我遇到了一个问题,我有一个列表视图,我想在按钮点击时从中删除一个项目。我可以在互联网上找到例子,但我不能让他们工作。我怎样才能做到这一点?
这是我的代码:
public class GroupRequestCustomAdapter extends BaseAdapter {
String [] result;
Context context;
String [] imageId;
String [] groupId;
private static LayoutInflater inflater=null;
public GroupRequestCustomAdapter(GroupRequests ListActivity, String[] prgmNameList, String[] prgmImages, String [] GroupId) {
// TODO Auto-generated constructor stub
result=prgmNameList;
context=ListActivity;
imageId=prgmImages;
groupId = GroupId;
inflater = ( LayoutInflater )context.
getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return result.length;
}
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return position;
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return position;
}
public class Holder
{
TextView tv;
ImageView img;
Button accept;
Button decline;
}
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
Holder holder=new Holder();
View rowView;
//Bitmap bitmap = BitmapFactory.decodeResource(context.getResources(), imageId[position]);
//Bitmap bitmap = getBitmapFromURL(imageId[position]);
rowView = inflater.inflate(R.layout.group_request_list, null);
holder.tv=(TextView) rowView.findViewById(R.id.textView1);
holder.img=(ImageView) rowView.findViewById(R.id.imageView1);
holder.tv.setText(result[position]);
holder.accept=(Button) rowView.findViewById(R.id.buttonAccept);
holder.decline=(Button) rowView.findViewById(R.id.buttonDecline);
if (holder.img != null) {
new GetImageFromUrl(holder.img,context).execute(imageId[position]);
}
holder.accept.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Log.v("Button click", "accept");
}
});
holder.decline.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Log.v("Button click", "Decline");
}
});
return rowView;
}
}
答案 0 :(得分:1)
您可以在适配器中添加方法来为您执行此操作:
public void deleteItem (int position) {
result.remove(position);
// remove(int) does not exist for arrays, you would have to write that method yourself or use a List instead of an array
notifyDataSetChanged();
}
public void deleteItem (String itemToDelete) {
result.remove(itemToDelete);
// remove(int) does not exist for arrays, you would have to write that method yourself or use a List instead of an array
notifyDataSetChanged();
}
顺便说一句,您的getItem(int position)
实施错误,应该返回result.get(position)
。 getItemId
也应该返回一个有意义的ID;在你的情况下,我认为返回的位置很好。
编辑:
我注意到你的构造函数有3个不同的列表。因此,您很难处理数据集中的更改,因为如果从结果中删除项目,则还必须从其他列表中删除相应的项目。我强烈建议您重新定义适配器,如下所示:
public GroupRequestCustomAdapter(GroupRequests ListActivity, List<MyObject>)
MyObject将是一个非常简单的类,包含ListView中一个项目的数据,例如:
public class MyObject {
private String prgmName;
private String prgmImage;
// other required fields.
// required getters/setters
}
这样,您只需要在适配器内部管理一个列表,而不是像现在这样管理result
,imageId
和groupId
。可以在List上调用remove(int position)。
最后,您还可以考虑延长ArrayAdapter而不是BaseAdapter
,它有一些BaseAdapter
没有用的有用方法,包括......您猜对了: remove方法;)