我刚开始在iOS平台上开发后,在android平台上开发。我环顾四周,似乎无法弄清楚。 我想在选择操作栏中的选项卡后出现网格视图。该片段通过控制标签栏的主要活动进入视图。 我认为问题可能与传递上下文有关,但我不确定。图片GridView内部片段
这是我的MainActivity.java。这是片段初始化并附加到活动的位置。它在片段中没有代码的情况下工作。
if (mFragment == null){
mFragment = Fragment.instantiate(mActivity, mClass.getName());
ft.add(android.R.id.content,mFragment,mTag);
} else {
ft.attach(mFragment);
}
这是我PhotosFragment.java这就是我想要的网格视图,且能够显示。
public class PhotosFragment extends Fragment {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
GridView gridview = (GridView) this.getActivity().findViewById(R.id.photogridview);
gridview.setAdapter(new PhotoImageAdapter(this.getActivity()));
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
}
}
这里是我的PhotoImageAdapter.java类。这是图像添加到我认为适配器的地方。
public class PhotoImageAdapter extends BaseAdapter {
private Context mContext;
public PhotoImageAdapter(Context c) {
mContext = c;
}
public int getCount() {
return mThumbIds.length;
}
public Object getItem(int position) {
return null;
}
public long getItemId(int position) {
return 0;
}
public View getView(int position, View convertView, ViewGroup parent) {
ImageView imageView;
if (convertView == null) { // if it's not recycled, initialize some attributes
imageView = new ImageView(mContext);
imageView.setLayoutParams(new GridView.LayoutParams(85, 85));
imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
imageView.setPadding(8, 8, 8, 8);
} else {
imageView = (ImageView) convertView;
}
imageView.setImageResource(mThumbIds[position]);
return imageView;
}
private Integer[] mThumbIds = {
R.drawable.sample_2, R.drawable.sample_3,
R.drawable.sample_4, R.drawable.sample_5,
R.drawable.sample_6, R.drawable.sample_7,
R.drawable.sample_0, R.drawable.sample_1,
R.drawable.sample_2, R.drawable.sample_3,
R.drawable.sample_4, R.drawable.sample_5,
R.drawable.sample_6, R.drawable.sample_7,
R.drawable.sample_0, R.drawable.sample_1,
R.drawable.sample_2, R.drawable.sample_3,
R.drawable.sample_4, R.drawable.sample_5,
R.drawable.sample_6, R.drawable.sample_7
};
}
这里是我的photos_layout其中包含与photogridview id的gridview。 photos_layout.xml
<?xml version="1.0" encoding="utf-8"?>
<GridView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/photogridview"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:columnWidth="90dp"
android:numColumns="auto_fit"
android:verticalSpacing="10dp"
android:horizontalSpacing="10dp"
android:stretchMode="columnWidth"
android:gravity="center">
</GridView>
编辑
这里是日志报告时崩溃
05-29 14:15:43.895: W/dalvikvm(676): threadid=1: thread exiting with uncaught exception (group=0x409c01f8)
05-29 14:15:43.925: E/AndroidRuntime(676): FATAL EXCEPTION: main
05-29 14:15:43.925: E/AndroidRuntime(676): java.lang.NullPointerException
05-29 14:15:43.925: E/AndroidRuntime(676): at com.corecoders.PhotosFragment.onCreate(PhotosFragment.java:21)
05-29 14:15:43.925: E/AndroidRuntime(676): at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:795)
05-29 14:15:43.925: E/AndroidRuntime(676): at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1032)
05-29 14:15:43.925: E/AndroidRuntime(676): at android.app.BackStackRecord.run(BackStackRecord.java:622)
05-29 14:15:43.925: E/AndroidRuntime(676): at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1382)
05-29 14:15:43.925: E/AndroidRuntime(676): at android.app.FragmentManagerImpl$1.run(FragmentManager.java:426)
05-29 14:15:43.925: E/AndroidRuntime(676): at android.os.Handler.handleCallback(Handler.java:605)
05-29 14:15:43.925: E/AndroidRuntime(676): at android.os.Handler.dispatchMessage(Handler.java:92)
05-29 14:15:43.925: E/AndroidRuntime(676): at android.os.Looper.loop(Looper.java:137)
05-29 14:15:43.925: E/AndroidRuntime(676): at android.app.ActivityThread.main(ActivityThread.java:4424)
05-29 14:15:43.925: E/AndroidRuntime(676): at java.lang.reflect.Method.invokeNative(Native Method)
05-29 14:15:43.925: E/AndroidRuntime(676): at java.lang.reflect.Method.invoke(Method.java:511)
05-29 14:15:43.925: E/AndroidRuntime(676): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
05-29 14:15:43.925: E/AndroidRuntime(676): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
05-29 14:15:43.925: E/AndroidRuntime(676): at dalvik.system.NativeStart.main(Native Method)
05-29 14:15:44.494: I/dalvikvm(676): threadid=3: reacting to signal 3
05-29 14:15:44.514: I/dalvikvm(676): Wrote stack traces to '/data/anr/traces.txt'
05-29 14:20:43.995: I/Process(676): Sending signal. PID: 676 SIG: 9
应用程序崩溃时您单击该选项卡上,并且片段被初始化。 我正在遵循的教程是android developers网站上的教程。
任何帮助或解释将是惊人的。就像我说的,我是新手,所以能够有一些指导来帮助我理解正在发生的事情会很棒。
迪斯科
你缺少ft.commit()ft.add后()。 – ania
而且你需要onCreateView方法的片段 - 你应该阅读:http://developer.android.com/guide/topics/fundamentals/fragments.html – ania
好的,谢谢你的这些建议,但我仍然在这个问题上遇到这个问题点 gridview.setAdapter(new PhotoImageAdapter(this.getActivity())); – StuStirling