我想在Fragement中做一个自定义的GridView
,
使用 URLHTTP 获取 url 并使用 Bitmap
。
但我只完成了一半,
我无法打开 MapFragement
页面并且找不到我的
bug 很长时间都解决不了问题,请帮帮我。
请帮助或尝试提供一些想法如何实现这一目标,
谢谢!
我的代码:
item_gridview_member.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<ImageView
android:id="@+id/imgmember"
android:layout_width="match_parent"
android:layout_height="wrap_content"
/>
</RelativeLayout>
fragement_member.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
android:orientation="vertical" xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MemberFragment">
<GridView
android:id="@+id/gridmember"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:columnWidth="150dp"
android:stretchMode="columnWidth"
android:numColumns="3"
android:verticalSpacing="3dp"
android:layout_marginBottom="3dp">
</GridView>
CImage.java
import android.graphics.Bitmap;
public class CImage {
private String imagePath;
private Bitmap bitmap;
public CImage(String imagePath, Bitmap bitmap) {
this.imagePath = imagePath;
this.bitmap = bitmap;
}
public String getImagePath() {
return imagePath;
}
public void setImagePath(String imagePath) {
this.imagePath = imagePath;
}
public Bitmap getBitmap() {
return bitmap;
}
public void setBitmap(Bitmap bitmap) {
this.bitmap = bitmap;
}
}
GridViewAdapter.java
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import com.example.yao.pm.R;
import java.util.List;
public class GridViewAdapter extends BaseAdapter {
private LayoutInflater myInflater;
private List<CImage> ImgList;
public GridViewAdapter(Context context,List<CImage> ImgList) {
myInflater = LayoutInflater.from(context);
this.ImgList = ImgList;
}
@Override
public int getCount() {
return ImgList.size();
}
@Override
public Object getItem(int position) {
return ImgList.get(position);
}
@Override
public long getItemId(int position) {
return 0;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder = null;
if(convertView == null)
{
convertView = myInflater.inflate(R.layout.item_gridview_member,null);
holder = new ViewHolder();
holder.imageView = convertView.findViewById(R.id.image_meme);
convertView.setTag(holder);
}
CImage image = ImgList.get(position);
holder.imageView.setImageBitmap(image.getBitmap());
if (image.getBitmap() == null) {
holder.imageView.setImageResource(R.mipmap.ic_launcher);
} else {
holder.imageView.setImageBitmap(image.getBitmap());
}
return convertView;
}
public class ViewHolder {
ImageView imageView;
}
}
MapFregement.java
public class MemberFragment extends Fragment {
private GridViewAdapter adapter;
private ArrayList<CImage> imageList;
public MemberFragment() {
// Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_member, container, false);
}
@Override
public void onActivityCreated(@Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
inital();
adapter = new GridViewAdapter(getActivity(),imageList);
grieview.setAdapter(adapter);
}
public void inital(){
grieview = getActivity().findViewById(R.id.gridmember);
}
GridView grieview;
}
谢谢!!
最佳答案
查看代码后,我认为问题出在 MemberFragment
类中的 GridView
。
您正在使用 inflater 将 View 膨胀为 fragment ,并尝试使用 Activity 上下文解析 id。此外,您需要覆盖 Fragment 中的 onViewCreated()
。
What is usage of
onViewCreated()
?Called immediately after
onCreateView(LayoutInflater, ViewGroup, Bundle)
has returned, but before any saved state has been restored in to the view. This gives subclasses a chance to initialize themselves once they know their view hierarchy has been completely created. The fragment's view hierarchy is not however attached to its parent at this point.
您的MemberFragment.java:
public class MemberFragment extends Fragment {
private GridView grieview;
private GridViewAdapter adapter;
private ArrayList<CImage> imageList;
public MemberFragment() {
// Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_member, container, false);
}
//Note: Change is from here, Instead of onActivityCreated(), override this method. Use View object from it.
@Override
void onViewCreated (View view, Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
inital(view); // Get the View Object provided from method parameter to find your fragment layout view IDs, It's the same View you return in onCreateView method.
adapter = new GridViewAdapter(getActivity(),imageList);
grieview.setAdapter(adapter);
}
public void inital(View view){
grieview = view.findViewById(R.id.gridmember); //Find your view inside fragment like this.
}
}
希望对你有帮助!
关于Android GridView(自定义) fragment 图片,但是打不开页面,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/52542372/