Java 在MainActivity和FirstChildActivity之间插入NewChildDaActivity，并将默认ChildActivity更改为NewChildActivity

各位朋友:

谢谢大家一如既往的支持

我开发了一个具有登录功能的考试应用程序

以前，该应用程序有3个活动（MainActivity、WelcomeScreenActivity和QuestionsActivity）。这个应用程序运行得很好

但是，当用户从MainActivity登录时，将显示WelcomeScreenActivity。 但是我需要在main活动和WelcomeScreenActivity之间插入另一个活动（PROFILE_活动），这样，当用户成功登录时，应用程序将显示用户的PROFILEACTIVITY

页面下方的图片

新档案活动之前的上一个代码 MainActivity.java代码

@Override
        protected void onPostExecute(Void result){
            if (!responseData.equals( "User Not Found" )) {
                message = "Welcome";
                data = responseData;//store the user id from the server in data
                //Bundle bundle = new Bundle();//bundle the message and parse it to the next activity
                //bundle.putString("dispMsg", message);//bundle the message using the variable dispMsg
                //intent.putExtras(bundle);
                startActivity(intent);
                statusBar.setText(message);
            } else {
                message = responseData;//"Incorrect Username or Password. Try again!";
                statusBar.setText(message);
            }
            super.onPostExecute(result);
        }

?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.examinationportal">

    <uses-permission
        android:name="android.permission.INTERNET"
        android:required="true" />
    <uses-permission
        android:name="android.permission.ACCESS_NETWORK_STATE"
        android:required="true" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.AppCompat.DayNight.DarkActionBar">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <activity android:name=".DisplayWelcomeScreen"
            android:label="@string/welcome_screen_title"
            android:parentActivityName=".MainActivity">

            <!-- The meta-data tag is required if you support API level 15 and lower -->
            <meta-data
                android:name="android.support.PARENT_ACTIVITY"
                android:value=".MainActivity" />

        </activity>

        <activity
            android:name=".CSS_342_Questions"
            android:allowTaskReparenting="true"
            android:label="@string/question_screen"
            android:parentActivityName=".DisplayWelcomeScreen">

            <!-- The meta-data tag is required if you support API level 15 and lower -->
            <meta-data
                android:name="android.support.PARENT_ACTIVITY"
                android:value=".DisplayWelcomeScreen" />
        </activity>
        <activity
            android:name=".RegisterUserActivity"
            android:label="@string/new_user_form"
            android:parentActivityName=".MainActivity">

            <!-- The meta-data tag is required if you support API level 15 and lower -->
            <meta-data
                android:name="android.support.PARENT_ACTIVITY"
                android:value=".MainActivity" />
        </activity>
    </application>

</manifest>

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.examinationportal">

    <uses-permission
        android:name="android.permission.INTERNET"
        android:required="true" />
    <uses-permission
        android:name="android.permission.ACCESS_NETWORK_STATE"
        android:required="true" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.AppCompat.DayNight.DarkActionBar">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <activity android:name=".ProfileAcvitity"
            android:label="@string/student_profile"
            android:parentActivityName=".MainActivity">

            <!-- The meta-data tag is required if you support API level 15 and lower -->
            <meta-data
                android:name="android.support.PARENT_ACTIVITY"
                android:value=".MainActivity" />

        </activity>

        <activity
            android:name=".RegisterUserActivity"
            android:label="@string/new_user_form"
            android:parentActivityName=".MainActivity">

            <!-- The meta-data tag is required if you support API level 15 and lower -->
            <meta-data
                android:name="android.support.PARENT_ACTIVITY"
                android:value=".MainActivity" />
        </activity>
    </application>

</manifest>

public class ProfileAcvitity extends AppCompatActivity {
    public Intent intent;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_profile_acvitity);

        intent = getIntent();
    }

DisplayWelcomeScreenActivity.java代码 此活动在成功登录后显示

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_display_welcome_screen);

    // Get the Intent that started this activity and extract the string
        intent = getIntent();
}

要将此WelcomeActivity传递到下一个QuestionsActivity，下面的代码将在buttonclick（）事件上执行此操作

使用下面的代码显示QuestionsActivity

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_css_342__questions);

        // Get the Intent that started this activity and extract the string
        intent = getIntent();
        bundle = getIntent().getExtras();

        showCode = bundle.getString("dispCode");
        qNum = bundle.getInt("qNum");
}

下面的代码是清单xml，它将3个活动链接在一起以实现正确的导航

AndroidManifest.XML代码

@Override
        protected void onPostExecute(Void result){
            if (!responseData.equals( "User Not Found" )) {
                message = "Welcome";
                data = responseData;//store the user id from the server in data
                //Bundle bundle = new Bundle();//bundle the message and parse it to the next activity
                //bundle.putString("dispMsg", message);//bundle the message using the variable dispMsg
                //intent.putExtras(bundle);
                startActivity(intent);
                statusBar.setText(message);
            } else {
                message = responseData;//"Incorrect Username or Password. Try again!";
                statusBar.setText(message);
            }
            super.onPostExecute(result);
        }

?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.examinationportal">

    <uses-permission
        android:name="android.permission.INTERNET"
        android:required="true" />
    <uses-permission
        android:name="android.permission.ACCESS_NETWORK_STATE"
        android:required="true" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.AppCompat.DayNight.DarkActionBar">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <activity android:name=".DisplayWelcomeScreen"
            android:label="@string/welcome_screen_title"
            android:parentActivityName=".MainActivity">

            <!-- The meta-data tag is required if you support API level 15 and lower -->
            <meta-data
                android:name="android.support.PARENT_ACTIVITY"
                android:value=".MainActivity" />

        </activity>

        <activity
            android:name=".CSS_342_Questions"
            android:allowTaskReparenting="true"
            android:label="@string/question_screen"
            android:parentActivityName=".DisplayWelcomeScreen">

            <!-- The meta-data tag is required if you support API level 15 and lower -->
            <meta-data
                android:name="android.support.PARENT_ACTIVITY"
                android:value=".DisplayWelcomeScreen" />
        </activity>
        <activity
            android:name=".RegisterUserActivity"
            android:label="@string/new_user_form"
            android:parentActivityName=".MainActivity">

            <!-- The meta-data tag is required if you support API level 15 and lower -->
            <meta-data
                android:name="android.support.PARENT_ACTIVITY"
                android:value=".MainActivity" />
        </activity>
    </application>

</manifest>

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.examinationportal">

    <uses-permission
        android:name="android.permission.INTERNET"
        android:required="true" />
    <uses-permission
        android:name="android.permission.ACCESS_NETWORK_STATE"
        android:required="true" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.AppCompat.DayNight.DarkActionBar">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <activity android:name=".ProfileAcvitity"
            android:label="@string/student_profile"
            android:parentActivityName=".MainActivity">

            <!-- The meta-data tag is required if you support API level 15 and lower -->
            <meta-data
                android:name="android.support.PARENT_ACTIVITY"
                android:value=".MainActivity" />

        </activity>

        <activity
            android:name=".RegisterUserActivity"
            android:label="@string/new_user_form"
            android:parentActivityName=".MainActivity">

            <!-- The meta-data tag is required if you support API level 15 and lower -->
            <meta-data
                android:name="android.support.PARENT_ACTIVITY"
                android:value=".MainActivity" />
        </activity>
    </application>

</manifest>

public class ProfileAcvitity extends AppCompatActivity {
    public Intent intent;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_profile_acvitity);

        intent = getIntent();
    }

新建ProfileActivity.java代码

@Override
        protected void onPostExecute(Void result){
            if (!responseData.equals( "User Not Found" )) {
                message = "Welcome";
                data = responseData;//store the user id from the server in data
                //Bundle bundle = new Bundle();//bundle the message and parse it to the next activity
                //bundle.putString("dispMsg", message);//bundle the message using the variable dispMsg
                //intent.putExtras(bundle);
                startActivity(intent);
                statusBar.setText(message);
            } else {
                message = responseData;//"Incorrect Username or Password. Try again!";
                statusBar.setText(message);
            }
            super.onPostExecute(result);
        }

?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.examinationportal">

    <uses-permission
        android:name="android.permission.INTERNET"
        android:required="true" />
    <uses-permission
        android:name="android.permission.ACCESS_NETWORK_STATE"
        android:required="true" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.AppCompat.DayNight.DarkActionBar">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <activity android:name=".DisplayWelcomeScreen"
            android:label="@string/welcome_screen_title"
            android:parentActivityName=".MainActivity">

            <!-- The meta-data tag is required if you support API level 15 and lower -->
            <meta-data
                android:name="android.support.PARENT_ACTIVITY"
                android:value=".MainActivity" />

        </activity>

        <activity
            android:name=".CSS_342_Questions"
            android:allowTaskReparenting="true"
            android:label="@string/question_screen"
            android:parentActivityName=".DisplayWelcomeScreen">

            <!-- The meta-data tag is required if you support API level 15 and lower -->
            <meta-data
                android:name="android.support.PARENT_ACTIVITY"
                android:value=".DisplayWelcomeScreen" />
        </activity>
        <activity
            android:name=".RegisterUserActivity"
            android:label="@string/new_user_form"
            android:parentActivityName=".MainActivity">

            <!-- The meta-data tag is required if you support API level 15 and lower -->
            <meta-data
                android:name="android.support.PARENT_ACTIVITY"
                android:value=".MainActivity" />
        </activity>
    </application>

</manifest>

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.examinationportal">

    <uses-permission
        android:name="android.permission.INTERNET"
        android:required="true" />
    <uses-permission
        android:name="android.permission.ACCESS_NETWORK_STATE"
        android:required="true" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.AppCompat.DayNight.DarkActionBar">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <activity android:name=".ProfileAcvitity"
            android:label="@string/student_profile"
            android:parentActivityName=".MainActivity">

            <!-- The meta-data tag is required if you support API level 15 and lower -->
            <meta-data
                android:name="android.support.PARENT_ACTIVITY"
                android:value=".MainActivity" />

        </activity>

        <activity
            android:name=".RegisterUserActivity"
            android:label="@string/new_user_form"
            android:parentActivityName=".MainActivity">

            <!-- The meta-data tag is required if you support API level 15 and lower -->
            <meta-data
                android:name="android.support.PARENT_ACTIVITY"
                android:value=".MainActivity" />
        </activity>
    </application>

</manifest>

public class ProfileAcvitity extends AppCompatActivity {
    public Intent intent;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_profile_acvitity);

        intent = getIntent();
    }

日志信息 请帮我解决这个问题

多谢各位

---

在您的

AndroidManifest.xml

文件中添加这些行将解决您的问题。

显然是说

DisplayWelcomeScreen

未在清单文件中定义。因此，请在清单中定义

DisplayWelcomeScreen

Activity。酋长，在你获得logcat信息之前，你还没有完全阅读我的帖子。我说我正在DisplayWelcomeActivity之前插入一个新活动。这就是为什么我删除了DisplayWelcomeActivity并改为放置ProfileActivity，这会引发一个崩溃错误。亲爱的朋友，我说我正在DisplayWelcomeActivity之前插入一个新活动。这就是为什么我删除了DisplayWelcomeActivity并改为放置ProfileActivity，它现在抛出了一个崩溃错误。您在上面放置的代码将只移动到DisplayWelcomeActivity而不是ProfileActivity。这不是我想展示的活动。