我已经有一段时间了,经过几次失败的尝试,我非常接近实现我所追求的目标。我从这个网站上挖掘了各种答案,最有帮助的是:-
我已经在我的程序中实现了所有 Harlo 的代码片段,但我遇到了一个问题。
当我运行应用程序时,我点击列表项以加载“核心”片段,当它崩溃时,我得到可怕的“不幸的是应用程序已停止”。
我的片段代码在下面,我突出显示了违规行,我还包括了 logcat 的相关部分。
任何帮助将不胜感激。
谢谢你
加里
import android.app.Activity;
import android.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.os.Bundle;
import android.widget.Button;
import android.widget.RelativeLayout;
import android.view.View.OnClickListener;
public class CoreFragment extends Fragment{
int index;
Button Button1,Button2,Button3;
String Str;
OnDataPass dataPasser;
@Override
public void onAttach(Activity a) {
super.onAttach(a);
dataPasser = (OnDataPass) a;
}
public static CoreFragment newInstance(int index) {
CoreFragment coreFragment = new CoreFragment();
coreFragment.index = index;
return coreFragment;
}
public interface OnDataPass {
public void onDataPass(String data);
}
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
if (container == null) {
// We have different layouts, and in one of them this
// fragment's containing frame doesn't exist. The fragment
// may still be created from its saved state, but there is
// no reason to try to create its view hierarchy because it
// won't be displayed. Note this is not needed -- we could
// just run the code below, where we would create and return
// the view hierarchy; it would just never be used.
return null;
}
RelativeLayout mRelativeLayout = (RelativeLayout) inflater.inflate(R.layout.corefragment,
container, false);
Button Button1 = (Button) mRelativeLayout.findViewById(R.id.Button1);
Button1.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Str = "I ";
passData(Str);
}
public void passData(String data) {
data = Str;
dataPasser.onDataPass(data);
}
});
return mRelativeLayout;
}
}//end
日志猫
01-18 12:19:18.430: W/dalvikvm(1601): threadid=1: thread exiting with uncaught exception (group=0x40acf228)
01-18 12:19:18.440: E/AndroidRuntime(1601): FATAL EXCEPTION: main
01-18 12:19:18.440: E/AndroidRuntime(1601): java.lang.ClassCastException: com.epsilonitsystems.fragger.MainActivity cannot be cast to com.epsilonitsystems.fragger.CoreFragment$OnDataPass
01-18 12:19:18.440: E/AndroidRuntime(1601): at com.epsilonitsystems.fragger.CoreFragment.onAttach(CoreFragment.java:25)
嗨,TNR,谢谢你,正如我对 Fragment 所说的那样,它们被证明是一种真正的痛苦!我已经添加了您建议的行,现在我崩溃了!LogCat 如下。感谢您到目前为止的帮助,我很高兴能把这个整理好!!
01-23 15:30:40.659: W/dalvikvm(3098): threadid=1: thread exiting with uncaught exception (group=0x40acf228)
01-23 15:30:40.749: E/AndroidRuntime(3098): FATAL EXCEPTION: main
01-23 15:30:40.749: E/AndroidRuntime(3098): java.lang.NullPointerException
01-23 15:30:40.749: E/AndroidRuntime(3098): at com.epsilonitsystems.fragger.MainActivity.onDataPass(MainActivity.java:33)
01-23 15:30:40.749: E/AndroidRuntime(3098): at com.epsilonitsystems.fragger.CoreFragment$1.passData(CoreFragment.java:69)
01-23 15:30:40.749: E/AndroidRuntime(3098): at com.epsilonitsystems.fragger.CoreFragment$1.onClick(CoreFragment.java:62)
01-23 15:30:40.749: E/AndroidRuntime(3098): at android.view.View.performClick(View.java:3549)
01-23 15:30:40.749: E/AndroidRuntime(3098): at android.view.View$PerformClick.run(View.java:14393)
01-23 15:30:40.749: E/AndroidRuntime(3098): at android.os.Handler.handleCallback(Handler.java:605)
01-23 15:30:40.749: E/AndroidRuntime(3098): at android.os.Handler.dispatchMessage(Handler.java:92)
01-23 15:30:40.749: E/AndroidRuntime(3098): at android.os.Looper.loop(Looper.java:154)
01-23 15:30:40.749: E/AndroidRuntime(3098): at android.app.ActivityThread.main(ActivityThread.java:4945)
01-23 15:30:40.749: E/AndroidRuntime(3098): at java.lang.reflect.Method.invokeNative(Native Method)
01-23 15:30:40.749: E/AndroidRuntime(3098): at java.lang.reflect.Method.invoke(Method.java:511)
01-23 15:30:40.749: E/AndroidRuntime(3098): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
01-23 15:30:40.749: E/AndroidRuntime(3098): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
01-23 15:30:40.749: E/AndroidRuntime(3098): at dalvik.system.NativeStart.main(Native Method)
再次感谢。