我在两个类“MainActivity”和“abc”类之间使用 startActivityForResult 。我遇到的问题是应用程序在启动时不断崩溃，通过阅读 LogCat 我认为崩溃是由于 MainActivity 类中的 NPE“NullPointException”造成的(但我不确定)。我已经搜索了几个小时来寻找解决方案，但找不到解决我的问题的解决方案。
1)MainActivity类:
package com.example.passstrings;
import android.support.v7.app.ActionBarActivity;
import android.support.v4.app.Fragment;
import android.content.Intent;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.TextView;
public class MainActivity extends ActionBarActivity {
Button bt1;
TextView tv2;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tv2 = (TextView) findViewById(R.id.textView2);
bt1=(Button) findViewById(R.id.button1);
bt1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent intent = new Intent(MainActivity.this , abc.class);
startActivityForResult(intent , 0);
}
});
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment())
.commit();
}
}
@Override
protected void onActivityResult(int requestCode , int resultCode , Intent data){
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == RESULT_OK){
Intent intent = getIntent();
String pass= intent.getExtras().getString("key");
tv2.setText(pass);
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
return rootView;
}
}
}
2)abc类
package com.example.passstrings;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.RadioButton;
import android.widget.TextView;
public class abc extends Activity{
TextView tv1;
String setData;
RadioButton r1,r2,r3,r4;
Button bt2;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.abc);
r1 = (RadioButton) findViewById(R.id.radioButton1);
r2 = (RadioButton) findViewById(R.id.RadioButton01);
r3 = (RadioButton) findViewById(R.id.RadioButton02);
r4 = (RadioButton) findViewById(R.id.RadioButton03);
bt2.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if (r1.isChecked() || r2.isChecked() || r3.isChecked() == true){
setData ="Failed";
}else if (r3.isChecked() ==true){
setData="Passed";
}else{
setData="You didn't choose an answer";
}
Intent Int = new Intent(abc.this , MainActivity.class);
Int.putExtra("key", setData);
setResult(RESULT_OK , Int);
finish();
}
});
}
}
3)日志猫:
04-04 14:52:15.406: I/dalvikvm(369): Could not find method android.content.pm.PackageManager.getActivityLogo, referenced from method android.support.v7.internal.widget.ActionBarView.<init>
04-04 14:52:15.415: W/dalvikvm(369): VFY: unable to resolve virtual method 320: Landroid/content/pm/PackageManager;.getActivityLogo (Landroid/content/ComponentName;)Landroid/graphics/drawable/Drawable;
04-04 14:52:15.415: D/dalvikvm(369): VFY: replacing opcode 0x6e at 0x008b
04-04 14:52:15.415: I/dalvikvm(369): Could not find method android.content.pm.ApplicationInfo.loadLogo, referenced from method android.support.v7.internal.widget.ActionBarView.<init>
04-04 14:52:15.415: W/dalvikvm(369): VFY: unable to resolve virtual method 316: Landroid/content/pm/ApplicationInfo;.loadLogo (Landroid/content/pm/PackageManager;)Landroid/graphics/drawable/Drawable;
04-04 14:52:15.415: D/dalvikvm(369): VFY: replacing opcode 0x6e at 0x0099
04-04 14:52:15.425: D/dalvikvm(369): VFY: dead code 0x008e-0092 in Landroid/support/v7/internal/widget/ActionBarView;.<init> (Landroid/content/Context;Landroid/util/AttributeSet;)V
04-04 14:52:15.425: D/dalvikvm(369): VFY: dead code 0x009c-00a0 in Landroid/support/v7/internal/widget/ActionBarView;.<init> (Landroid/content/Context;Landroid/util/AttributeSet;)V
04-04 14:52:15.535: D/AndroidRuntime(369): Shutting down VM
04-04 14:52:15.535: W/dalvikvm(369): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
04-04 14:52:15.545: E/AndroidRuntime(369): FATAL EXCEPTION: main
04-04 14:52:15.545: E/AndroidRuntime(369): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.passstrings/com.example.passstrings.MainActivity}: java.lang.NullPointerException
04-04 14:52:15.545: E/AndroidRuntime(369): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
04-04 14:52:15.545: E/AndroidRuntime(369): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
04-04 14:52:15.545: E/AndroidRuntime(369): at android.app.ActivityThread.access$2300(ActivityThread.java:125)
04-04 14:52:15.545: E/AndroidRuntime(369): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
04-04 14:52:15.545: E/AndroidRuntime(369): at android.os.Handler.dispatchMessage(Handler.java:99)
04-04 14:52:15.545: E/AndroidRuntime(369): at android.os.Looper.loop(Looper.java:123)
04-04 14:52:15.545: E/AndroidRuntime(369): at android.app.ActivityThread.main(ActivityThread.java:4627)
04-04 14:52:15.545: E/AndroidRuntime(369): at java.lang.reflect.Method.invokeNative(Native Method)
04-04 14:52:15.545: E/AndroidRuntime(369): at java.lang.reflect.Method.invoke(Method.java:521)
04-04 14:52:15.545: E/AndroidRuntime(369): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
04-04 14:52:15.545: E/AndroidRuntime(369): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
04-04 14:52:15.545: E/AndroidRuntime(369): at dalvik.system.NativeStart.main(Native Method)
04-04 14:52:15.545: E/AndroidRuntime(369): Caused by: java.lang.NullPointerException
04-04 14:52:15.545: E/AndroidRuntime(369): at com.example.passstrings.MainActivity.onCreate(MainActivity.java:26)
04-04 14:52:15.545: E/AndroidRuntime(369): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
04-04 14:52:15.545: E/AndroidRuntime(369): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
04-04 14:52:15.545: E/AndroidRuntime(369): ... 11 more
4)abc.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin">
<TextView
android:id="@+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="23dp"
android:text="Which of the following vitamins helps clotting the blood : "
android:textSize="30sp" />
<RadioButton
android:id="@+id/radioButton1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/textView2"
android:layout_below="@+id/textView2"
android:layout_marginLeft="62dp"
android:layout_marginTop="14dp"
android:text="Vitamin A" />
<RadioButton
android:id="@+id/RadioButton03"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/RadioButton01"
android:layout_alignParentBottom="true"
android:layout_marginBottom="60dp"
android:text="None Of Above" />
<RadioButton
android:id="@+id/RadioButton01"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_above="@+id/RadioButton03"
android:layout_alignRight="@+id/RadioButton02"
android:layout_marginBottom="26dp"
android:text="Vitamin C" />
<RadioButton
android:id="@+id/RadioButton02"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/radioButton1"
android:layout_below="@+id/radioButton1"
android:layout_marginTop="16dp"
android:text="Vitamin D" />
<Button
android:id="@+id/button1"
style="?android:attr/buttonStyleSmall"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:text="Check"
android:textSize="30sp" />
</RelativeLayout>
5)fragment_main.xml:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.ytdownload.MainActivity$PlaceholderFragment" >
>
<TextView
android:id="@+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="23dp"
android:text="Click Below to start the test . Please only choose on of the answers"
android:textSize="30sp" />
<Button
android:id="@+id/button1"
style="?android:attr/buttonStyleSmall"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/textView2"
android:layout_centerHorizontal="true"
android:layout_marginTop="74dp"
android:text="Start"
android:textSize="30sp" />
</RelativeLayout>
6) list :
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.passstrings"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="19" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.passstrings.MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name="com.example.passstrings.abc" />
</application>
</manifest>
7)activity_main.xml:
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:ignore="MergeRootFrame"
tools:context="com.example.passstrings.MainActivity$PlaceholderFragment" >
>
</FrameLayout>
如果我将MainActivity中的setContentView更改为fragment，它会在LogCat中显示此错误“尽管将其设置为activity_main并编辑fragment_main总是对我有用”
04-04 15:13:42.995: I/dalvikvm(592): Could not find method android.content.pm.PackageManager.getActivityLogo, referenced from method android.support.v7.internal.widget.ActionBarView.<init>
04-04 15:13:42.995: W/dalvikvm(592): VFY: unable to resolve virtual method 320: Landroid/content/pm/PackageManager;.getActivityLogo (Landroid/content/ComponentName;)Landroid/graphics/drawable/Drawable;
04-04 15:13:42.995: D/dalvikvm(592): VFY: replacing opcode 0x6e at 0x008b
04-04 15:13:42.995: I/dalvikvm(592): Could not find method android.content.pm.ApplicationInfo.loadLogo, referenced from method android.support.v7.internal.widget.ActionBarView.<init>
04-04 15:13:42.995: W/dalvikvm(592): VFY: unable to resolve virtual method 316: Landroid/content/pm/ApplicationInfo;.loadLogo (Landroid/content/pm/PackageManager;)Landroid/graphics/drawable/Drawable;
04-04 15:13:42.995: D/dalvikvm(592): VFY: replacing opcode 0x6e at 0x0099
04-04 15:13:43.006: D/dalvikvm(592): VFY: dead code 0x008e-0092 in Landroid/support/v7/internal/widget/ActionBarView;.<init> (Landroid/content/Context;Landroid/util/AttributeSet;)V
04-04 15:13:43.006: D/dalvikvm(592): VFY: dead code 0x009c-00a0 in Landroid/support/v7/internal/widget/ActionBarView;.<init> (Landroid/content/Context;Landroid/util/AttributeSet;)V
04-04 15:13:43.135: E/FragmentManager(592): No view found for id 0x7f050042 (com.example.passstrings:id/container) for fragment PlaceholderFragment{4a310490 #0 id=0x7f050042}
04-04 15:13:43.135: E/FragmentManager(592): Activity state:
04-04 15:13:43.135: D/FragmentManager(592): Local FragmentActivity 4a2f4ae8 State:
04-04 15:13:43.135: D/FragmentManager(592): mCreated=truemResumed=false mStopped=false mReallyStopped=false
04-04 15:13:43.135: D/FragmentManager(592): mLoadersStarted=false
04-04 15:13:43.135: D/FragmentManager(592): Active Fragments in 4a2f5aa8:
04-04 15:13:43.135: D/FragmentManager(592): #0: PlaceholderFragment{4a310490 #0 id=0x7f050042}
04-04 15:13:43.151: D/FragmentManager(592): mFragmentId=#7f050042 mContainerId=#7f050042 mTag=null
04-04 15:13:43.151: D/FragmentManager(592): mState=0 mIndex=0 mWho=android:fragment:0 mBackStackNesting=0
04-04 15:13:43.155: D/FragmentManager(592): mAdded=true mRemoving=false mResumed=false mFromLayout=false mInLayout=false
04-04 15:13:43.155: D/FragmentManager(592): mHidden=false mDetached=false mMenuVisible=true mHasMenu=false
04-04 15:13:43.155: D/FragmentManager(592): mRetainInstance=false mRetaining=false mUserVisibleHint=true
04-04 15:13:43.155: D/FragmentManager(592): mFragmentManager=FragmentManager{4a2f5aa8 in MainActivity{4a2f4ae8}}
04-04 15:13:43.155: D/FragmentManager(592): mActivity=com.example.passstrings.MainActivity@4a2f4ae8
04-04 15:13:43.155: D/FragmentManager(592): Added Fragments:
04-04 15:13:43.165: D/FragmentManager(592): #0: PlaceholderFragment{4a310490 #0 id=0x7f050042}
04-04 15:13:43.165: D/FragmentManager(592): FragmentManager misc state:
04-04 15:13:43.165: D/FragmentManager(592): mActivity=com.example.passstrings.MainActivity@4a2f4ae8
04-04 15:13:43.165: D/FragmentManager(592): mContainer=android.support.v4.app.FragmentActivity$2@4a2f63b0
04-04 15:13:43.165: D/FragmentManager(592): mCurState=2 mStateSaved=false mDestroyed=false
04-04 15:13:43.165: D/FragmentManager(592): View Hierarchy:
04-04 15:13:43.165: D/FragmentManager(592): com.android.internal.policy.impl.PhoneWindow$DecorView{4a2f9690 V.E..... ... 0,0-0,0}
04-04 15:13:43.175: D/FragmentManager(592): android.widget.FrameLayout{4a2f9fd0 V.ED.... ... 0,0-0,0}
04-04 15:13:43.175: D/FragmentManager(592): android.widget.LinearLayout{4a2facf0 V.E..... ... 0,0-0,0}
04-04 15:13:43.175: D/FragmentManager(592): android.support.v7.internal.widget.ActionBarContainer{4a2fb788 V.ED.... ... 0,0-0,0 #7f050021 app:id/action_bar_container}
04-04 15:13:43.175: D/FragmentManager(592): android.support.v7.internal.widget.ActionBarView{4a304150 V.E..... ... 0,0-0,0 #7f050022 app:id/action_bar}
04-04 15:13:43.175: D/FragmentManager(592): android.widget.LinearLayout{4a308a98 G.....C. ... 0,0-0,0}
04-04 15:13:43.175: D/FragmentManager(592): android.widget.ImageView{4a3093e8 G.ED.... ... 0,0-0,0 #7f050027 app:id/up}
04-04 15:13:43.175: D/FragmentManager(592): android.widget.LinearLayout{4a309618 V.E..... ... 0,0-0,0}
04-04 15:13:43.187: D/FragmentManager(592): android.widget.TextView{4a309a98 V.ED.... ... 0,0-0,0 #7f050028 app:id/action_bar_title}
04-04 15:13:43.187: D/FragmentManager(592): android.widget.TextView{4a30acd8 G.ED.... ... 0,0-0,0 #7f050029 app:id/action_bar_subtitle}
04-04 15:13:43.187: D/FragmentManager(592): android.support.v7.internal.widget.ActionBarView$HomeView{4a305088 VFE...C. ... 0,0-0,0}
04-04 15:13:43.187: D/FragmentManager(592): android.widget.ImageView{4a307388 G.ED.... ... 0,0-0,0 #7f050027 app:id/up}
04-04 15:13:43.187: D/FragmentManager(592): android.widget.ImageView{4a3078e8 V.ED.... ... 0,0-0,0 #7f050014 app:id/home}
04-04 15:13:43.198: D/FragmentManager(592): android.support.v7.internal.widget.ActionBarContextView{4a30b6a8 G.E..... ... 0,0-0,0 #7f050023 app:id/action_context_bar}
04-04 15:13:43.198: D/FragmentManager(592): android.widget.FrameLayout{4a30c040 V.ED.... ... 0,0-0,0 #1020002 android:id/content}
04-04 15:13:43.198: D/FragmentManager(592): android.widget.RelativeLayout{4a30d688 V.E..... ... 0,0-0,0}
04-04 15:13:43.205: D/FragmentManager(592): android.widget.TextView{4a30db18 V.ED.... ... 0,0-0,0 #7f05001a app:id/textView2}
04-04 15:13:43.205: D/FragmentManager(592): android.widget.Button{4a30e368 VFED..C. ... 0,0-0,0 #7f05001f app:id/button1}
04-04 15:13:43.205: D/FragmentManager(592): android.support.v7.internal.widget.ActionBarContainer{4a30c2e8 G.ED.... ... 0,0-0,0 #7f050024 app:id/split_action_bar}
04-04 15:13:43.205: D/AndroidRuntime(592): Shutting down VM
04-04 15:13:43.205: W/dalvikvm(592): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
04-04 15:13:43.215: E/AndroidRuntime(592): FATAL EXCEPTION: main
04-04 15:13:43.215: E/AndroidRuntime(592): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.passstrings/com.example.passstrings.MainActivity}: java.lang.IllegalArgumentException: No view found for id 0x7f050042 (com.example.passstrings:id/container) for fragment PlaceholderFragment{4a310490 #0 id=0x7f050042}
04-04 15:13:43.215: E/AndroidRuntime(592): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
04-04 15:13:43.215: E/AndroidRuntime(592): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
04-04 15:13:43.215: E/AndroidRuntime(592): at android.app.ActivityThread.access$2300(ActivityThread.java:125)
04-04 15:13:43.215: E/AndroidRuntime(592): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
04-04 15:13:43.215: E/AndroidRuntime(592): at android.os.Handler.dispatchMessage(Handler.java:99)
04-04 15:13:43.215: E/AndroidRuntime(592): at android.os.Looper.loop(Looper.java:123)
04-04 15:13:43.215: E/AndroidRuntime(592): at android.app.ActivityThread.main(ActivityThread.java:4627)
04-04 15:13:43.215: E/AndroidRuntime(592): at java.lang.reflect.Method.invokeNative(Native Method)
04-04 15:13:43.215: E/AndroidRuntime(592): at java.lang.reflect.Method.invoke(Method.java:521)
04-04 15:13:43.215: E/AndroidRuntime(592): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
04-04 15:13:43.215: E/AndroidRuntime(592): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
04-04 15:13:43.215: E/AndroidRuntime(592): at dalvik.system.NativeStart.main(Native Method)
04-04 15:13:43.215: E/AndroidRuntime(592): Caused by: java.lang.IllegalArgumentException: No view found for id 0x7f050042 (com.example.passstrings:id/container) for fragment PlaceholderFragment{4a310490 #0 id=0x7f050042}
04-04 15:13:43.215: E/AndroidRuntime(592): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:930)
04-04 15:13:43.215: E/AndroidRuntime(592): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1115)
04-04 15:13:43.215: E/AndroidRuntime(592): at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:682)
04-04 15:13:43.215: E/AndroidRuntime(592): at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1478)
04-04 15:13:43.215: E/AndroidRuntime(592): at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:570)
04-04 15:13:43.215: E/AndroidRuntime(592): at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1129)
04-04 15:13:43.215: E/AndroidRuntime(592): at android.app.Activity.performStart(Activity.java:3781)
04-04 15:13:43.215: E/AndroidRuntime(592): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2636)
04-04 15:13:43.215: E/AndroidRuntime(592): ... 11 more
最佳答案
NullPointerException是因为您试图在activity_main.xml中查找R.id.textView2和R.id.button1，而这些 ID 不存在。
如果您仔细查看日志，会有一行指出 NPE 发生的位置，在您的情况下是这一行:
04-04 14:52:15.545: E/AndroidRuntime(369): Caused by: java.lang.NullPointerException
04-04 14:52:15.545: E/AndroidRuntime(369): at com.example.passstrings.MainActivity.onCreate(MainActivity.java:26)
正如您所看到的，在类 MainActivity.java 的第 26 行中，特别是在 onCreate() 方法中，发生了错误，我我几乎可以肯定该错误是由 xml 中缺少 id 引起的。要解决此问题，您必须将 Button 和 TextView 放入 main_activity.xml 中，并使用代码中指定的 id (R.id.textView2和R.id.button1)
关于java - 使用 startActivityForResult 时应用程序崩溃，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/22866329/