我试图在android中实现滑动+标签，但我现在有这个问题。当我启动我的应用程序时，我在logCat中得到它：
02-24 18:42:16.062: E/AndroidRuntime(12322): FATAL EXCEPTION: main
02-24 18:42:16.062: E/AndroidRuntime(12322): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.test/com.test.TabsViewPagerFragmentActivity}: java.lang.ClassCastException: com.test.ScanQR cannot be cast to android.support.v4.app.Fragment
02-24 18:42:16.062: E/AndroidRuntime(12322): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1967)
02-24 18:42:16.062: E/AndroidRuntime(12322): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1992)
02-24 18:42:16.062: E/AndroidRuntime(12322): at android.app.ActivityThread.access$600(ActivityThread.java:127)
02-24 18:42:16.062: E/AndroidRuntime(12322): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1158)
02-24 18:42:16.062: E/AndroidRuntime(12322): at android.os.Handler.dispatchMessage(Handler.java:99)
02-24 18:42:16.062: E/AndroidRuntime(12322): at android.os.Looper.loop(Looper.java:137)
02-24 18:42:16.062: E/AndroidRuntime(12322): at android.app.ActivityThread.main(ActivityThread.java:4441)
02-24 18:42:16.062: E/AndroidRuntime(12322): at java.lang.reflect.Method.invokeNative(Native Method)
02-24 18:42:16.062: E/AndroidRuntime(12322): at java.lang.reflect.Method.invoke(Method.java:511)
02-24 18:42:16.062: E/AndroidRuntime(12322): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
02-24 18:42:16.062: E/AndroidRuntime(12322): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
02-24 18:42:16.062: E/AndroidRuntime(12322): at dalvik.system.NativeStart.main(Native Method)
02-24 18:42:16.062: E/AndroidRuntime(12322): Caused by: java.lang.ClassCastException: com.test.ScanQR cannot be cast to android.support.v4.app.Fragment
02-24 18:42:16.062: E/AndroidRuntime(12322): at android.support.v4.app.Fragment.instantiate(Fragment.java:402)
02-24 18:42:16.062: E/AndroidRuntime(12322): at android.support.v4.app.Fragment.instantiate(Fragment.java:377)
02-24 18:42:16.062: E/AndroidRuntime(12322): at com.test.TabsViewPagerFragmentActivity.intialiseViewPager(TabsViewPagerFragmentActivity.java:123)
02-24 18:42:16.062: E/AndroidRuntime(12322): at com.test.TabsViewPagerFragmentActivity.onCreate(TabsViewPagerFragmentActivity.java:103)
02-24 18:42:16.062: E/AndroidRuntime(12322): at android.app.Activity.performCreate(Activity.java:4465)
02-24 18:42:16.062: E/AndroidRuntime(12322): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
02-24 18:42:16.062: E/AndroidRuntime(12322): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1931)
02-24 18:42:16.062: E/AndroidRuntime(12322): ... 11 more
这是我的代码：
public class TabsViewPagerFragmentActivity extends FragmentActivity implements
TabHost.OnTabChangeListener, ViewPager.OnPageChangeListener {
private TabHost mTabHost;
private ViewPager mViewPager;
private HashMap<String, TabInfo> mapTabInfo = new HashMap<String, TabsViewPagerFragmentActivity.TabInfo>();
private PagerAdapter mPagerAdapter;
/**
*
* @author mwho Maintains extrinsic info of a tab's construct
*/
private class TabInfo {
private String tag;
private Class<?> clss;
private Bundle args;
private Fragment fragment;
TabInfo(String tag, Class<?> clazz, Bundle args) {
this.tag = tag;
this.clss = clazz;
this.args = args;
}
}
/**
* A simple factory that returns dummy views to the Tabhost
*
* @author mwho
*/
class TabFactory implements TabContentFactory {
private final Context mContext;
/**
* @param context
*/
public TabFactory(Context context) {
mContext = context;
}
/**
* (non-Javadoc)
*
* @see android.widget.TabHost.TabContentFactory#createTabContent(java.lang.String)
*/
public View createTabContent(String tag) {
View v = new View(mContext);
v.setMinimumWidth(0);
v.setMinimumHeight(0);
return v;
}
}
/**
* (non-Javadoc)
*
* @see android.support.v4.app.FragmentActivity#onCreate(android.os.Bundle)
*/
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Inflate the layout
setContentView(R.layout.tabs_viewpager_layout);
// Initialise the TabHost
this.initialiseTabHost(savedInstanceState);
if (savedInstanceState != null) {
mTabHost.setCurrentTabByTag(savedInstanceState.getString("tab")); // set
// the
// tab
// as
// per
// the
// saved
// state
}
// Intialise ViewPager
this.intialiseViewPager();
}
/**
* (non-Javadoc)
*
* @see android.support.v4.app.FragmentActivity#onSaveInstanceState(android.os.Bundle)
*/
protected void onSaveInstanceState(Bundle outState) {
outState.putString("tab", mTabHost.getCurrentTabTag()); // save the tab
// selected
super.onSaveInstanceState(outState);
}
/**
* Initialise ViewPager
*/
private void intialiseViewPager() {
List<Fragment> fragments = new Vector<Fragment>();
fragments.add(Fragment.instantiate(this, ScanQR.class.getName()));
fragments.add(Fragment.instantiate(this, InsertCode.class.getName()));
fragments.add(Fragment.instantiate(this, Guide.class.getName()));
this.mPagerAdapter = new PagerAdapter(
super.getSupportFragmentManager(), fragments);
//
this.mViewPager = (ViewPager) super.findViewById(R.id.viewpager);
this.mViewPager.setAdapter(this.mPagerAdapter);
this.mViewPager.setOnPageChangeListener(this);
}
/**
* Initialise the Tab Host
*/
private void initialiseTabHost(Bundle args) {
mTabHost = (TabHost) findViewById(android.R.id.tabhost);
mTabHost.setup();
TabInfo tabInfo = null;
TabsViewPagerFragmentActivity.AddTab(this, this.mTabHost, this.mTabHost
.newTabSpec("Tab1").setIndicator("Tab 1"),
(tabInfo = new TabInfo("Tab1", ScanQR.class, args)));
this.mapTabInfo.put(tabInfo.tag, tabInfo);
TabsViewPagerFragmentActivity.AddTab(this, this.mTabHost, this.mTabHost
.newTabSpec("Tab2").setIndicator("Tab 2"),
(tabInfo = new TabInfo("Tab2", InsertCode.class, args)));
this.mapTabInfo.put(tabInfo.tag, tabInfo);
TabsViewPagerFragmentActivity.AddTab(this, this.mTabHost, this.mTabHost
.newTabSpec("Tab3").setIndicator("Tab 3"),
(tabInfo = new TabInfo("Tab3", Guide.class, args)));
this.mapTabInfo.put(tabInfo.tag, tabInfo);
// Default to first tab
// this.onTabChanged("Tab1");
//
mTabHost.setOnTabChangedListener(this);
}
/**
* Add Tab content to the Tabhost
*
* @param activity
* @param tabHost
* @param tabSpec
* @param clss
* @param args
*/
private static void AddTab(TabsViewPagerFragmentActivity activity,
TabHost tabHost, TabHost.TabSpec tabSpec, TabInfo tabInfo) {
// Attach a Tab view factory to the spec
tabSpec.setContent(activity.new TabFactory(activity));
tabHost.addTab(tabSpec);
}
/**
* (non-Javadoc)
*
* @see android.widget.TabHost.OnTabChangeListener#onTabChanged(java.lang.String)
*/
public void onTabChanged(String tag) {
// TabInfo newTab = this.mapTabInfo.get(tag);
int pos = this.mTabHost.getCurrentTab();
this.mViewPager.setCurrentItem(pos);
}
/*
* (non-Javadoc)
*
* @see
* android.support.v4.view.ViewPager.OnPageChangeListener#onPageScrolled
* (int, float, int)
*/
@Override
public void onPageScrolled(int position, float positionOffset,
int positionOffsetPixels) {
// TODO Auto-generated method stub
}
/*
* (non-Javadoc)
*
* @see
* android.support.v4.view.ViewPager.OnPageChangeListener#onPageSelected
* (int)
*/
@Override
public void onPageSelected(int position) {
// TODO Auto-generated method stub
this.mTabHost.setCurrentTab(position);
}
/*
* (non-Javadoc)
*
* @see android.support.v4.view.ViewPager.OnPageChangeListener#
* onPageScrollStateChanged(int)
*/
@Override
public void onPageScrollStateChanged(int state) {
// TODO Auto-generated method stub
}
}
和ScanQR类
public class ScanQR extends FragmentActivity implements OnQRCodeReadListener {
private QRCodeReaderView mydecoderview;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.scan_qr);
mydecoderview = (QRCodeReaderView) findViewById(R.id.qrdecoderview);
mydecoderview.setOnQRCodeReadListener(this);
}
// Called when a QR is decoded
// "text" : the text encoded in QR
// "points" : points where QR control points are placed
@Override
public void onQRCodeRead(String text, PointF[] points) {
// myTextView.setText(text);
Toast.makeText(this, text, Toast.LENGTH_SHORT).show();
}
// Called when your device have no camera
@Override
public void cameraNotFound() {
}
// Called when there's no QR codes in the camera preview image
@Override
public void QRCodeNotFoundOnCamImage() {
}
@Override
protected void onResume() {
super.onResume();
mydecoderview.getCameraManager().startPreview();
}
@Override
protected void onPause() {
super.onPause();
mydecoderview.getCameraManager().stopPreview();
}
}