Android 如何处理反压函数的异常
我想将城市数组从列表活动返回到主活动。单击“上一步”，将调用BackPressed fucniton。我收到以下例外情况。请帮忙解决这个问题。我不明白为什么会出现异常Android 如何处理反压函数的异常,android,Android,我想将城市数组从列表活动返回到主活动。单击“上一步”，将调用BackPressed fucniton。我收到以下例外情况。请帮忙解决这个问题。我不明白为什么会出现异常 04/21 20:50:42: Launching 'app' on Pixel_3a_API_30_x86. Install successfully finished in 1 s 36 ms. $ adb shell am start -n "com.example.worldclocktest/com.exam
04/21 20:50:42: Launching 'app' on Pixel_3a_API_30_x86.
Install successfully finished in 1 s 36 ms.
$ adb shell am start -n "com.example.worldclocktest/com.example.worldclocktest.MainActivity" -a android.intent.action.MAIN -c android.intent.category.LAUNCHER -D
Waiting for application to come online: com.example.worldclocktest | com.example.worldclocktest.test
Waiting for application to come online: com.example.worldclocktest | com.example.worldclocktest.test
Connected to process 11980 on device 'emulator-5554'.
Connecting to com.example.worldclocktest
Connected to the target VM, address: 'localhost:49972', transport: 'socket'
Capturing and displaying logcat messages from application. This behavior can be disabled in the "Logcat output" section of the "Debugger" settings page.
I/.worldclocktes: Not late-enabling -Xcheck:jni (already on)
I/.worldclocktes: Unquickening 12 vdex files!
W/.worldclocktes: Unexpected CPU variant for X86 using defaults: x86
W/ActivityThread: Application com.example.worldclocktest is waiting for the debugger on port 8100...
I/System.out: Sending WAIT chunk
I/System.out: Debugger has connected
waiting for debugger to settle...
I/System.out: waiting for debugger to settle...
I/System.out: waiting for debugger to settle...
I/System.out: waiting for debugger to settle...
I/System.out: waiting for debugger to settle...
I/System.out: waiting for debugger to settle...
I/chatty: uid=10153(com.example.worldclocktest) identical 3 lines
I/System.out: waiting for debugger to settle...
I/System.out: debugger has settled (1402)
D/NetworkSecurityConfig: No Network Security Config specified, using platform default
D/NetworkSecurityConfig: No Network Security Config specified, using platform default
D/libEGL: loaded /vendor/lib/egl/libEGL_emulation.so
D/libEGL: loaded /vendor/lib/egl/libGLESv1_CM_emulation.so
D/libEGL: loaded /vendor/lib/egl/libGLESv2_emulation.so
W/.worldclocktes: Accessing hidden method Landroid/view/View;->computeFitSystemWindows(Landroid/graphics/Rect;Landroid/graphics/Rect;)Z (greylist, reflection, allowed)
W/.worldclocktes: Accessing hidden method Landroid/view/ViewGroup;->makeOptionalFitsSystemWindows()V (greylist, reflection, allowed)
D/CompatibilityChangeReporter: Compat change id reported: 147798919; UID 10153; state: ENABLED
D/HostConnection: HostConnection::get() New Host Connection established 0xf07622f0, tid 12035
D/HostConnection: HostComposition ext ANDROID_EMU_CHECKSUM_HELPER_v1 ANDROID_EMU_native_sync_v2 ANDROID_EMU_native_sync_v3 ANDROID_EMU_native_sync_v4 ANDROID_EMU_dma_v1 ANDROID_EMU_direct_mem ANDROID_EMU_host_composition_v1 ANDROID_EMU_host_composition_v2 ANDROID_EMU_vulkan ANDROID_EMU_deferred_vulkan_commands ANDROID_EMU_vulkan_null_optional_strings ANDROID_EMU_vulkan_create_resources_with_requirements ANDROID_EMU_YUV_Cache ANDROID_EMU_async_unmap_buffer ANDROID_EMU_vulkan_ignored_handles ANDROID_EMU_vulkan_free_memory_sync ANDROID_EMU_vulkan_shader_float16_int8 ANDROID_EMU_vulkan_async_queue_submit GL_OES_vertex_array_object GL_KHR_texture_compression_astc_ldr ANDROID_EMU_host_side_tracing ANDROID_EMU_async_frame_commands ANDROID_EMU_gles_max_version_2
W/OpenGLRenderer: Failed to choose config with EGL_SWAP_BEHAVIOR_PRESERVED, retrying without...
D/EGL_emulation: eglCreateContext: 0xf0760680: maj 2 min 0 rcv 2
D/EGL_emulation: eglMakeCurrent: 0xf0760680: ver 2 0 (tinfo 0xf0aa4890) (first time)
I/Gralloc4: mapper 4.x is not supported
D/HostConnection: createUnique: call
D/HostConnection: HostConnection::get() New Host Connection established 0xf0760b50, tid 12035
D/goldfish-address-space: allocate: Ask for block of size 0x100
allocate: ioctl allocate returned offset 0x3fddf7000 size 0x2000
D/HostConnection: HostComposition ext ANDROID_EMU_CHECKSUM_HELPER_v1 ANDROID_EMU_native_sync_v2 ANDROID_EMU_native_sync_v3 ANDROID_EMU_native_sync_v4 ANDROID_EMU_dma_v1 ANDROID_EMU_direct_mem ANDROID_EMU_host_composition_v1 ANDROID_EMU_host_composition_v2 ANDROID_EMU_vulkan ANDROID_EMU_deferred_vulkan_commands ANDROID_EMU_vulkan_null_optional_strings ANDROID_EMU_vulkan_create_resources_with_requirements ANDROID_EMU_YUV_Cache ANDROID_EMU_async_unmap_buffer ANDROID_EMU_vulkan_ignored_handles ANDROID_EMU_vulkan_free_memory_sync ANDROID_EMU_vulkan_shader_float16_int8 ANDROID_EMU_vulkan_async_queue_submit GL_OES_vertex_array_object GL_KHR_texture_compression_astc_ldr ANDROID_EMU_host_side_tracing ANDROID_EMU_async_frame_commands ANDROID_EMU_gles_max_version_2
I/OpenGLRenderer: Davey! duration=913ms; Flags=1, IntendedVsync=9353286500214, Vsync=9353303166880, OldestInputEvent=9223372036854775807, NewestInputEvent=0, HandleInputStart=9353318462900, AnimationStart=9353318563300, PerformTraversalsStart=9353318708000, DrawStart=9353916831300, SyncQueued=9354023196600, SyncStart=9354026808400, IssueDrawCommandsStart=9354027022900, SwapBuffers=9354179353500, FrameCompleted=9354203513900, DequeueBufferDuration=714400, QueueBufferDuration=2396600, GpuCompleted=0,
I/Choreographer: Skipped 71 frames! The application may be doing too much work on its main thread.
I/OpenGLRenderer: Davey! duration=1272ms; Flags=0, IntendedVsync=9353369863458, Vsync=9354553196744, OldestInputEvent=9223372036854775807, NewestInputEvent=0, HandleInputStart=9354567730700, AnimationStart=9354567812200, PerformTraversalsStart=9354571817900, DrawStart=9354604811700, SyncQueued=9354619337800, SyncStart=9354621066800, IssueDrawCommandsStart=9354621260400, SwapBuffers=9354622663000, FrameCompleted=9354643884500, DequeueBufferDuration=1351500, QueueBufferDuration=2212000, GpuCompleted=0,
I/Choreographer: Skipped 73 frames! The application may be doing too much work on its main thread.
I/OpenGLRenderer: Davey! duration=4166ms; Flags=1, IntendedVsync=9359186532522, Vsync=9360403199140, OldestInputEvent=9223372036854775807, NewestInputEvent=0, HandleInputStart=9360407707800, AnimationStart=9360407990300, PerformTraversalsStart=9360419610500, DrawStart=9363110900400, SyncQueued=9363224237300, SyncStart=9363247164400, IssueDrawCommandsStart=9363249208500, SwapBuffers=9363361606000, FrameCompleted=9363376311800, DequeueBufferDuration=782000, QueueBufferDuration=2923300, GpuCompleted=0,
I/Choreographer: Skipped 170 frames! The application may be doing too much work on its main thread.
I/OpenGLRenderer: Davey! duration=2967ms; Flags=0, IntendedVsync=9360586458070, Vsync=9363419791290, OldestInputEvent=9223372036854775807, NewestInputEvent=0, HandleInputStart=9363435071400, AnimationStart=9363435164200, PerformTraversalsStart=9363436271200, DrawStart=9363465840400, SyncQueued=9363521938100, SyncStart=9363523985500, IssueDrawCommandsStart=9363524279700, SwapBuffers=9363535387100, FrameCompleted=9363555823300, DequeueBufferDuration=1682200, QueueBufferDuration=1067900, GpuCompleted=0,
I/OpenGLRenderer: Davey! duration=3043ms; Flags=0, IntendedVsync=9360586458070, Vsync=9363419791290, OldestInputEvent=9223372036854775807, NewestInputEvent=0, HandleInputStart=9363435071400, AnimationStart=9363435164200, PerformTraversalsStart=9363436271200, DrawStart=9363541980500, SyncQueued=9363604908500, SyncStart=9363613891500, IssueDrawCommandsStart=9363614201100, SwapBuffers=9363618016700, FrameCompleted=9363638905300, DequeueBufferDuration=1559100, QueueBufferDuration=16988700, GpuCompleted=0,
E/InputEventSender: Exception dispatching finished signal.
E/MessageQueue-JNI: Exception in MessageQueue callback: handleReceiveCallback
E/MessageQueue-JNI: java.lang.RuntimeException: Parcel: unable to marshal value com.example.worldclocktest.City@b72de91
at android.os.Parcel.writeValue(Parcel.java:1885)
at android.os.Parcel.writeList(Parcel.java:1092)
at android.os.Parcel.writeValue(Parcel.java:1832)
at android.os.Parcel.writeArrayMapInternal(Parcel.java:975)
at android.os.BaseBundle.writeToParcelInner(BaseBundle.java:1620)
at android.os.Bundle.writeToParcel(Bundle.java:1303)
at android.os.Parcel.writeBundle(Parcel.java:1044)
at android.content.Intent.writeToParcel(Intent.java:10855)
at android.app.IActivityTaskManager$Stub$Proxy.finishActivity(IActivityTaskManager.java:4260)
at android.app.Activity.finish(Activity.java:6376)
at android.app.Activity.finish(Activity.java:6412)
at android.app.Activity.finishAfterTransition(Activity.java:6469)
at android.app.Activity.onBackPressed(Activity.java:3833)
at androidx.activity.ComponentActivity.access$001(ComponentActivity.java:50)
at androidx.activity.ComponentActivity$1.run(ComponentActivity.java:72)
at androidx.activity.OnBackPressedDispatcher.onBackPressed(OnBackPressedDispatcher.java:194)
at androidx.activity.ComponentActivity.onBackPressed(ComponentActivity.java:286)
at com.example.worldclocktest.ListActivity.onBackPressed(ListActivity.java:90)
at android.app.Activity.onKeyUp(Activity.java:3784)
at android.view.KeyEvent.dispatch(KeyEvent.java:2866)
at android.app.Activity.dispatchKeyEvent(Activity.java:4090)
at androidx.core.app.ComponentActivity.superDispatchKeyEvent(ComponentActivity.java:122)
at androidx.core.view.KeyEventDispatcher.dispatchKeyEvent(KeyEventDispatcher.java:84)
at androidx.core.app.ComponentActivity.dispatchKeyEvent(ComponentActivity.java:140)
at androidx.appcompat.app.AppCompatActivity.dispatchKeyEvent(AppCompatActivity.java:569)
at androidx.appcompat.view.WindowCallbackWrapper.dispatchKeyEvent(WindowCallbackWrapper.java:59)
at androidx.appcompat.app.AppCompatDelegateImpl$AppCompatWindowCallback.dispatchKeyEvent(AppCompatDelegateImpl.java:3054)
at com.android.internal.policy.DecorView.dispatchKeyEvent(DecorView.java:390)
at android.view.ViewRootImpl$ViewPostImeInputStage.processKeyEvent(ViewRootImpl.java:5947)
at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:5815)
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:5310)
at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:5367)
at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:5333)
at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:5485)
at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:5341)
at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:5542)
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:5314)
at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:5367)
at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:5333)
at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:5341)
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:5314)
at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:5367)
at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:5333)
at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:5518)
at android.view.ViewRootImpl$ImeInputStage.onFinishedInputEvent(ViewRootImpl.java:5676)
at android.view.inputmethod.InputMethodManager$PendingEvent.run(InputMethodManager.java:3179)
at android.view.inputmethod.InputMethodManager.invokeFinishedInputEventCallback(InputMethodManager.java:2721)
at android.view.inputmethod.InputMethodManager.finishedInputEvent(InputMethodManager.java:2712)
at android.view.inputmethod.InputMethodManager$ImeInputEventSender.onInputEventFinished(InputMethodManager.java:3156)
at android.view.InputEventSender.dispatchInputEventFinished(InputEventSender.java:143)
at android.os.MessageQueue.nativePollOnce(Native Method)
at android.os.MessageQueue.next(MessageQueue.java:335)
at android.os.Looper.loop(Looper.java:183)
at android.app.ActivityThread.main(ActivityThread.java:7656)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)
D/AndroidRuntime: Shutting down VM
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.worldclocktest, PID: 11980
java.lang.RuntimeException: Parcel: unable to marshal value com.example.worldclocktest.City@b72de91
at android.os.Parcel.writeValue(Parcel.java:1885)
at android.os.Parcel.writeList(Parcel.java:1092)
at android.os.Parcel.writeValue(Parcel.java:1832)
at android.os.Parcel.writeArrayMapInternal(Parcel.java:975)
at android.os.BaseBundle.writeToParcelInner(BaseBundle.java:1620)
at android.os.Bundle.writeToParcel(Bundle.java:1303)
at android.os.Parcel.writeBundle(Parcel.java:1044)
at android.content.Intent.writeToParcel(Intent.java:10855)
at android.app.IActivityTaskManager$Stub$Proxy.finishActivity(IActivityTaskManager.java:4260)
at android.app.Activity.finish(Activity.java:6376)
at android.app.Activity.finish(Activity.java:6412)
at android.app.Activity.finishAfterTransition(Activity.java:6469)
at android.app.Activity.onBackPressed(Activity.java:3833)
at androidx.activity.ComponentActivity.access$001(ComponentActivity.java:50)
at androidx.activity.ComponentActivity$1.run(ComponentActivity.java:72)
at androidx.activity.OnBackPressedDispatcher.onBackPressed(OnBackPressedDispatcher.java:194)
at androidx.activity.ComponentActivity.onBackPressed(ComponentActivity.java:286)
at com.example.worldclocktest.ListActivity.onBackPressed(ListActivity.java:90)
at android.app.Activity.onKeyUp(Activity.java:3784)
at android.view.KeyEvent.dispatch(KeyEvent.java:2866)
at android.app.Activity.dispatchKeyEvent(Activity.java:4090)
at androidx.core.app.ComponentActivity.superDispatchKeyEvent(ComponentActivity.java:122)
at androidx.core.view.KeyEventDispatcher.dispatchKeyEvent(KeyEventDispatcher.java:84)
at androidx.core.app.ComponentActivity.dispatchKeyEvent(ComponentActivity.java:140)
at androidx.appcompat.app.AppCompatActivity.dispatchKeyEvent(AppCompatActivity.java:569)
at androidx.appcompat.view.WindowCallbackWrapper.dispatchKeyEvent(WindowCallbackWrapper.java:59)
at androidx.appcompat.app.AppCompatDelegateImpl$AppCompatWindowCallback.dispatchKeyEvent(AppCompatDelegateImpl.java:3054)
at com.android.internal.policy.DecorView.dispatchKeyEvent(DecorView.java:390)
at android.view.ViewRootImpl$ViewPostImeInputStage.processKeyEvent(ViewRootImpl.java:5947)
at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:5815)
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:5310)
at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:5367)
at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:5333)
at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:5485)
at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:5341)
at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:5542)
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:5314)
at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:5367)
at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:5333)
at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:5341)
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:5314)
at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:5367)
at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:5333)
at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:5518)
at android.view.ViewRootImpl$ImeInputStage.onFinishedInputEvent(ViewRootImpl.java:5676)
at android.view.inputmethod.InputMethodManager$PendingEvent.run(InputMethodManager.java:3179)
at android.view.inputmethod.InputMethodManager.invokeFinishedInputEventCallback(InputMethodManager.java:2721)
at android.view.inputmethod.InputMethodManager.finishedInputEvent(InputMethodManager.java:2712)
at android.view.inputmethod.InputMethodManager$ImeInputEventSender.onInputEventFinished(InputMethodManager.java:3156)
at android.view.InputEventSender.dispatchInputEventFinished(InputEventSender.java:143)
E/AndroidRuntime: at android.os.MessageQueue.nativePollOnce(Native Method)
at android.os.MessageQueue.next(MessageQueue.java:335)
at android.os.Looper.loop(Looper.java:183)
at android.app.ActivityThread.main(ActivityThread.java:7656)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)
I/Process: Sending signal. PID: 11980 SIG: 9
Disconnected from the target VM, address: 'localhost:49972', transport: 'socket'
package com.example.worldclocktest;
import ...
public class ListActivity extends AppCompatActivity {
ArrayList<City> cities;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
showMessage("List Activity Created");
cities = new ArrayList<City>();
create_City_list();
create_View();
}
private void showMessage(String message) {
Toast toast = Toast.makeText(this, message, Toast.LENGTH_LONG);
toast.show();
}
private void create_City_list() {
City city1 = new City("Lahore","8:00pm");
City city2 = new City("Karachi","7:00pm");
City city3 = new City("Islamabad","9:00pm");
City city4 = new City("NewYork","10:00pm");
City city5 = new City("Istanbul","11:00pm");
City city6 = new City("Venus","2:00pm");
City city7= new City("San Francisco","3:00pm");
City city8 = new City("London","8:00pm");
City city9 = new City("Belgium","5:00pm");
City city10 = new City("Delhi","9:00pm");
City city11 = new City("Multan","10:00pm");
City city12 = new City("Toronto","9:00pm");
City city13 = new City("Dubai","1:00pm");
City city14 = new City("Singapore","4:00pm");
City city15 = new City("Moscow","7:00pm");
cities.add(city1);
cities.add(city2);
cities.add(city3);
cities.add(city4);
cities.add(city5);
cities.add(city6);
cities.add(city7);
cities.add(city8);
cities.add(city9);
cities.add(city10);
cities.add(city11);
cities.add(city12);
cities.add(city13);
cities.add(city14);
cities.add(city15);
}
private void create_View() {
setContentView(R.layout.activity_list);
ListView view = (ListView) findViewById(R.id.view_list);
CityListAdapter adapter= new CityListAdapter(this,R.layout.adapter_view,cities);
view.setAdapter(adapter);
Attach_Text_Listener(adapter);
}
@Override
public void onBackPressed() {
showMessage("Back Pressed");
Intent intent = new Intent();
intent.putExtra("list",cities);
setResult(RESULT_OK, intent);
super.onBackPressed();
}
}
package com.example.worldclocktest；
导入。。。
公共类ListActivity扩展了AppCompatActivity{
阵列式城市；
@凌驾
创建时受保护的void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
showMessage（“创建的列表活动”）；
城市=新阵列列表（）；
创建城市列表（）；
创建_视图（）；
}
私有void showMessage（字符串消息）{
Toast Toast=Toast.makeText（这个，消息，Toast.LENGTH\u LONG）；
toast.show（）；
}
私有void创建城市列表（）{
城市1=新城（“拉合尔”，“晚上8:00”）；
城市2=新城（“卡拉奇”，“下午7:00”）；
城市3=新城（“伊斯兰堡”，“晚上9:00”）；
City city4=纽约（“纽约”，“晚上10:00”）；
城市5=新城（“伊斯坦布尔”，“晚上11:00”）；
城市6=新城（“维纳斯”，“下午2:00”）；
City city7=新城（“旧金山”，“下午3:00”）；
City city8=新城（“伦敦”，“晚上8:00”）；
城市9=新城（“比利时”，“下午5:00”）；
城市10=新市（“德里”，“晚上9:00”）；
城市11=新城（“木尔坦”，“晚上10:00”）；
城市12=新城（“多伦多”，“晚上9:00”）；
城市13=新城（“迪拜”，“下午1:00”）；
城市14=新城（“新加坡”，“下午4:00”）；
城市15=新城（“莫斯科”，“下午7:00”）；
城市。添加（城市1）；
城市。添加（城市2）；
城市。添加（城市3）；
城市。添加（城市4）；
城市。添加（城市5）；
城市。添加（城市6）；
城市。添加（城市7）；
城市。添加（城市8）；
城市。添加（城市9）；
城市。添加（城市10）；
城市。添加（城市11）；
城市。添加（城市12）；
城市。添加（城市13）；
城市。添加（城市14）；
城市。添加（城市15）；
}
私有void创建_视图（）{
setContentView（R.layout.activity_列表）；
ListView视图=（ListView）findViewById（R.id.view\u列表）；
CityListAdapter=新的CityListAdapter（这个，R.layout.adapter\u视图，城市）；
view.setAdapter（适配器）；
附加文本侦听器（适配器）；
}
@凌驾
public void onBackPressed（）{
showMessage（“反压”）；
意图=新意图（）；
意向。putExtra（“列表”，城市）；
设置结果（结果正常，意图）；
super.onBackPressed（）；
}
}
package com.example.worldclocktest;
import ...
public class MainActivity extends AppCompatActivity{
ArrayList<City> selected_cities;
ArrayList<City> cities;
final int REQUEST_CODE = 1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
showMessage("Created");
}
private void showMessage(String message) {
Toast toast = Toast.makeText(this, message, Toast.LENGTH_LONG);
toast.show();
}
public void buttonClick(View v)
{
if (v.getId() == R.id.button_list) {
showMessage("buttonClicked");
list_cities();
}
}
public void list_cities()
{
showMessage("city_list");
Intent intent = new Intent(this, ListActivity.class);
startActivityForResult(intent,REQUEST_CODE);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
showMessage("Activity Result");
//cities = new ArrayList<City>();
super.onActivityResult(requestCode, resultCode, data);
if(requestCode == REQUEST_CODE){
if (resultCode == RESULT_OK) {
cities = (ArrayList<City>) data.getSerializableExtra("list");
showMessage("Selected cities");
/*if (cities.size()!= 0) {
//addselectedcities();
// CreateListView();
}*/
}else {
showMessage("Result Code Problem");
}
}
else {
showMessage("Request Code Problem");
}
}
private void addselectedcities() {
selected_cities = new ArrayList<City>();
if(selected_cities.size()!=0) {
selected_cities.clear();
}
for(int i=0;i<cities.size();i++) {
if(cities.get(i).isImportant()== true) {
selected_cities.add(cities.get(i));
}
}
}
}
package com.example.worldclocktest；
导入。。。
公共类MainActivity扩展了AppCompatActivity{
ArrayList选定的城市；
阵列式城市；
最终int请求_代码=1；
@凌驾
创建时受保护的void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.activity_main）；
showMessage（“已创建”）；
}
私有void showMessage（字符串消息）{
Toast Toast=Toast.makeText（这个，消息，Toast.LENGTH\u LONG）；
toast.show（）；
}
公共无效按钮单击（视图v）
{
if（v.getId（）==R.id.button\u列表）{
显示消息（“按钮点击”）；
列出城市（）；
}
}
公共作废清单(城市)
{
showMessage（“城市列表”）；
Intent Intent=新的Intent（这个，ListActivity.class）；
startActivityForResult（意图、请求代码）；
}
@凌驾
受保护的void onActivityResult（int请求代码、int结果代码、意图数据）{
showMessage（“活动结果”）；
//城市=新阵列列表（）；
super.onActivityResult（请求代码、结果代码、数据）；
if（requestCode==请求\代码）{
if（resultCode==RESULT\u OK）{
cities=（ArrayList）data.getSerializableExtra（“列表”）；
showMessage（“选定城市”）；
/*如果（cities.size（）！=0）{
//添加选定城市（）；
//CreateListView（）；
}*/
}否则{
showMessage（“结果代码问题”）；
}
}
否则{
showMessage（“请求代码问题”）；
}
}
私有void addselectedcities（）{
所选城市=新阵列列表（）；
如果（选定城市。大小（）！=0）{
所选城市。清除（）；
}
对于（int i=0；iCity类可序列化吗？如果不可序列化，它将不会序列化并在运行时抛出错误。让City类实现可序列化接口，它应该可以工作这是否回答了您的问题？