有一个简单的类,当我尝试进行ColgarAWalter活动时,我的应用程序因致命异常而崩溃。我看到了其他用户的一些解决方案并进行了一些修改。我应该对XML中的onClickListener进行调用,因为我觉得它对我来说更舒适,不需要在主类上编写太多代码]
主要活动在主要活动上,我进入了Intent vista.getContext(),但我认为两者都相同
package com.example.practica_4_walter_white;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void llamando(View vista){
Intent intent=new Intent(MainActivity.this,ColgarAWalter.class);
startActivity(intent);
}
}
COLGAR A WALTER
package com.example.practica_4_walter_white;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import androidx.appcompat.app.AppCompatActivity;
public class ColgarAWalter extends AppCompatActivity {
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.llamando_al_peligro);
}
public void colgar(View vista){
Intent intent=new Intent(ColgarAWalter.this,MainActivity.class);
startActivity(intent);
}
}
activity_main.XML
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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:layout_height="match_parent"
tools:context=".MainActivity">
<TextView
android:id="@+id/encabezado"
android:layout_width="207dp"
android:layout_height="47dp"
android:text="Puedes llamar a walter white"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.096" />
<ImageView
android:id="@+id/walter"
android:layout_width="213dp"
android:layout_height="211dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.498"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.779"
app:srcCompat="@drawable/walterwhite" />
<ImageButton
android:src="@drawable/llamar"
android:layout_width="106dp"
android:layout_height="116dp"
android:onClick="llamando"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.498"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.265"
app:srcCompat="@drawable/llamar" />
</androidx.constraintlayout.widget.ConstraintLayout>
在XML上,我有+ id来引用ImageButton,但是我看到有人说它最好放在src和@ drawable / llamar或类似的名称中llamando_al_peligro.XML
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
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:layout_height="match_parent"
tools:context=".ColgarAWalter">
<ImageView
android:id="@+id/walter_2"
android:layout_width="207dp"
android:layout_height="192dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.801"
app:srcCompat="@drawable/walterwhite2" />
<ImageButton
android:src="@drawable/colgar"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="220dp"
android:onClick="colgar"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.498"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.0"
app:srcCompat="@drawable/colgar" />
<TextView
android:id="@+id/encabezado2"
android:layout_width="322dp"
android:layout_height="84dp"
android:text="Calling the Danger Skyler..."
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.494"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.072" />
</androidx.constraintlayout.widget.ConstraintLayout>
DEBBUGING EROOR
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.practica_4_walter_white, PID: 9015
java.lang.IllegalStateException: Could not execute method for android:onClick
at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:390)
at android.view.View.performClick(View.java:6608)
at android.view.View.performClickInternal(View.java:6585)
at android.view.View.access$3100(View.java:785)
at android.view.View$PerformClick.run(View.java:25921)
at android.os.Handler.handleCallback(Handler.java:873)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:201)
at android.app.ActivityThread.main(ActivityThread.java:6861)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:547)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:873)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invoke(Native Method)
at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:385)
at android.view.View.performClick(View.java:6608)
at android.view.View.performClickInternal(View.java:6585)
at android.view.View.access$3100(View.java:785)
at android.view.View$PerformClick.run(View.java:25921)
at android.os.Handler.handleCallback(Handler.java:873)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:201)
at android.app.ActivityThread.main(ActivityThread.java:6861)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:547)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:873)
Caused by: android.content.ActivityNotFoundException: Unable to find explicit activity class {com.example.practica_4_walter_white/com.example.practica_4_walter_white.ColgarAWalter}; have you declared this activity in your AndroidManifest.xml?
at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:2014)
at android.app.Instrumentation.execStartActivity(Instrumentation.java:1677)
at android.app.Activity.startActivityForResult(Activity.java:4651)
at androidx.fragment.app.FragmentActivity.startActivityForResult(FragmentActivity.java:767)
at android.app.Activity.startActivityForResult(Activity.java:4609)
at androidx.fragment.app.FragmentActivity.startActivityForResult(FragmentActivity.java:754)
at android.app.Activity.startActivity(Activity.java:4970)
at android.app.Activity.startActivity(Activity.java:4938)
at com.example.practica_4_walter_white.MainActivity.llamando(MainActivity.java:19)
at java.lang.reflect.Method.invoke(Native Method)
at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:385)
at android.view.View.performClick(View.java:6608)
at android.view.View.performClickInternal(View.java:6585)
at android.view.View.access$3100(View.java:785)
at android.view.View$PerformClick.run(View.java:25921)
at android.os.Handler.handleCallback(Handler.java:873)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:201)
at android.app.ActivityThread.main(ActivityThread.java:6861)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:547)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:873)
我第一次将清单放在这里,我第一次知道清单存在,所以我不编辑任何内容
MANIFEST
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.practica_4_walter_white">
<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>
</application>
</manifest>
代表OP发布
就我而言,解决方案是我不编辑清单文件,因此系统无法识别我的第二项活动,因此可以正常工作。
<activity android:name=".ColgarAWalter"></activity>
我现在正确放置了所有清单代码
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.practica_4_walter_white">
<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=".ColgarAWalter"></activity>
</application>
</manifest>