Android 应用程序在按钮单击时崩溃

Question

您好，我编写了一个带有两个 xml 页面的简单 android 应用程序，其中一个有一个图像按钮，我将其设置为在单击时打开第二个 xml 页面。该代码没有返回错误并且运行良好，但是当我单击 android 模拟器中的按钮时，它崩溃并要求我强制关闭。这是我正在处理的代码：

第一个活动：

package com.android.Train;

import com.android.TrainMenu.MenuActivity;

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

    public class TrainActivity extends Activity 
    {
        /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
    }

    public void goMenu(View v)
    {
      Intent myIntent = new Intent(this, MenuActivity.class);
      startActivity(myIntent);
    }    
}

第一个 XML 文件：

 <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <ImageButton
        android:id="@+id/enterButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/button_enter"
        android:clickable="true"
        android:onClick="goMenu" />

    </LinearLayout>

第二个活动：

package com.android.TrainMenu;

import android.app.Activity;
import android.os.Bundle;

import com.android.Train.R;

public class MenuActivity extends Activity 
{
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.menu);
    }
}

第二个 XML 文件：

 <?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >

</RelativeLayout>

关于为什么会崩溃的任何想法？

预先感谢

我刚刚再次运行它，这是 logCat 文件

01-26 14:21:37.784: D/AndroidRuntime(287): Shutting down VM
01-26 14:21:37.784: W/dalvikvm(287): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
01-26 14:21:37.815: E/AndroidRuntime(287): FATAL EXCEPTION: main
01-26 14:21:37.815: E/AndroidRuntime(287): java.lang.IllegalStateException: Could not execute method of the activity
01-26 14:21:37.815: E/AndroidRuntime(287):  at android.view.View$1.onClick(View.java:2072)
01-26 14:21:37.815: E/AndroidRuntime(287):  at android.view.View.performClick(View.java:2408)
01-26 14:21:37.815: E/AndroidRuntime(287):  at android.view.View$PerformClick.run(View.java:8816)
01-26 14:21:37.815: E/AndroidRuntime(287):  at android.os.Handler.handleCallback(Handler.java:587)
01-26 14:21:37.815: E/AndroidRuntime(287):  at android.os.Handler.dispatchMessage(Handler.java:92)
01-26 14:21:37.815: E/AndroidRuntime(287):  at android.os.Looper.loop(Looper.java:123)
01-26 14:21:37.815: E/AndroidRuntime(287):  at android.app.ActivityThread.main(ActivityThread.java:4627)
01-26 14:21:37.815: E/AndroidRuntime(287):  at java.lang.reflect.Method.invokeNative(Native Method)
01-26 14:21:37.815: E/AndroidRuntime(287):  at java.lang.reflect.Method.invoke(Method.java:521)
01-26 14:21:37.815: E/AndroidRuntime(287):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
01-26 14:21:37.815: E/AndroidRuntime(287):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
01-26 14:21:37.815: E/AndroidRuntime(287):  at dalvik.system.NativeStart.main(Native Method)
01-26 14:21:37.815: E/AndroidRuntime(287): Caused by: java.lang.reflect.InvocationTargetException
01-26 14:21:37.815: E/AndroidRuntime(287):  at com.android.Train.TrainActivity.goMenu(TrainActivity.java:23)
01-26 14:21:37.815: E/AndroidRuntime(287):  at java.lang.reflect.Method.invokeNative(Native Method)
01-26 14:21:37.815: E/AndroidRuntime(287):  at java.lang.reflect.Method.invoke(Method.java:521)
01-26 14:21:37.815: E/AndroidRuntime(287):  at android.view.View$1.onClick(View.java:2067)
01-26 14:21:37.815: E/AndroidRuntime(287):  ... 11 more
01-26 14:21:37.815: E/AndroidRuntime(287): Caused by: android.content.ActivityNotFoundException: Unable to find explicit activity class {com.android.Train/com.android.TrainMenu.MenuActivity}; have you declared this activity in your AndroidManifest.xml?
01-26 14:21:37.815: E/AndroidRuntime(287):  at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:1404)
01-26 14:21:37.815: E/AndroidRuntime(287):  at android.app.Instrumentation.execStartActivity(Instrumentation.java:1378)
01-26 14:21:37.815: E/AndroidRuntime(287):  at android.app.Activity.startActivityForResult(Activity.java:2817)
01-26 14:21:37.815: E/AndroidRuntime(287):  at android.app.Activity.startActivity(Activity.java:2923)
01-26 14:21:37.815: E/AndroidRuntime(287):  ... 15 more

Android Manifest.XML

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.android.Train"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk android:minSdkVersion="7" />

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name" >
        <activity
            android:label="@string/app_name"
            android:name=".TrainActivity" >
            <intent-filter >
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <activity
        android:name=".MenuActivity"
        android:label="@string/app_name" />

    </application>

</manifest>

Answer 1

我认为这是因为您的 MenuActivity 类与您的 TrainActivity 类位于不同的包中。我不确定如何使用您拥有的包布局来做到这一点，但如果您有以下内容：

com.ardroid.train.TrainActivity
com.ardroid.train.menu.MenuActivity

那么您的清单条目将是：

<activity 
    android:name=".menu.MenuActivity "
    android:label="@string/app_name" />

Answer 2

我认为您尚未在清单文件中输入活动
每个活动必须存在于 AndroidManifest.xml 文件中
像这样

   <application  
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name" >
    <activity 
        android:name=".TrainActivity "
        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=".MenuActivity "
        android:label="@string/app_name" />
</application>

如果有问题然后使用
Intent myIntent = new Intent(TrainActivity.this, MenuActivity.class);

Answer 3

您需要在 Activty 上实例化 ImageButtom：

ImageButton btnImg;

... oncreadte(...) {

btnImg = (ImageButton) findViewById(R.id.enterButton);

...

btnImg.setOnClickListener(new OnClickListener() {

            public void onClick(View v) {

// This call new Activity on press ImageButton
Intent it = new Intent(TrainActivity.this, MenuActivity.class);
startActivity(it);

}

}

祝您好运。

Answer 4

首先，您需要将活动添加到清单文件中（没有空格）：

<activity android:name=".MenuActivity"></activity>

其次，对于按钮本身，这是有关如何完成此操作的建议：

import com.android.TrainMenu.MenuActivity;

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

    public class TrainActivity extends Activity 
    {

    ImageButton button;

    @Override
    public void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        button = (ImageButton) findViewById(R.id.enterButton);

        button.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View arg0) {
                   goMenu();
            }

        });
    }


    public void goMenu()
    {
      Intent myIntent = new Intent(this, MenuActivity.class);
      startActivity(myIntent);
    }    
}

Answer 5

确保将这两个活动添加到 AndroidManifest.xml 文件中。

Answer 6

我认为你有不同包中的课程。