我无法从ListView中的ArrayList中显示正确的字符串。
我的数组（m_aDataList）如下：
m_aDataList {ArrayList}
{...}0
m_cText = "R;21;9;River Street 2;12154;;1;.......
m_cTimeStamp = 1556553367492
m_nID = 7
m_nStatus = 0
m_nType = 10002
{...}1
....
这是我当前尝试在ListView中显示ArrayList的方式：
ArrayAdapter<Message> tuAdapter;
MessageManager tu = new MessageManager();
ArrayList<Message> list = tu.getMessageData();
tuAdapter = new ArrayAdapter<Message>(this, android.R.layout.simple_list_item_1, list);
lvOrders.setAdapter(tuAdapter);
它在技术上有效，并且在我的ListView中添加了类似的内容：
de.telematik.testapp.entities.Message@232d9c76
但是我想做的是，仅在m_nType == 10002的地方显示消息，并在ListView中这样显示它们：
Order: 12154 (order number from m_cText)
检查m_nType是否= 10002或10000都不是问题。但是，如何从字符串m_cText中获取订单号，然后将其显示在ListView中呢？
无论如何，谢谢您的帮助。
答案 0 :(得分：0)
您正在使用基本的默认列表适配器，但是正在向其传递对象数组（消息）。为了控制列表中显示的内容，您将需要创建自己的自定义适配器类，该类将扩展（可能是基本适配器）标准适配器类之一。您将以类似于将列表传递到简单列表适配器的方式来调用它。这是一个示例自定义列表适配器：
ClaimListAdapter.java
package com.mycompany.myapp.adapter;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import com.mycompany.myapp.R;
import com.mycompany.myapp.ClaimListFragment;
import com.mycompany.myapp.model.ClaimItem;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.View.OnClickListener;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.TextView;
public class ClaimListAdapter extends BaseAdapter {
private Context context;
private ArrayList<ClaimItem> claimItems;
ClaimListFragment fragment;
public ClaimListAdapter(ClaimListFragment fragment, Context context, ArrayList<ClaimItem> claimItems){
this.context = context;
this.claimItems = claimItems;
this.fragment = fragment;
}
@Override
public int getCount() {
return claimItems.size();
}
@Override
public Object getItem(int position) {
return claimItems.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@SuppressLint("InflateParams")
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// This method gets called for every item in the list when it is about to be displayed in the list
// This helps you get a reference to the layout of the list item
if (convertView == null) {
LayoutInflater mInflater = (LayoutInflater)
context.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
convertView = mInflater.inflate(R.layout.claim_list_item, null);
}
// If you have a button that you want to perform some function, such as delete, and then call
// a method back in the parent to update the items in the array, this is one way to do it
Button btnDelete = (Button) convertView.findViewById(R.id.claim_delete_in_list);
// Save the position of the item in the list, so, you know which item was clicked
btnDelete.setTag(position);
btnDelete.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Integer position = (Integer)v.getTag();
// Call this method which is back in the parent, which in this case is a fragment, but could be an Activity
fragment.deleteItemList(position);
}
});
btnDelete.setVisibility(View.GONE);
// Here you get a reference to the various TextViews in your layout
TextView txtTitle = (TextView) convertView.findViewById(R.id.claim_title);
TextView txtStatus = (TextView) convertView.findViewById(R.id.claim_status);
TextView txtDate = (TextView) convertView.findViewById(R.id.claim_date);
TextView txtDistance = (TextView) convertView.findViewById(R.id.claim_distance);
TextView txtAmount = (TextView) convertView.findViewById(R.id.claim_amount);
// Here you get the various strings out of your object for display
String claim_title = claimItems.get(position).getDocumentID();
if (claim_title == null) {
claim_title = "";
}
String claim_status = claimItems.get(position).getClaimStatus();
String claim_date = claimItems.get(position).getClaimDate();
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");
Date date = null;
try {
date = (Date) dateFormat.parse(claim_date);
dateFormat = new SimpleDateFormat("M/d/yyyy");
String formattedDate = dateFormat.format(date);
txtDate.setText(formattedDate);
} catch (ParseException e) {
e.printStackTrace();
}
double total_miles = claimItems.get(position).getTotalMiles();
double total_amount = claimItems.get(position).getTotalAmount();
// Here you set the values in the TextView for display
txtTitle.setText(claim_title);
txtStatus.setText(claim_status);
txtDistance.setText("" + total_miles + "mi");
txtAmount.setText("$" + total_amount);
return convertView;
}
}
或者，您可以创建一个仅包含消息数组中的订单号的字符串数组，然后将该数组而不是消息数组传递给列表适配器。