所以我遇到的问题是我有一个哈希表,其键值为
键:整数 值:ArrayList
在我的自定义 listView 适配器中,我将其设置为仅显示哈希表中特定位置的值..但目前它显示的是整个哈希表。我不太确定我做错了什么。这是适配器
注意:Statics.mainPageListPosition 是一个静态整数,当用户点击主屏幕上的某个位置时会设置它。然后我希望适配器显示该位置,并且仅显示该位置的数据。
package assignments;
import java.util.ArrayList;
import java.util.Hashtable;
import com.example.mt_study.R;
import com.example.statics.Statics;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.TextView;
import android.widget.Toast;
public class AssignmentListViewAdapter extends ArrayAdapter<Assignment> {
private LayoutInflater inflater;
private Hashtable<Integer, ArrayList<Assignment>> assignmentList;
// class used to hold views when the user scrolls on the listView
// it stores them and then we can re-use their id's as the user scrolls
// down or up the screen so we don't have to keep calling findViewById
private class assignmentViewHolder {
TextView Title;
TextView Date;
public assignmentViewHolder(TextView assignmentTitle, TextView Date) {
this.Title = assignmentTitle;
this.Date = Date;
}
public TextView getTitle() {
return Title;
}
public TextView getDate() {
return Date;
}
}
public AssignmentListViewAdapter(Context context,
Hashtable<Integer, ArrayList<Assignment>> data) {
super(context, R.id.assignment_row_title, R.id.assignment_row_date);
inflater = LayoutInflater.from(context);
assignmentList = data;
}
// set of functions useful for the getView function
public int getCount() {
return Statics.allAssignments.get(Statics.mainPageListPosition).size();
}
public Assignment getItem(int position) {
return assignmentList.get(Statics.mainPageListPosition).get(position);
}
public long getItemId(int position) {
return position;
}
public int getViewTypeCount() {
return 1;
}
public View getView(int position, View convertView, ViewGroup parent) {
// Assignment assignment = this.getItem(position);
TextView assignmentTitle;
TextView assignmentDate;
// if theres no view yet created on the screen, create one
if (convertView == null) {
convertView = inflater.inflate(R.layout.assignment_row, null);
// give the views their respective ID's
assignmentTitle = (TextView) convertView
.findViewById(R.id.assignment_row_title);
assignmentDate = (TextView) convertView
.findViewById(R.id.assignment_row_date);
// set the tag so we can just use the viewHolder instead of calling
// findViewById over. It saves memory
convertView.setTag(new assignmentViewHolder(assignmentTitle,
assignmentDate));
}
// this gets called when the user scrolls down or up the screen and the
// adapter
// wants to maximize efficiency by just calling the viewHolder instead
// of findViewById
else {
assignmentViewHolder viewHolder = (assignmentViewHolder) convertView
.getTag();
assignmentTitle = viewHolder.getTitle();
assignmentDate = viewHolder.getDate();
}
// down here is where you set the values for all your views/objects
// such as Buttons or textViews.
assignmentTitle.setText(Statics.allAssignments
.get(Statics.mainPageListPosition).get(position).getTitle());
assignmentDate.setText(Statics.allAssignments
.get(Statics.mainPageListPosition).get(position).getDate_due());
return convertView;
}
}
编辑:最近发现,我的哈希表将我发送给它的每个值都放在每个可用的位置,哈哈。我所做的是,当用户单击主页上的某个位置时,它会保存该位置并使用它来存储他们在哈希表中该位置保存的数据。 Temp 是一个 arrayList,其中用户保存的数据以这种格式存储:
{数字,字符串,数字,字符串} 其中数字是哈希表中我要存储字符串的位置。
这里是我将数据保存到哈希表的地方。在我看来一切都很好,也许我盯着它看得太久了@.@
for (int i = 0; i < temp.size(); i++) {
if (isInteger(temp.get(i))) {
currentAssignment.setTitle(temp.get(i + 1));
//currentAssignment.setDate_due(temp.get(i + 2));
currentAssignmentList.add(index, currentAssignment);
index++;
Statics.allAssignments.put(Integer.parseInt(temp.get(i)), currentAssignmentList);
//Statics.allAssignments.get(Integer.parseInt(temp.get(i))).add(currentAssignment);
currentAssignment = new Assignment();
//Toast.makeText(context, "Called" + Integer.toString(i), Toast.LENGTH_SHORT).show();
}
}
最佳答案
您在何处设置 ArrayAdapter 上的项目列表?我认为您应该使用 data
构造函数参数,与 addAll(data)
一起使用,或者在调用 super()
时使用。请注意,您目前在 getView()
中忽略此数据,而是使用您的静态数据。在 getView()
中,一旦您在父类(super class) ArrayAdapter 中正确设置了项目,您应该使用 Assignment a = getItem(position)
并从此对象而不是您的对象设置字段静力学。
例如在构造函数中...
super(context, R.id.assignment_row_title, R.id.assignment_row_date, data);
然后在 getView()...
Assignment a = getItem(position);
assignmentTitle.setText(a.getTitle());
assignmentDate.setText(a.getDate_due());
这当然假设您作为 data
传入的列表是正确的。希望一旦您的代码只查看一个项目列表,您就可以更轻松地验证此列表是否正确。
编辑:
在您的第二段代码中,您在哪里为每个哈希表键创建一个新的 currentAssignmentList
?如果您将相同的对象分配给哈希表的所有条目,那么它们都将包含相同的列表。
关于android - listView 显示所有数据,而不仅仅是我指定的数据,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/12995997/