我正在使用BottomNavigationView和Fragment编写应用程序，以通过编程方式更新布局。
我正在尝试使用堆栈来允许用户单击并返回上一个片段。我曾尝试在增加新片段后使用addToBackStack，但是尽管布局正确更改，但按下后退键时，所选项目菜单不会随之改变。
因此，我决定创建一个Fragment的自定义堆栈，并使用setSelectedItemId更改所选项目，但是此操作会使应用程序崩溃。我通常花了很多时间，但我无法理解这种行为。
谢谢您的帮助。
public class MainActivity extends FragmentActivity {
private FragmentManager fm = getSupportFragmentManager();
private Logger logger = Logger.getLogger("global");
private BottomNavigationView bnv;
private CustomStack customStack = new CustomStack();
private BottomNavigationView.OnNavigationItemSelectedListener mOnNavigationItemSelectedListener
= new BottomNavigationView.OnNavigationItemSelectedListener() {
@Override
public boolean onNavigationItemSelected(@NonNull MenuItem item) {
Fragment centerFragment;
switch (item.getItemId()) {
case R.id.navigation_home:
centerFragment = new Fragment1();
replaceCenterLayoutFragment(centerFragment);
customStack.push(centerFragment);
return true;
case R.id.navigation_map:
centerFragment = new Fragment2();
bnv.setSelectedItemId(R.id.navigation_interest);
return true;
case R.id.navigation_interest:
centerFragment = new Fragment3();
replaceCenterLayoutFragment(centerFragment);
customStack.push(centerFragment);
return true;
case R.id.navigation_notifications:
centerFragment = new Fragment4();
replaceCenterLayoutFragment(centerFragment);
customStack.push(centerFragment);
return true;
}
return false;
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
bnv = (BottomNavigationView) findViewById(R.id.navigation);
bnv.setOnNavigationItemSelectedListener(mOnNavigationItemSelectedListener);
FragmentTransaction ft1 = fm.beginTransaction();
Board b = new Board();
ft1.add(R.id.center_layout, new Fragment1()).commit();
customStack.push(b);
}
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
customStack.pop();
replaceCenterLayoutFragment(customStack.top());
}
return false;
}
private void replaceCenterLayoutFragment(Fragment f){
FragmentTransaction ft1 = fm.beginTransaction();
ft1.replace(R.id.center_layout, f).commit();
syncMenuItem(f);
}
private void syncMenuItem(Fragment f){
if(f instanceof Fragment1)
bnv.setSelectedItemId(R.id.p1);
if(f instanceof Fragment2)
bnv.setSelectedItemId(R.id.p2);
if(f instanceof Fragment3)
bnv.setSelectedItemId(R.id.p3);
if(f instanceof Fragment4)
bnv.setSelectedItemId(R.id.p4);
}
}
这是我的自定义堆栈
public class CustomStack {
private ArrayList<Fragment> menu ;
private Logger logger = Logger.getLogger("global");
public CustomStack(){
menu = new ArrayList<>();
}
public void push(Fragment i){
menu.add(i);
}
public Fragment pop (){
if(menu.size() > 0) {
int s = menu.size() -1;
Fragment app = menu.get(s);
menu.remove(s);
return app;
}
else{
return null;
}
}
public Fragment top(){
if(menu.size() > 0)
return menu.get(menu.size() -1);
else
return null;
}
public boolean isEmpty(){
return menu.size() > 0;
}
}
和LogCatPage
07-10 20:31:07.879 28384-28384/? I/art: Late-enabling -Xcheck:jni
07-10 20:31:07.970 28384-28384/com.example.longsky.peoople W/art: Failed execv(/system/bin/dex2oat --runtime-arg -classpath --runtime-arg --instruction-set=arm64 --instruction-set-features=smp,a53 --runtime-arg -Xrelocate --boot-image=/system/framework/boot.art --runtime-arg -Xms64m --runtime-arg -Xmx512m --instruction-set-variant=generic --instruction-set-features=default --dex-file=/data/app/com.example.longsky.peoople-2/split_lib_dependencies_apk.apk --oat-file=/data/dalvik-cache/arm64/data@[email protected]@[email protected]) because non-0 exit status
07-10 20:31:08.145 28384-28384/com.example.longsky.peoople W/art: Failed execv(/system/bin/dex2oat --runtime-arg -classpath --runtime-arg --instruction-set=arm64 --instruction-set-features=smp,a53 --runtime-arg -Xrelocate --boot-image=/system/framework/boot.art --runtime-arg -Xms64m --runtime-arg -Xmx512m --instruction-set-variant=generic --instruction-set-features=default --dex-file=/data/app/com.example.longsky.peoople-2/split_lib_slice_0_apk.apk --oat-file=/data/dalvik-cache/arm64/data@[email protected]@[email protected]) because non-0 exit status
07-10 20:31:08.187 28384-28384/com.example.longsky.peoople W/art: Failed execv(/system/bin/dex2oat --runtime-arg -classpath --runtime-arg --instruction-set=arm64 --instruction-set-features=smp,a53 --runtime-arg -Xrelocate --boot-image=/system/framework/boot.art --runtime-arg -Xms64m --runtime-arg -Xmx512m --instruction-set-variant=generic --instruction-set-features=default --dex-file=/data/app/com.example.longsky.peoople-2/split_lib_slice_1_apk.apk --oat-file=/data/dalvik-cache/arm64/data@[email protected]@[email protected]) because non-0 exit status
07-10 20:31:08.224 28384-28384/com.example.longsky.peoople W/art: Failed execv(/system/bin/dex2oat --runtime-arg -classpath --runtime-arg --instruction-set=arm64 --instruction-set-features=smp,a53 --runtime-arg -Xrelocate --boot-image=/system/framework/boot.art --runtime-arg -Xms64m --runtime-arg -Xmx512m --instruction-set-variant=generic --instruction-set-features=default --dex-file=/data/app/com.example.longsky.peoople-2/split_lib_slice_2_apk.apk --oat-file=/data/dalvik-cache/arm64/data@[email protected]@[email protected]) because non-0 exit status
07-10 20:31:08.264 28384-28384/com.example.longsky.peoople W/art: Failed execv(/system/bin/dex2oat --runtime-arg -classpath --runtime-arg --instruction-set=arm64 --instruction-set-features=smp,a53 --runtime-arg -Xrelocate --boot-image=/system/framework/boot.art --runtime-arg -Xms64m --runtime-arg -Xmx512m --instruction-set-variant=generic --instruction-set-features=default --dex-file=/data/app/com.example.longsky.peoople-2/split_lib_slice_3_apk.apk --oat-file=/data/dalvik-cache/arm64/data@[email protected]@[email protected]) because non-0 exit status
07-10 20:31:08.311 28384-28384/com.example.longsky.peoople W/art: Failed execv(/system/bin/dex2oat --runtime-arg -classpath --runtime-arg --instruction-set=arm64 --instruction-set-features=smp,a53 --runtime-arg -Xrelocate --boot-image=/system/framework/boot.art --runtime-arg -Xms64m --runtime-arg -Xmx512m --instruction-set-variant=generic --instruction-set-features=default --dex-file=/data/app/com.example.longsky.peoople-2/split_lib_slice_4_apk.apk --oat-file=/data/dalvik-cache/arm64/data@[email protected]@[email protected]) because non-0 exit status
07-10 20:31:08.347 28384-28384/com.example.longsky.peoople W/art: Failed execv(/system/bin/dex2oat --runtime-arg -classpath --runtime-arg --instruction-set=arm64 --instruction-set-features=smp,a53 --runtime-arg -Xrelocate --boot-image=/system/framework/boot.art --runtime-arg -Xms64m --runtime-arg -Xmx512m --instruction-set-variant=generic --instruction-set-features=default --dex-file=/data/app/com.example.longsky.peoople-2/split_lib_slice_5_apk.apk --oat-file=/data/dalvik-cache/arm64/data@[email protected]@[email protected]) because non-0 exit status
07-10 20:31:08.387 28384-28384/com.example.longsky.peoople W/art: Failed execv(/system/bin/dex2oat --runtime-arg -classpath --runtime-arg --instruction-set=arm64 --instruction-set-features=smp,a53 --runtime-arg -Xrelocate --boot-image=/system/framework/boot.art --runtime-arg -Xms64m --runtime-arg -Xmx512m --instruction-set-variant=generic --instruction-set-features=default --dex-file=/data/app/com.example.longsky.peoople-2/split_lib_slice_6_apk.apk --oat-file=/data/dalvik-cache/arm64/data@[email protected]@[email protected]) because non-0 exit status
07-10 20:31:08.427 28384-28384/com.example.longsky.peoople W/art: Failed execv(/system/bin/dex2oat --runtime-arg -classpath --runtime-arg --instruction-set=arm64 --instruction-set-features=smp,a53 --runtime-arg -Xrelocate --boot-image=/system/framework/boot.art --runtime-arg -Xms64m --runtime-arg -Xmx512m --instruction-set-variant=generic --instruction-set-features=default --dex-file=/data/app/com.example.longsky.peoople-2/split_lib_slice_7_apk.apk --oat-file=/data/dalvik-cache/arm64/data@[email protected]@[email protected]) because non-0 exit status
07-10 20:31:08.463 28384-28384/com.example.longsky.peoople W/art: Failed execv(/system/bin/dex2oat --runtime-arg -classpath --runtime-arg --instruction-set=arm64 --instruction-set-features=smp,a53 --runtime-arg -Xrelocate --boot-image=/system/framework/boot.art --runtime-arg -Xms64m --runtime-arg -Xmx512m --instruction-set-variant=generic --instruction-set-features=default --dex-file=/data/app/com.example.longsky.peoople-2/split_lib_slice_8_apk.apk --oat-file=/data/dalvik-cache/arm64/data@[email protected]@[email protected]) because non-0 exit status
07-10 20:31:08.508 28384-28384/com.example.longsky.peoople W/art: Failed execv(/system/bin/dex2oat --runtime-arg -classpath --runtime-arg --instruction-set=arm64 --instruction-set-features=smp,a53 --runtime-arg -Xrelocate --boot-image=/system/framework/boot.art --runtime-arg -Xms64m --runtime-arg -Xmx512m --instruction-set-variant=generic --instruction-set-features=default --dex-file=/data/app/com.example.longsky.peoople-2/split_lib_slice_9_apk.apk --oat-file=/data/dalvik-cache/arm64/data@[email protected]@[email protected]) because non-0 exit status
07-10 20:31:08.509 28384-28384/com.example.longsky.peoople W/System: ClassLoader referenced unknown path: /data/app/com.example.longsky.peoople-2/lib/arm64
07-10 20:31:08.512 28384-28384/com.example.longsky.peoople I/InstantRun: starting instant run server: is main process
07-10 20:31:08.600 28384-28384/com.example.longsky.peoople W/art: Before Android 4.1, method android.graphics.PorterDuffColorFilter android.support.graphics.drawable.VectorDrawableCompat.updateTintFilter(android.graphics.PorterDuffColorFilter, android.content.res.ColorStateList, android.graphics.PorterDuff$Mode) would have incorrectly overridden the package-private method in android.graphics.drawable.Drawable
07-10 20:31:08.655 28384-28499/com.example.longsky.peoople E/AbstractTracker: Can't create handler inside thread that has not called Looper.prepare()
07-10 20:31:08.655 28384-28499/com.example.longsky.peoople D/AppTracker: App Event: start
07-10 20:31:08.661 28384-28501/com.example.longsky.peoople D/OpenGLRenderer: Use EGL_SWAP_BEHAVIOR_PRESERVED: true
07-10 20:31:08.679 28384-28501/com.example.longsky.peoople I/Adreno: QUALCOMM build : 183c040, Iff84fb1103
Build Date : 03/18/16
OpenGL ES Shader Compiler Version: XE031.06.00.02
Local Branch :
Remote Branch : refs/tags/AU_LINUX_ANDROID_LA.BF64.1.2.2_RB4.06.00.01.180.031
Remote Branch : NONE
Reconstruct Branch : NOTHING
07-10 20:31:08.686 28384-28501/com.example.longsky.peoople I/OpenGLRenderer: Initialized EGL, version 1.4
07-10 20:31:10.516 28384-28384/com.example.longsky.peoople D/AndroidRuntime: Shutting down VM
07-10 20:31:10.592 28384-28384/com.example.longsky.peoople E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.longsky.peoople, PID: 28384
java.lang.StackOverflowError: stack size 8MB
at com.example.longsky.peoople.MainActivity.replaceCenterLayoutFragment(MainActivity.java:96)
at com.example.longsky.peoople.MainActivity.access$000(MainActivity.java:15)
at com.example.longsky.peoople.MainActivity$1.onNavigationItemSelected(MainActivity.java:39)
at android.support.design.widget.BottomNavigationView$1.onMenuItemSelected(BottomNavigationView.java:184)
at android.support.v7.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:822)
at android.support.v7.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:156)
at android.support.v7.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:969)
at android.support.design.widget.BottomNavigationView.setSelectedItemId(BottomNavigationView.java:341)
at com.example.longsky.peoople.MainActivity.replaceCenterLayoutFragment(MainActivity.java:96)
at com.example.longsky.peoople.MainActivity.access$000(MainActivity.java:15)
at com.example.longsky.peoople.MainActivity$1.onNavigationItemSelected(MainActivity.java:39)
at android.support.design.widget.BottomNavigationView$1.onMenuItemSelected(BottomNavigationView.java:184)
at android.support.v7.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:822)
at android.support.v7.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:156)
at android.support.v7.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:969)
at android.support.design.widget.BottomNavigationView.setSelectedItemId(BottomNavigationView.java:341)
at com.example.longsky.peoople.MainActivity.replaceCenterLayoutFragment(MainActivity.java:96)
at com.example.longsky.peoople.MainActivity.access$000(MainActivity.java:15)
at com.example.longsky.peoople.MainActivity$1.onNavigationItemSelected(MainActivity.java:39)
at android.support.design.widget.BottomNavigationView$1.onMenuItemSelected(BottomNavigationView.java:184)
at android.support.v7.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:822)
at android.support.v7.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:156)
at android.support.v7.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:969)
at android.support.design.widget.BottomNavigationView.setSelectedItemId(BottomNavigationView.java:341)
at com.example.longsky.peoople.MainActivity.replaceCenterLayoutFragment(MainActivity.java:96)
at com.example.longsky.peoople.MainActivity.access$000(MainActivity.java:15)
at com.example.longsky.peoople.MainActivity$1.onNavigationItemSelected(MainActivity.java:39)
at android.support.design.widget.BottomNavigationView$1.onMenuItemSelected(BottomNavigationView.java:184)
at android.support.v7.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:822)
at android.support.v7.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:156)
at android.support.v7.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:969)
at android.support.design.widget.BottomNavigationView.setSelectedItemId(BottomNavigationView.java:341)
at com.example.longsky.peoople.MainActivity.replaceCenterLayoutFragment(MainActivity.java:96)
at com.example.longsky.peoople.MainActivity.access$000(MainActivity.java:15)
at com.example.longsky.peoople.MainActivity$1.onNavigationItemSelected(MainActivity.java:39)
at android.support.design.widget.BottomNavigationView$1.onMenuItemSelected(BottomNavigationView.java:184)
at android.support.v7.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:822)
at android.support.v7.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:156)
at android.support.v7.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:969)
at android.support.design.widget.BottomNavigationView.setSelectedItemId(BottomNavigationView.java:341)
at com.example.longsky.peoople.MainActivity.replaceCenterLayoutFragment(MainActivity.java:96)
at com.example.longsky.peoople.MainActivity.access$000(MainActivity.java:15)
at com.example.longsky.peoople.MainActivity$1.onNavigationItemSelected(MainActivity.java:39)
at android.support.d
07-10 20:31:10.594 28384-28384/com.example.longsky.peoople D/AppTracker: App Event: crash
07-10 20:31:10.638 28384-28384/com.example.longsky.peoople D/Error: ERR: exClass=java.lang.StackOverflowError
07-10 20:31:10.638 28384-28384/com.example.longsky.peoople D/Error: ERR: exMsg=stack size 8MB
07-10 20:31:10.638 28384-28384/com.example.longsky.peoople D/Error: ERR: file=MainActivity.java
07-10 20:31:10.638 28384-28384/com.example.longsky.peoople D/Error: ERR: class=com.example.longsky.peoople.MainActivity
07-10 20:31:10.638 28384-28384/com.example.longsky.peoople D/Error: ERR: method=replaceCenterLayoutFragment line=96
07-10 20:31:10.647 28384-28384/com.example.longsky.peoople D/Error: ERR: stack=java.lang.StackOverflowError: stack size 8MB
at com.example.longsky.peoople.MainActivity.replaceCenterLayoutFragment(MainActivity.java:96)
at com.example.longsky.peoople.MainActivity.access$000(MainActivity.java:15)
at com.example.longsky.peoople.MainActivity$1.onNavigationItemSelected(MainActivity.java:39)
at android.support.design.widget.BottomNavigationView$1.onMenuItemSelected(BottomNavigationView.java:184)
at android.support.v7.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:822)
at android.support.v7.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:156)
at android.support.v7.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:969)
at android.support.design.widget.BottomNavigationView.setSelectedItemId(BottomNavigationView.java:341)
at com.example.longsky.peoople.MainActivity.replaceCenterLayoutFragment(MainActivity.java:96)
at com.example.longsky.peoople.MainActivity.access$000(MainActivity.java:15)
at com.example.longsky.peoople.MainActivity$1.onNavigationItemSelected(MainActivity.java:39)
at android.support.design.widget.BottomNavigationView$1.onMenuItemSelected(BottomNavigationView.java:184)
at android.support.v7.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:822)
at android.support.v7.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:156)
at android.support.v7.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:969)
at android.support.design.widget.BottomNavigationView.setSelectedItemId(BottomNavigationView.java:341)
at com.example.longsky.peoople.MainActivity.replaceCenterLayoutFragment(MainActivity.java:96)
at com.example.longsky.peoople.MainActivity.access$000(MainActivity.java:15)
at com.example.longsky.peoople.MainActivity$1.onNavigationItemSelected(MainActivity.java:39)
at android.support.design.widget.BottomNavigationView$1.onMenuItemSelected(BottomNavigationView.java:184)
at android.support.v7.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:822)
at android.support.v7.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:156)
at android.support.v7.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:969)
at android.support.design.widget.BottomNavigationView.setSelectedItemId(BottomNavigationView.java:341)
at com.example.longsky.peoople.MainActivity.replaceCenterLayoutFragment(MainActivity.java:96)
at com.example.longsky.peoople.MainActivity.access$000(MainActivity.java:15)
at com.example.longsky.peoople.MainActivity$1.onNavigationItemSelected(MainActivity.java:39)
at android.support.design.widget.BottomNavigationView$1.onMenuItemSelected(BottomNavigationView.java:184)
at android.support.v7.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:822)
at android.support.v7.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:156)
at android.support.v7.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:969)
at android.support.design.widget.BottomNavigationView.setSelectedItemId(BottomNavigationView.java:341)
at com.example.longsky.peoople.MainActivity.replaceCenterLayoutFragment(MainActivity.java:96)
at com.example.longsky.peoople.MainActivity.access$000(MainActivity.java:15)
at com.example.longsky.peoople.MainActivity$1.onNavigationItemSelected(MainActivity.java:39)
at android.support.design.widget.BottomNavigationView$1.onMenuItemSelected(BottomNavigationView.java:184)
at android.support.v7.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:822)
at android.support.v7.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:156)
at android.support.v7.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:969)
at android.support.design.widget.BottomNavigationView.setSelectedItemId(BottomNavigationView.java:341)
at com.example.longsky.peoople.MainActivity.replaceCenterLayoutFragment(MainActivity.java:96)
at com.example.longsky.peoople.MainActivity.access$000(MainActivity.java:15)
at com.example.longsky.peoople.MainActivity$1.onNavigationItemSelected(MainActivity.java:39)
at android.support.design.widget.BottomNavigationView$1.onMenuItemSelected(BottomNavigati
07-10 20:31:10.647 28384-28384/com.example.longsky.peoople D/Error: ERR: TOTAL BYTES WRITTEN: 862560
07-10 20:31:10.695 28384-28384/com.example.longsky.peoople I/Process: Sending signal. PID: 28384 SIG: 9
最佳答案
问题是您setSelectedItemId调用了侦听器，该监听器将调用replaceCenterLayoutFragment，这将调用setSelectedItemId，依此类推。
一个hacky的修复方法如下
private void replaceCenterLayoutFragment(Fragment f){
FragmentTransaction ft1 = fm.beginTransaction();
ft1.replace(R.id.center_layout, f).commit();
bnv.setOnNavigationItemSelectedListener(null);
syncMenuItem(f);
bnv.setOnNavigationItemSelectedListener(mOnNavigationItemSelectedListener);
}