因此,现在我有一个自定义适配器类,它接收一个位置数组并将它们添加到ListView中。这一切都很好,很好,但是我想在这个初始化之后向这个列表视图添加位置。例如,有人可以“添加一个位置”并将其添加到这个ListView中。以下是我的主要活动:
package com.example.listviewtest;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.ListView;
public class MainActivity extends Activity {
private ListView listView1;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Location location_data[] = new Location[]
{
new Location(R.drawable.ic_launcher, "Location 1", "Fruit!", "2 miles", "8-4 mon-fri\nclosed sun"),
new Location(R.drawable.ic_launcher, "Location 2", "Veggies!", "2 miles", "8-5"),
new Location(R.drawable.ic_launcher, "Location 3", "Plants!", "2 miles", "8-5"),
new Location(R.drawable.ic_launcher, "Location 4", "Flowers!", "2 miles", "8-5"),
new Location(R.drawable.ic_launcher, "Location 5", "Baked Goods!", "2 miles", "8-5")
};
LocationAdapter adapter = new LocationAdapter(this,
R.layout.listview_item_row, location_data);
//adapter.add(new Location(R.drawable.ic_launcher, "Location 6", "Veggies!", "2 miles", "8-5"));
listView1 = (ListView)findViewById(R.id.listView1);
View header = (View)getLayoutInflater().inflate(R.layout.listview_header_row, null);
listView1.addHeaderView(header);
listView1.setAdapter(adapter);
}
}
这个很管用。现在,在用数组填充adapter.add(new Location(R.drawable.ic_launcher, "Location 6", "Veggies!", "2 miles", "8-5"));
之后,我想做一些类似的事情。
这是我的LocationAdapter课程:
package com.example.listviewtest;
import android.app.Activity;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;
public class LocationAdapter extends ArrayAdapter<Location>{
Context context;
int layoutResourceId;
Location data[] = null;
public LocationAdapter(Context context, int layoutResourceId, Location[] data) {
super(context, layoutResourceId, data);
this.layoutResourceId = layoutResourceId;
this.context = context;
this.data = data;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View row = convertView;
LocationHolder holder = null;
if(row == null)
{
LayoutInflater inflater = ((Activity)context).getLayoutInflater();
row = inflater.inflate(layoutResourceId, parent, false);
holder = new LocationHolder();
holder.imgIcon = (ImageView)row.findViewById(R.id.imgIcon);
holder.txtTitle = (TextView)row.findViewById(R.id.txtTitle);
holder.details = (TextView)row.findViewById(R.id.details);
holder.distance = (TextView)row.findViewById(R.id.distance);
holder.hours = (TextView)row.findViewById(R.id.hours);
row.setTag(holder);
}
else
{
holder = (LocationHolder)row.getTag();
}
Location location = data[position];
holder.txtTitle.setText(location.title);
holder.imgIcon.setImageResource(location.icon);
holder.details.setText(location.details);
holder.distance.setText(location.distance);
holder.hours.setText(location.hours);
return row;
}
static class LocationHolder
{
ImageView imgIcon;
TextView txtTitle;
TextView details;
TextView distance;
TextView hours;
}
}
对我如何实现这一点有什么想法吗?谢谢。
发布于 2014-05-29 18:12:35
Locations data[]
从数组更改为ArrayList<Location>
,并覆盖适当的构造函数。data
设置为字段(键入ArrayList<Location>
)data.add(location)
notifyDatasetChanged()
。示例代码。
发布于 2014-05-29 18:12:42
将数据存储在ArrayList<Location>
中而不仅仅是Location[]
中,然后在列表适配器中创建一个公共类:
ArrayList<Location> data = new ArrayList<Location>();
@Override
public void add(Location location) {
data.add(location);
notifyDataSetChanged();
}
然后,当您想要向列表中添加一个项时,只需调用location_data.add(new_location)
。
编辑:,看上去你是从几个基本相同的答案中挑选出来的。
发布于 2014-05-29 18:16:56
看起来,您需要重写LocationAdapter类中的add方法,以便将对象添加到内部列表中。
@Override
public void add(Location location)
{
super.add(location);
data.add(location);
}
此实现要求您将数据更改为ArrayList,而不仅仅是数组,否则您必须自己重新调整数组的大小。
ArrayList<Location> data = null; // Alternatively use new ArrayList<Location>();
如果不这样做,内部数据将保持不变,调用add将不会更改列表。这是不好的,因为您使用数据变量来获取视图的值。
https://stackoverflow.com/questions/23939800
复制相似问题