Question

我有一个按钮，当点击它时我想加载一个新视图。

我正在使用这个主要活动类

public class MainActivity extends ActionBarActivity {

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

public void buttonPressed(View v){
    Intent i = new Intent(this, SwitchedActivity.class);
    startActivity(i);
}
}

然后我想加载其他活动

public class SwitchedActivity extends Activity {
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_two);
}
}

那么应该发生什么，是我单击activity_main.xml中的按钮，然后从activity_two.xml加载布局。

问题是，当我点击按钮时，应用程序就崩溃了。

我得到了这个logcat堆栈跟踪：

08-18 11:36:09.078: E/AndroidRuntime(1232): FATAL EXCEPTION: main
08-18 11:36:09.078: E/AndroidRuntime(1232): Process: com.johncorser.myapp, PID: 1232
08-18 11:36:09.078: E/AndroidRuntime(1232): java.lang.IllegalStateException: Could not execute method of the activity
08-18 11:36:09.078: E/AndroidRuntime(1232):     at android.view.View$1.onClick(View.java:3823)
08-18 11:36:09.078: E/AndroidRuntime(1232):     at android.view.View.performClick(View.java:4438)
08-18 11:36:09.078: E/AndroidRuntime(1232):     at android.view.View$PerformClick.run(View.java:18422)
08-18 11:36:09.078: E/AndroidRuntime(1232):     at android.os.Handler.handleCallback(Handler.java:733)
08-18 11:36:09.078: E/AndroidRuntime(1232):     at android.os.Handler.dispatchMessage(Handler.java:95)
08-18 11:36:09.078: E/AndroidRuntime(1232):     at android.os.Looper.loop(Looper.java:136)
08-18 11:36:09.078: E/AndroidRuntime(1232):     at android.app.ActivityThread.main(ActivityThread.java:5017)
08-18 11:36:09.078: E/AndroidRuntime(1232):     at java.lang.reflect.Method.invokeNative(Native Method)
08-18 11:36:09.078: E/AndroidRuntime(1232):     at java.lang.reflect.Method.invoke(Method.java:515)
08-18 11:36:09.078: E/AndroidRuntime(1232):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
08-18 11:36:09.078: E/AndroidRuntime(1232):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
08-18 11:36:09.078: E/AndroidRuntime(1232):     at dalvik.system.NativeStart.main(Native Method)
08-18 11:36:09.078: E/AndroidRuntime(1232): Caused by: java.lang.reflect.InvocationTargetException
08-18 11:36:09.078: E/AndroidRuntime(1232):     at java.lang.reflect.Method.invokeNative(Native Method)
08-18 11:36:09.078: E/AndroidRuntime(1232):     at java.lang.reflect.Method.invoke(Method.java:515)
08-18 11:36:09.078: E/AndroidRuntime(1232):     at android.view.View$1.onClick(View.java:3818)
08-18 11:36:09.078: E/AndroidRuntime(1232):     ... 11 more
08-18 11:36:09.078: E/AndroidRuntime(1232): Caused by: android.content.ActivityNotFoundException: Unable to find explicit activity class {com.johncorser.myapp/com.johncorser.myapp.SwitchedActivity}; have you declared this activity in your AndroidManifest.xml?
08-18 11:36:09.078: E/AndroidRuntime(1232):     at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:1628)
08-18 11:36:09.078: E/AndroidRuntime(1232):     at android.app.Instrumentation.execStartActivity(Instrumentation.java:1424)
08-18 11:36:09.078: E/AndroidRuntime(1232):     at android.app.Activity.startActivityForResult(Activity.java:3424)
08-18 11:36:09.078: E/AndroidRuntime(1232):     at android.app.Activity.startActivityForResult(Activity.java:3385)
08-18 11:36:09.078: E/AndroidRuntime(1232):     at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:839)
08-18 11:36:09.078: E/AndroidRuntime(1232):     at android.app.Activity.startActivity(Activity.java:3627)
08-18 11:36:09.078: E/AndroidRuntime(1232):     at android.app.Activity.startActivity(Activity.java:3595)
08-18 11:36:09.078: E/AndroidRuntime(1232):     at com.johncorser.myapp.MainActivity.buttonPressed(MainActivity.java:40)
08-18 11:36:09.078: E/AndroidRuntime(1232):     ... 14 more

公平警告，我可能做了一些非常愚蠢的事情，我是新人。

Answer 1

答案在于你的logcat：

08-18 11：36：09.078：E / AndroidRuntime（1232）：引起：android.content.ActivityNotFoundException：无法找到显式活动类{com.johncorser.myapp / com.johncorser.myapp.SwitchedActivity};你有没有在AndroidManifest.xml中声明这个活动？

所以将它添加到您的清单中就像这样

<activity
        android:name="SwitchedActivity"
        android:label="Switched">
</activity>

每当您添加新活动时，请务必将其添加到您的清单。

Answer 2

我非常确定您没有在AndroidManifest.xml文件中声明第二项活动。

你应该在你的清单中：

<application ... >

    <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=".SwitchedActivity"
        ... >
    </activity>

    ...
</application>

Answer 3

将第二个活动添加到清单文件中。您发布的日志清楚地说明了问题。

将以下内容添加到您的清单中：

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

请确保您下次阅读logcats或google logcat消息。

Android新手，无法在意图之间切换

3 个答案: