Android Studio 数组值到 TextView

Question

我已经按照 Wintech 的教程建立了与 MS SQL 数据库的连接，我的结果是在调试器中得到 200，所以我知道它连接成功。我的问题是我无法在应用程序中显示查询结果...

activity_main.xml:

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.pmatthews.appointmentcreator.MainActivity">

<LinearLayout
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="@drawable/bg"

    android:orientation="vertical">

    <ImageView
        android:id="@+id/imageView"

        android:layout_width="match_parent"
        android:layout_height="wrap_content"

        android:onClick="openWebpage"
        android:src="@drawable/logo" />

    <ScrollView

        android:id="@+id/scroll"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content">

        <LinearLayout
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical">

            <LinearLayout
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:layout_marginTop="15dp"
                android:orientation="horizontal">

                <TextView
                    android:layout_width="0dp"

                    android:layout_height="wrap_content"
                    android:layout_marginLeft="15dp"

                    android:layout_marginTop="5dp"
                    android:layout_weight="1"
                    android:text="Appointment Number:"
                    android:textColor="#000000" />


                <EditText
                    android:id="@+id/ApptNumView"

                    android:layout_width="0dp"
                    android:layout_height="wrap_content"

                    android:layout_marginRight="15dp"
                    android:layout_marginTop="5dp"
                    android:layout_weight="1" />

                <ImageButton
                    android:id="@+id/refreshButton"

                    android:layout_width="30dp"
                    android:layout_height="30dp"
                    android:background="@drawable/refresh"
                    android:onClick="testConnection" />
            </LinearLayout>

            <LinearLayout
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:layout_marginTop="30dp"

                android:orientation="horizontal">

                <TextView
                    android:id="@+id/textView"

                    android:layout_width="0dp"

                    android:layout_height="wrap_content"
                    android:layout_marginLeft="15dp"

                    android:layout_marginTop="5dp"
                    android:layout_weight="1"
                    android:text="Material Owner Number:"
                    android:textColor="#000000" />

                <TextView
                    android:id="@+id/MatOwnNumView"

                    android:layout_width="0dp"
                    android:layout_height="wrap_content"

                    android:layout_marginRight="15dp"
                    android:layout_marginTop="5dp"
                    android:layout_weight="1" />
            </LinearLayout>

            <LinearLayout
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:layout_marginTop="30dp"

                android:orientation="horizontal">

                <TextView
                    android:layout_width="0dp"

                    android:layout_height="wrap_content"
                    android:layout_marginLeft="15dp"

                    android:layout_marginTop="5dp"
                    android:layout_weight="6.5"
                    android:text="Carrier Number:"
                    android:textColor="#000000" />

                <TextView
                    android:id="@+id/CarrNumView"

                    android:layout_width="0dp"
                    android:layout_height="wrap_content"

                    android:layout_marginRight="15dp"
                    android:layout_marginTop="5dp"
                    android:layout_weight="4" />

                <ImageButton
                    android:id="@+id/CarrNumButton"

                    android:layout_width="30dp"

                    android:layout_height="30dp"
                    android:background="@drawable/searchicon"


                    />
            </LinearLayout>

            <LinearLayout
                android:layout_width="fill_parent"
                android:layout_height="82dp"
                android:orientation="horizontal">

                <TextView
                    android:layout_width="0dp"

                    android:layout_height="wrap_content"
                    android:layout_marginLeft="15dp"


                    android:layout_marginTop="5dp"
                    android:layout_weight="1"
                    android:text="Purchase Order Number:"
                    android:textColor="#000000" />

                <EditText
                    android:id="@+id/PONInput"

                    android:layout_width="0dp"
                    android:layout_height="wrap_content"
                    android:layout_marginRight="15dp"
                    android:layout_marginTop="5dp"
                    android:layout_weight="1" />
            </LinearLayout>

            <LinearLayout
                android:layout_width="fill_parent"
                android:layout_height="82dp"
                android:orientation="horizontal">

                <TextView
                    android:layout_width="0dp"

                    android:layout_height="wrap_content"
                    android:layout_marginLeft="15dp"


                    android:layout_marginTop="5dp"
                    android:layout_weight="1"
                    android:text="Release Number:"
                    android:textColor="#000000" />

                <EditText
                    android:id="@+id/RelNumInput"

                    android:layout_width="0dp"
                    android:layout_height="wrap_content"
                    android:layout_marginRight="15dp"
                    android:layout_marginTop="5dp"
                    android:layout_weight="1" />
            </LinearLayout>

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content">

                <TextView
                    android:layout_width="0dp"


                    android:layout_height="wrap_content"
                    android:layout_marginLeft="15dp"
                    android:layout_marginTop="5dp"

                    android:layout_weight="1"
                    android:text="Rail Car No:"
                    android:textColor="#000000" />

                <EditText
                    android:id="@+id/RailCarInput"

                    android:layout_width="0dp"
                    android:layout_height="wrap_content"

                    android:layout_marginRight="15dp"

                    android:layout_marginTop="5dp"
                    android:layout_weight="1" />
            </LinearLayout>


            <TextView
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"

                android:layout_marginLeft="5dp"
                android:layout_marginRight="5dp"

                android:text="Actuals"

                android:textColor="#000000"
                android:textSize="30sp" />

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content">

                <CheckBox
                    android:id="@+id/truckArrivedBox"

                    android:layout_width="0dp"
                    android:layout_height="wrap_content"
                    android:layout_marginLeft="15dp"

                    android:layout_weight="1" />

                <TextView
                    android:layout_width="0dp"

                    android:layout_height="wrap_content"
                    android:layout_weight="7"

                    android:text="Truck has Arrived"

                    android:textColor="#000000" />
            </LinearLayout>

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:orientation="vertical">

                <LinearLayout
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:orientation="horizontal">

                    <TextView
                        android:layout_width="0dp"

                        android:layout_height="wrap_content"

                        android:layout_marginLeft="15dp"
                        android:layout_marginTop="20dp"

                        android:layout_weight="1"
                        android:text="Bill Lading No In:"

                        android:textColor="#000000" />

                    <EditText
                        android:id="@+id/billNumInput"

                        android:layout_width="0dp"
                        android:layout_height="wrap_content"

                        android:layout_marginRight="15dp"
                        android:layout_marginTop="20dp"
                        android:layout_weight="1" />
                </LinearLayout>

                <LinearLayout
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:orientation="vertical">

                    <TextView
                        android:layout_width="wrap_content"

                        android:layout_height="wrap_content"

                        android:layout_marginLeft="15dp"
                        android:layout_marginTop="40dp"

                        android:layout_weight="1"
                        android:text="Arrival Date:"
                        android:textColor="#000000" />

                    <DatePicker
                        android:id="@+id/arrivalDateInput"
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"

                        android:layout_marginTop="20dp"
                        android:datePickerMode="calendar"


                        />

                </LinearLayout>

                <LinearLayout
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:orientation="vertical">

                    <TextView
                        android:layout_width="fill_parent"

                        android:layout_height="wrap_content"

                        android:layout_marginLeft="15dp"
                        android:layout_marginTop="20dp"

                        android:layout_weight="1"

                        android:text="Arrival Time:"
                        android:textColor="#000000" />

                    <TimePicker
                        android:id="@+id/arrivalTimeInput"

                        android:layout_width="fill_parent"

                        android:layout_height="wrap_content"
                        android:layout_marginRight="15dp"

                        android:layout_marginTop="20dp"
                        android:layout_weight="1"
                        android:timePickerMode="spinner" />


                </LinearLayout>
            </LinearLayout>

            <LinearLayout

                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:orientation="vertical">

                <Button
                    android:id="@+id/recieveButton"

                    android:layout_width="fill_parent"
                    android:layout_height="wrap_content"
                    android:layout_marginLeft="15dp"
                    android:layout_marginRight="15dp"
                    android:text="Recieve Inventory" />

                <LinearLayout
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:orientation="horizontal">

                    <Button
                        android:id="@+id/saveButton"

                        android:layout_width="0dp"

                        android:layout_height="wrap_content"
                        android:layout_marginLeft="15dp"

                        android:layout_weight="1"
                        android:text="Save"

                        />

                    <Button
                        android:id="@+id/cancelButton"

                        android:layout_width="0dp"
                        android:layout_height="wrap_content"
                        android:layout_marginRight="15dp"

                        android:layout_weight="1"
                        android:text="Cancel" />
                </LinearLayout>

            </LinearLayout>

            <ListView
                android:id="@+id/list"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"></ListView>

            <ListView
                android:id="@+id/listView"
                android:layout_width="match_parent"
                android:layout_height="wrap_content">

            </ListView>




            <TextView
                android:id="@+id/txtConNum"
                android:layout_width="fill_parent"
                android:layout_height="100dp"/>





        </LinearLayout>

    </ScrollView>

</LinearLayout>


</android.support.constraint.ConstraintLayout>

MainActivity.java:

package com.example.pandasai.project;

import android.app.Activity;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

import android.view.View;
import android.content.Intent;
import android.net.Uri;
import android.widget.AdapterView;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;


import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;

import java.util.ArrayList;
import java.util.HashMap;
import android.os.AsyncTask;
import android.widget.TableLayout;
import android.widget.TextView;
import android.widget.Toast;

import org.json.JSONArray;
import org.json.JSONObject;

import static com.example.pandasai.project.R.id.txtConNum;


public class MainActivity extends AppCompatActivity {

    ArrayList<HashMap<String, String>> conNumList;
    ListAdapter adapter;




@Override
    protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);


    conNumList = new ArrayList<HashMap<String, String>>();
    ListView list = (ListView) findViewById(R.id.list);
    new GetConNum(MainActivity.this, 
list).execute("http://xxx.xxx.xxx.xxx/LocalAppTest/Service1.svc/GetConNum");
}
class GetConNum extends AsyncTask<String, Void, String>{

String status = null;
Activity context;
ListView listView;
public GetConNum(Activity context, ListView listView){
    this.context = context;
    this.listView = listView;
}
protected void onPreExecute(){

}
protected String doInBackground(String... connUrl){
    HttpURLConnection conn = null;
    BufferedReader reader;

    try{
        final URL url = new URL(connUrl[0]);
        conn = (HttpURLConnection) url.openConnection();
        conn.addRequestProperty("Content-Type", "application/json; 
charset=utf-8");
        conn.setRequestMethod("GET");
        int result = conn.getResponseCode();
        if(result == 200){

            InputStream in = new BufferedInputStream(conn.getInputStream());
            reader = new BufferedReader(new InputStreamReader(in));
            StringBuilder sb = new StringBuilder();
            String line = null;

            while ((line = reader.readLine()) != null){
                status = line;
            }

        }

    }catch(Exception ex){

    }
    return status;
    }
    protected void onPostExecute(String result){
    super.onPostExecute(result);

    if(result != null){
        try{

            ArrayList<String> stringArrayList = new ArrayList<String>();
            JSONArray jsonArray = new JSONArray(result);
            for(int i=0; i<jsonArray.length(); i++){
                JSONObject object = jsonArray.getJSONObject(i);
                String ControlNumber = object.getString("ControlNumber");

                HashMap<String, String> itemList = new HashMap<String, 
String>();
                itemList.put("ControlNumber", ControlNumber);

                conNumList.add(itemList);


            }
            adapter = new SimpleAdapter(MainActivity.this, conNumList, 
R.layout.activity_main, new String[]{"ControlNumber"}, new int[]
{txtConNum});
             ((AdapterView<ListAdapter>) listView).setAdapter(adapter);


        }catch(Exception ex){
            ex.printStackTrace();
        }
    }else{
        Toast.makeText(MainActivity.this, "Failed to connect.", 
Toast.LENGTH_LONG).show();
    }
}
}





public void openWebpage(View view){
    Uri webLink = Uri.parse("http://examplesite.com");
    Intent webLinkIntent = new Intent(Intent.ACTION_VIEW, webLink);

    startActivity(webLinkIntent);
}


}

我没有收到任何我知道的错误，它只是没有按照 Wintech 教程中的方式执行。我不确定我错过了什么。我故意遗漏了 POST 位，因为我不打算稍后再写入数据库。至于现在，我只是想获取在应用程序的 TextView 中显示的查询结果。

Wintech 的教程：

Android - SQL 服务器数据库连接（第 1 部分，创建 WCF Web 服务）

https://youtu.be/xnO9MbferQo

Android - SQL 服务器数据库连接（第 2 部分，获取和 Post 数据）

https://youtu.be/RLDIjrDRrU8

Answer 1

您正在替换最后一个 readline 输出，所以最后一行可能是 \n 字符。你应该更换

while ((line = reader.readLine()) != null){
                status = line;
            }

与

while ((line = reader.readLine()) != null){
                sb.append(line);
            }

..
return sb.toString()

编辑

protected String doInBackground(String... connUrl){
    HttpURLConnection conn = null;
    BufferedReader reader;
    StringBuilder sb;

    try{
        final URL url = new URL(connUrl[0]);
        conn = (HttpURLConnection) url.openConnection();
        conn.addRequestProperty("Content-Type", "application/json; 
charset=utf-8");
        conn.setRequestMethod("GET");
        int result = conn.getResponseCode();
        if(result == 200){

            InputStream in = new BufferedInputStream(conn.getInputStream());
            reader = new BufferedReader(new InputStreamReader(in));
            sb = new StringBuilder();
            String line = null;

            while ((line = reader.readLine()) != null){
                sb.append(line);
            }

        }

    }catch(Exception ex){

    }
    return sb.toString();
    }
    protected void onPostExecute(String result){
       super.onPostExecute(result);
       System.out.println(result);
    }

Answer 2

我仔细运行通过调试器，看到它正在将查询中的数据存储到 result。我在 ListView 中添加了一个 TextView，在 AsyncTask 中将其声明为 txtV，在 PostExecute 中我添加了 txtV.setText(result)

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