java - 将“设置” Activity 连接到“Activity 2”后，我的应用程序崩溃了

Question

因为我仍然是 Android Studio 的新手，所以我尝试使用 YouTube-Tutorial 将编码 Activity 连接到该 Activity (我上面有设置按钮的 Activity )。当我现在单击按钮时，我应该从设置 Activity 中获得常规设置。但我的应用程序崩溃了，并告诉我:不幸的是，应用程序停止了。

我不明白我做错了什么，我试了3次。我的意思是，根据教程，它必须非常简单。

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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:background="#F4F8C8"
    tools:context=".StartH" android:layout_height="match_parent">

    <TextView
        android:id="@+id/WelcomeH"
        android:layout_width="95dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="158dp"
        android:layout_marginTop="45dp"
        android:layout_marginEnd="157dp"
        android:layout_marginBottom="649dp"
        android:background="#B5651E"
        android:padding="7dp"
        android:text="@string/welcome_hunter"
        android:textAlignment="center"
        android:textColor="#FFEB3B"
        android:textSize="18sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <CalendarView
        android:id="@+id/calendarView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="35sp"
        android:layout_marginTop="150dp"
        tools:layout_editor_absoluteX="33dp"
        tools:layout_editor_absoluteY="143dp" />

    <Button
        android:id="@+id/button"
        android:layout_width="102dp"
        android:layout_height="48dp"
        android:layout_marginStart="150dp"
        android:layout_marginTop="500dp"
        android:background="#B5651E"
        android:text="@string/new_entry"
        tools:layout_editor_absoluteX="163dp"
        tools:layout_editor_absoluteY="532dp" />

    <Button
        android:id="@+id/btnSettings"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="btnSettings_onClick"
        android:text="@string/settings" />

    <Button
        android:id="@+id/btnRead"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="100dp"
        android:onClick="btnRead_onClick"
        android:text="@string/read_settings" />

</RelativeLayout>

(按钮位于 Activity 2 上而不是主 Activity 上)

主要 Activity :

    package com.goldenegg.hunterapp;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;

public class MainActivity extends Activity {


    private MenuItem item;

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

        public void btnSettings_onClick(View view) {
        Intent intent=new Intent (this, SettingsActivity.class);
        startActivity(intent);
    }

    }

    public void openHunter() {
        Intent intent = new Intent(this, Hunter.class);
        startActivity(intent);
    }

    public void openFisher() {
        Intent intent = new Intent(this, Fisher.class);
        startActivity(intent);

    }

根据教程，当我单击按钮时，它已经可以工作了。我做错了什么？

感谢帮助

这是日志猫

03-17 17:47:13.289 2915-2915/? E/libprocessgroup: failed to make and chown /acct/uid_10058: Read-only file system
03-17 17:47:13.290 2915-2915/? W/Zygote: createProcessGroup failed, kernel missing CONFIG_CGROUP_CPUACCT?
03-17 17:47:13.290 2915-2915/? I/art: Not late-enabling -Xcheck:jni (already on)
03-17 17:47:13.344 2915-2930/com.goldenegg.hunterapp D/OpenGLRenderer: Use EGL_SWAP_BEHAVIOR_PRESERVED: true
03-17 17:47:13.360 2915-2915/com.goldenegg.hunterapp D/Atlas: Validating map...
03-17 17:47:13.449 2915-2930/com.goldenegg.hunterapp I/OpenGLRenderer: Initialized EGL, version 1.4
03-17 17:47:13.449 2915-2930/com.goldenegg.hunterapp W/OpenGLRenderer: Failed to choose config with EGL_SWAP_BEHAVIOR_PRESERVED, retrying without...
03-17 17:47:13.462 2915-2930/com.goldenegg.hunterapp D/EGL_emulation: eglCreateContext: 0xb42a4ac0: maj 2 min 0 rcv 2
03-17 17:47:13.479 2915-2930/com.goldenegg.hunterapp D/EGL_emulation: eglMakeCurrent: 0xb42a4ac0: ver 2 0 (tinfo 0xb4272c70)
03-17 17:47:13.482 2915-2930/com.goldenegg.hunterapp D/OpenGLRenderer: Enabling debug mode 0
03-17 17:47:13.499 2915-2930/com.goldenegg.hunterapp D/EGL_emulation: eglMakeCurrent: 0xb42a4ac0: ver 2 0 (tinfo 0xb4272c70)
03-17 17:47:18.656 2915-2930/com.goldenegg.hunterapp D/EGL_emulation: eglMakeCurrent: 0xb42a4ac0: ver 2 0 (tinfo 0xb4272c70)
03-17 17:47:18.687 2915-2930/com.goldenegg.hunterapp D/EGL_emulation: eglMakeCurrent: 0xb42a4ac0: ver 2 0 (tinfo 0xb4272c70)
03-17 17:47:18.696 2915-2930/com.goldenegg.hunterapp D/EGL_emulation: eglMakeCurrent: 0xb42a4ac0: ver 2 0 (tinfo 0xb4272c70)
03-17 17:47:23.891 2915-2930/com.goldenegg.hunterapp D/EGL_emulation: eglMakeCurrent: 0xb42a4ac0: ver 2 0 (tinfo 0xb4272c70)
03-17 17:47:23.893 2915-2915/com.goldenegg.hunterapp I/Choreographer: Skipped 311 frames!  The application may be doing too much work on its main thread.
03-17 17:47:23.909 2915-2930/com.goldenegg.hunterapp D/EGL_emulation: eglMakeCurrent: 0xb42a4ac0: ver 2 0 (tinfo 0xb4272c70)
03-17 17:47:23.947 2915-2930/com.goldenegg.hunterapp D/EGL_emulation: eglMakeCurrent: 0xb42a4ac0: ver 2 0 (tinfo 0xb4272c70)
03-17 17:47:23.960 2915-2930/com.goldenegg.hunterapp D/EGL_emulation: eglMakeCurrent: 0xb42a4ac0: ver 2 0 (tinfo 0xb4272c70)
03-17 17:47:25.144 2915-2930/com.goldenegg.hunterapp D/EGL_emulation: eglMakeCurrent: 0xb42a4ac0: ver 2 0 (tinfo 0xb4272c70)
03-17 17:47:25.209 2915-2915/com.goldenegg.hunterapp D/AndroidRuntime: Shutting down VM
03-17 17:47:25.209 2915-2915/com.goldenegg.hunterapp E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.goldenegg.hunterapp, PID: 2915
    java.lang.IllegalStateException: Could not find a method btnSettings_onClick(View) in the activity class com.goldenegg.hunterapp.Hunter for onClick handler on view class android.widget.Button with id 'btnSettings'
        at android.view.View$1.onClick(View.java:4007)
        at android.view.View.performClick(View.java:4780)
        at android.view.View$PerformClick.run(View.java:19866)
        at android.os.Handler.handleCallback(Handler.java:739)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:135)
        at android.app.ActivityThread.main(ActivityThread.java:5254)
        at java.lang.reflect.Method.invoke(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:372)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
     Caused by: java.lang.NoSuchMethodException: btnSettings_onClick [class android.view.View]
        at java.lang.Class.getMethod(Class.java:664)
        at java.lang.Class.getMethod(Class.java:643)
        at android.view.View$1.onClick(View.java:4000)
        at android.view.View.performClick(View.java:4780) 
        at android.view.View$PerformClick.run(View.java:19866) 
        at android.os.Handler.handleCallback(Handler.java:739) 
        at android.os.Handler.dispatchMessage(Handler.java:95) 
        at android.os.Looper.loop(Looper.java:135) 
        at android.app.ActivityThread.main(ActivityThread.java:5254) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at java.lang.reflect.Method.invoke(Method.java:372) 
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698) 

Answer 1

public void btnSettings_onClick(View view) {
        Intent intent=new Intent (this, SettingsActivity.class);
        startActivity(intent);
    }

此函数不应位于 onCreate 主体中，请将其移出并重试。

编辑:

我做了一个简单的项目来向您展示它是如何完成的。请注意，在 AndroidManifest

中添加新 Activity (设置)非常重要

AndroidManifest.xml:

<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/AppTheme">
        <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=".SettingsActivity" />
    </application>

主要 Activity :

public class MainActivity extends AppCompatActivity {

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

    public void btnSettings_onClick(View view) {
        Intent intent=new Intent (this, SettingsActivity.class);
        startActivity(intent);
    }
}

设置 Activity :

public class SettingsActivity extends AppCompatActivity {

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

}

为了帮助您学习 Android，您应该看看:

• https://developer.android.com/courses/fundamentals-training/overview-v2
• Coding in Flow