我的程序有两个选项卡，每个选项卡都必须创建片段。我刚开始使用一个选项卡，程序运行时出错。可以帮助我。
Main Java。
package com.example.version1;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentTabHost;
public class MainActivity extends FragmentActivity {
// Fragment TabHost as mTabHost
private FragmentTabHost mTabHost;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mTabHost = (FragmentTabHost)findViewById(android.R.id.tabhost);
mTabHost.setup(this, getSupportFragmentManager(), R.id.realtabcontent);
mTabHost.addTab(mTabHost.newTabSpec("Line1").setIndicator("Line1"),
Tab1Fragment.class, null);
mTabHost.addTab(mTabHost.newTabSpec("Line2").setIndicator("Tab2"),
Tab2Fragment.class, null);
}
}
Tab1.java（此类已为片段创建）
package com.example.version1;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
public class Tab1Fragment extends FragmentActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.tab1_view);
ViewPager pager = (ViewPager) findViewById(R.id.viewpager);
pager.setAdapter(new MyPagerAdapter(getSupportFragmentManager()));
}
private class MyPagerAdapter extends FragmentPagerAdapter {
public MyPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int pos)
{
return Machine1.newInstance("Machine1");
}
@Override
public int getCount() {
return 4;
}
}
}
Machine1.java
package com.example.version1;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class Machine1 extends Fragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.machine1, container, false);
// TextView tv = (TextView) v.findViewById(R.id.tvFragFirst);
// tv.setText(getArguments().getString("msg"));
return v;
}
public static Machine1 newInstance(String text) {
Machine1 f = new Machine1();
Bundle b = new Bundle();
b.putString("msg", text);
f.setArguments(b);
return f;
}
}
我得到的错误是：
02-22 18:53:22.100: D/AndroidRuntime(2394): Shutting down VM
02-22 18:53:22.120: W/dalvikvm(2394): threadid=1: thread exiting with uncaught exception (group=0x41465700)
02-22 18:53:22.230: E/AndroidRuntime(2394): FATAL EXCEPTION: main
02-22 18:53:22.230: E/AndroidRuntime(2394): java.lang.ClassCastException: com.example.version1.Tab1Fragment cannot be cast to android.support.v4.app.Fragment
02-22 18:53:22.230: E/AndroidRuntime(2394): at android.support.v4.app.Fragment.instantiate(Fragment.java:402)
02-22 18:53:22.230: E/AndroidRuntime(2394): at android.support.v4.app.FragmentTabHost.doTabChanged(FragmentTabHost.java:343)
02-22 18:53:22.230: E/AndroidRuntime(2394): at android.support.v4.app.FragmentTabHost.onAttachedToWindow(FragmentTabHost.java:280)
02-22 18:53:22.230: E/AndroidRuntime(2394): at android.view.View.dispatchAttachedToWindow(View.java:12125)
02-22 18:53:22.230: E/AndroidRuntime(2394): at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2453)
02-22 18:53:22.230: E/AndroidRuntime(2394): at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2460)
02-22 18:53:22.230: E/AndroidRuntime(2394): at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2460)
02-22 18:53:22.230: E/AndroidRuntime(2394): at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2460)
02-22 18:53:22.230: E/AndroidRuntime(2394): at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1207)
02-22 18:53:22.230: E/AndroidRuntime(2394): at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1004)
02-22 18:53:22.230: E/AndroidRuntime(2394): at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5481)
02-22 18:53:22.230: E/AndroidRuntime(2394): at android.view.Choreographer$CallbackRecord.run(Choreographer.java:749)
02-22 18:53:22.230: E/AndroidRuntime(2394): at android.view.Choreographer.doCallbacks(Choreographer.java:562)
02-22 18:53:22.230: E/AndroidRuntime(2394): at android.view.Choreographer.doFrame(Choreographer.java:532)
02-22 18:53:22.230: E/AndroidRuntime(2394): at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:735)
02-22 18:53:22.230: E/AndroidRuntime(2394): at android.os.Handler.handleCallback(Handler.java:730)
02-22 18:53:22.230: E/AndroidRuntime(2394): at android.os.Handler.dispatchMessage(Handler.java:92)
02-22 18:53:22.230: E/AndroidRuntime(2394): at android.os.Looper.loop(Looper.java:137)
02-22 18:53:22.230: E/AndroidRuntime(2394): at android.app.ActivityThread.main(ActivityThread.java:5103)
02-22 18:53:22.230: E/AndroidRuntime(2394): at java.lang.reflect.Method.invokeNative(Native Method)
02-22 18:53:22.230: E/AndroidRuntime(2394): at java.lang.reflect.Method.invoke(Method.java:525)
02-22 18:53:22.230: E/AndroidRuntime(2394): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
02-22 18:53:22.230: E/AndroidRuntime(2394): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
02-22 18:53:22.230: E/AndroidRuntime(2394): at dalvik.system.NativeStart.main(Native Method)
02-22 18:53:26.620: I/Process(2394): Sending signal. PID: 2394 SIG: 9
答案 0 :(得分：0)
你的问题来自这些方面：
mTabHost.addTab(mTabHost.newTabSpec("Line1").setIndicator("Line1"),
Tab1Fragment.class, null);
mTabHost.addTab(mTabHost.newTabSpec("Line2").setIndicator("Tab2"),
Tab2Fragment.class, null);
Tab1Fragment.class和Tab1Fragment.class属于FragmentActivity类型，其中addTab方法需要一种Fragment类型。我相信你想要使用Machine1.class。