.io/leakcanary/changelog/#finer-grained-root-view-watching
In version 2.6, LeakCanary added detection of root views retained after View.onDetachedFromWindow(). This helps find more leaks, but unfortunately some Android widgets keep a detached root view around to reattach it later (e.g. spinner). App developers also sometimes do the same with dialogs, keeping a single instance around and calling show() and hide() as needed. As a result, LeakCanary would report leaks that were actually not leaks.
In version 2.7, the default behavior changed: LeakCanary will continue to detect leaks of toasts, but will ignore root views created by a PopupWindow (which is what Android widgets use). It will also ignore root views created by a dialog by default, and you can turn this back on by setting the leak_canary_watcher_watch_dismissed_dialogs resource boolean to true:
我的 MainActivity 中的代码为零，只有我创建的 XML 布局和 Spinner 正在泄漏，不确定为什么会发生这种情况或如何解决此问题。有谁知道为什么？我正在使用 LeakCanary 库
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
}
我的 XML 布局 activity_main：
在我的 mainactivity.java
中没有添加任何其他内容<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="MainActivity">
<androidx.appcompat.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="@color/colorPrimary"
android:elevation="4dp"
app:contentInsetStart="0dp"
app:layout_collapseMode="pin"
app:layout_constraintTop_toTopOf="parent">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:id="@+id/toolbar_icon"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:background="?attr/actionBarItemBackground"
android:paddingStart="12dp"
android:paddingEnd="3dp"
app:srcCompat="@drawable/ic_white_printer" />
<TextView
android:id="@+id/toolbar_app_name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:layout_marginEnd="16dp"
android:layout_toStartOf="@+id/toolbar_more"
android:layout_toEndOf="@+id/toolbar_icon"
android:ellipsize="end"
android:maxLines="2"
android:text="Test app"
android:textColor="@color/colorWhite"
android:textSize="24sp"
android:textStyle="bold" />
<ImageView
android:id="@+id/toolbar_more"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_alignParentEnd="true"
android:background="?attr/actionBarItemBackground"
android:paddingStart="16dp"
android:paddingEnd="16dp"
app:srcCompat="@drawable/ic_white_more_vertical" />
</RelativeLayout>
</androidx.appcompat.widget.Toolbar>
<Spinner
android:id="@+id/spinner_printer_type"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:dropDownVerticalOffset="35dp"
android:gravity="end"
android:layout_margin="16dp"
app:backgroundTint="@color/standardBlue"
app:layout_constraintTop_toBottomOf="@+id/toolbar"
app:layout_constraintStart_toStartOf="parent"/>
<Spinner
android:id="@+id/spinner_roll_type"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:dropDownVerticalOffset="35dp"
android:gravity="end"
android:layout_marginStart="16dp"
app:layout_constraintHorizontal_bias="1"
app:backgroundTint="@color/standardBlue"
app:layout_constraintStart_toEndOf="@+id/spinner_printer_type"
app:layout_constraintBottom_toBottomOf="@+id/spinner_printer_type"
app:layout_constraintTop_toTopOf="@+id/spinner_printer_type"/>
<Button
android:id="@+id/btn_upload"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="16dp"
android:background="@color/colorAccent"
android:text="upload"
android:textColor="@color/colorWhite"
app:layout_constraintBottom_toBottomOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
您可以自己尝试使用
debugImplementation 'com.squareup.leakcanary:leakcanary-android:2.6'
日志：
┬───
│ GC Root: Global variable in native code
│
├─ android.view.RenderNodeAnimator instance
│ Leaking: NO (MaterialButton↓ is not leaking)
│ ↓ RenderNodeAnimator.mTarget
├─ android.view.RenderNode instance
│ Leaking: NO (MaterialButton↓ is not leaking)
│ ↓ RenderNode.mOwningView
├─ com.google.android.material.button.MaterialButton instance
│ Leaking: NO (ConstraintLayout↓ is not leaking and View attached)
│ View is part of a window view hierarchy
│ View.mAttachInfo is not null (view attached)
│ View.mID = R.id.btn_upload
│ View.mWindowAttachCount = 1
│ mContext instance of com.example.smartlabels.MainActivity with
│ mDestroyed = false
│ ↓ View.mParent
├─ androidx.constraintlayout.widget.ConstraintLayout instance
│ Leaking: NO (AppCompatSpinner↓ is not leaking and View attached)
│ View is part of a window view hierarchy
│ View.mAttachInfo is not null (view attached)
│ View.mWindowAttachCount = 1
│ mContext instance of com.example.smartlabels.MainActivity with
│ mDestroyed = false
│ ↓ ViewGroup.mChildren
├─ android.view.View[] array
│ Leaking: NO (AppCompatSpinner↓ is not leaking)
│ ↓ View[].[1]
├─ androidx.appcompat.widget.AppCompatSpinner instance
│ Leaking: NO (View attached)
│ View is part of a window view hierarchy
│ View.mAttachInfo is not null (view attached)
│ View.mID = R.id.spinner_printer_type
│ View.mWindowAttachCount = 1
│ mPopupContext instance of com.example.smartlabels.MainActivity
│ with mDestroyed = false
│ mContext instance of com.example.smartlabels.MainActivity with
│ mDestroyed = false
│ ↓ AppCompatSpinner.mPopup
│ ~~~~~~
├─ androidx.appcompat.widget.AppCompatSpinner$DropdownPopup instance
│ Leaking: UNKNOWN
│ Retaining 14.8 kB in 245 objects
│ mContext instance of com.example.smartlabels.MainActivity with
│ mDestroyed = false
│ ↓ ListPopupWindow.mPopup
│ ~~~~~~
├─ androidx.appcompat.widget.AppCompatPopupWindow instance
│ Leaking: UNKNOWN
│ Retaining 8.8 kB in 154 objects
│ mContext instance of com.example.smartlabels.MainActivity with
│ mDestroyed = false
│ ↓ PopupWindow.mEnterTransition
│ ~~~~~~~~~~~~~~~~
├─ android.transition.TransitionSet instance
│ Leaking: UNKNOWN
│ Retaining 2.9 kB in 76 objects
│ ↓ Transition.mTargets
│ ~~~~~~~~
├─ java.util.ArrayList instance
│ Leaking: UNKNOWN
│ Retaining 60 B in 2 objects
│ ↓ ArrayList.elementData
│ ~~~~~~~~~~~
├─ java.lang.Object[] array
│ Leaking: UNKNOWN
│ Retaining 40 B in 1 objects
│ ↓ Object[].[0]
│ ~~~
├─ android.widget.PopupWindow$PopupBackgroundView instance
│ Leaking: UNKNOWN
│ Retaining 4.2 kB in 35 objects
│ View not part of a window view hierarchy
│ View.mAttachInfo is null (view detached)
│ View.mWindowAttachCount = 1
│ mContext instance of com.example.smartlabels.MainActivity with
│ mDestroyed = false
│ ↓ View.mParent
│ ~~~~~~~
╰→ android.widget.PopupWindow$PopupDecorView instance
Leaking: YES (ObjectWatcher was watching this because android.widget.
PopupWindow$PopupDecorView received View#onDetachedFromWindow() callback)
Retaining 2.3 kB in 23 objects
key = 8914b38a-5678-4920-89b9-160635defdc7
watchDurationMillis = 552488
retainedDurationMillis = 547487
View not part of a window view hierarchy
View.mAttachInfo is null (view detached)
View.mWindowAttachCount = 1
mContext instance of com.example.smartlabels.MainActivity with
mDestroyed = false
METADATA
Build.VERSION.SDK_INT: 27
Build.MANUFACTURER: Google
LeakCanary version: 2.6
App process name: com.example.smartlabels
Stats: LruCache[maxSize=3000,hits=1393,misses=26800,hitRate=4%]
RandomAccess[bytes=1377952,reads=26800,travel=7146276921,range=9328169,size=1209
4081]
Heap dump reason: user request
Analysis duration: 3014 ms
这是 LeakCanary 2.6 中的已知问题，已在 LeakCanary 2.7 中修复
https://square.github.io/leakcanary/changelog/#finer-grained-root-view-watching
In version 2.6, LeakCanary added detection of root views retained after View.onDetachedFromWindow(). This helps find more leaks, but unfortunately some Android widgets keep a detached root view around to reattach it later (e.g. spinner). App developers also sometimes do the same with dialogs, keeping a single instance around and calling show() and hide() as needed. As a result, LeakCanary would report leaks that were actually not leaks.
In version 2.7, the default behavior changed: LeakCanary will continue to detect leaks of toasts, but will ignore root views created by a PopupWindow (which is what Android widgets use). It will also ignore root views created by a dialog by default, and you can turn this back on by setting the leak_canary_watcher_watch_dismissed_dialogs resource boolean to true: