Android 无法实例化活动:未在路径上找到类 [英] Android Unable to instantiate activity: Didn't find class on path

问题描述

我已经将项目导入到 eclipse 中，当我尝试运行它时，会抛出此异常:

I've imported project into eclipse and when I try to run it, then this exception is thrown:

java.lang.RuntimeException:无法实例化活动 ComponentInfo{com.polygraf/com.polygraf.activity.Dashboard}:java.lang.ClassNotFoundException:未找到类com.polygraf.activity.Dashboard" 在路径上:/data/app/com.polygraf-1.apk

我尝试清理项目，然后检查所有类名和清单是否正常，但仍然找不到发生这种情况的原因.你能帮我一点吗?

I've tried to clean the project, then check if all class names and manifest are ok, but still can't find why this happens. Can you help me a little please?

仪表板类:

public class Dashboard extends FragmentActivity {

private static final String WELCOME_TYPE = "WELCOME_TYPE";
private static final String HELP_TYPE = "HELP_TYPE";

public static final String ADRESS_CONTENT = "ADRESS_CONTENT";
public static final String DOC_NAME = "DOC_NAME";

private Transcript mContent;
private ISettableContent mListOfDocument;

private String mAddress;

private String mDocName;

public Dashboard() {
}

/** Called with the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.dashboard);

    boolean content = false;
    // View gc = (NoSaveStateFrameLayout)
    // findViewById(R.id.content_fragment);
    //

    Fragment frContent = getSupportFragmentManager().findFragmentById(R.id.content_fragment);
    mContent = ((IGetContent) frContent).getContent();
    TranscriptSetting cc = Polygraf.getInstance().getContentSetting();

    Fragment frDocumentsList = getSupportFragmentManager().findFragmentById(R.id.documents);
    mListOfDocument = (ISettableContent) frDocumentsList;
    cc.registerContent(mListOfDocument);

    if (getIntent().hasExtra(ADRESS_CONTENT)) {
        mAddress = getIntent().getStringExtra(ADRESS_CONTENT);
        mDocName = getIntent().getStringExtra(DOC_NAME);
        mContent.setAddress(mAddress, mDocName);
        content = true;
    } else if (getIntent().hasExtra(WELCOME_TYPE)) {
        content = true;
        prepareVisibilityBtnTranscript();
    } else if (getIntent().hasExtra(HELP_TYPE)) {
        content = true;
        mContent.showHelp();

    }

    if (content) {
        FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
        ft.hide(frDocumentsList);
        ft.commit();

        // because on diferent layouts for small and large device
        // some views missing, so the test is inportant
        View contentLayout = findViewById(R.id.contentLayout);
        if (contentLayout != null) {
            contentLayout.setVisibility(View.VISIBLE);
        }
        prepareVisibilityBtnWelcome();
        // cp.setContent(mContent);
    }

    cc.registerContent(mContent);
    // cp.setListener(cc);

}
    .
    .
    .
}

和清单文件:

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.CHANGE_WIFI_MULTICAST_STATE" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />

<uses-sdk
    android:minSdkVersion="7"
    android:targetSdkVersion="17" />

<application
    android:name=".Polygraf"
    android:allowBackup="true"
    android:hardwareAccelerated="true"
    android:icon="@drawable/icon"
    android:label="@string/skeleton_app"
    android:theme="@android:style/Theme.Black.NoTitleBar" >
    <activity
        android:name="com.polygraf.activity.Dashboard"
        android:configChanges="orientation|keyboard" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <!-- This places this activity into the main app list. -->
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity
        android:name="com.polygraf.activity.SettingActivity"
        android:label="@string/skeleton_app" />
    <activity
        android:name="com.polygraf.activity.ContentActivity"
        android:label="@string/skeleton_app" >
    </activity>
    <activity
        android:name="com.polygraf.activity.PlayVideo"
        android:configChanges="orientation|keyboard"
        android:label="@string/skeleton_app" />
</application>

推荐答案

我想您正在使用 Eclipse.您的活动在那里没问题，但是 Eclipse 没有在 APK 中包含支持包...如果您查看堆栈跟踪中的错误上方，您会注意到问题的根源:Unable to find FragmentActivity".或者，您可以解压缩 apk，对其进行解压缩，您将看到不包含兼容包类.

I suppose you're using Eclipse. Your activity is there alright, but Eclipse didn't include the support package in the APK ... If you look above your error in stacktrace you will notice the root of your problem: "Unable to find FragmentActivity". Or you can unpack the apk, undex it and you will see the compatibility package classes were not included.

要解决此问题，请右键单击您的项目、属性、构建路径并转到导出选项卡.确保选中Android 私有库".一个干净和重建应该让你走上正轨......

To fix this, right-click your project, properties, build path and go to export tab. There make sure "Android private libraries" are checked. A clean and rebuild should put you on track ...

这篇关于Android 无法实例化活动:未在路径上找到类的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！