如何使用Model Class更新SQLite表中的行？

Question

我是Android编程新手。我一直坚持这个问题，我想找到解决方案，通过其他问题和代码示例，似乎没有什么似乎与我创建这个应用程序的方法一致，作为一个初学者我不得不承认我完全失去了。我的词汇中没有很多技巧，所以我很难找到我想要的东西，希望有人可以帮我指出正确的方向。我正在尝试更新teams表格中的一个单独行，其中包含id，team_name和image，其中包含位于用户设备上的图片的文件路径。

团队表数据库设计

id  | team_name  | image
-------------------------
    |            |      

以下是我用来更新行的方法

updateTeam方法

public int updateTeam(Team team) {

 //get reference to writable DB
 SQLiteDatabase db = this.getWritableDatabase();

 //create ContentValues to add key "column"/value
 ContentValues values = new ContentValues();
 values.put("team_name", team.getTeamName()); // get team_name
 values.put("path", team.getPath()); // get image

 //updating row
 int i = db.update(TEAMS_TABLE, //table
  values, // column/value
  ID + " = ?", // selections
  new String[] {
   String.valueOf(team.getId())
  }); //selection args

 //close
 db.close();

 //return
 return i;
}

团队课

public class Team {
 String team_name, path, league_name;
 int id, league_id, points;

 public Team(int keyId, String team_name, String path,
  int points, String league_name) {
  this.id = keyId;
  this.team_name = team_name;
  this.path = path;
  this.points = points;
  this.league_name = league_name;
 }

 public Team(int keyId, String team_name, String path) {
  this.id = keyId;
  this.team_name = team_name;
  this.path = path;
 }

 public Team() {}

 public Team(int keyId) {
  this.id = keyId;

 }

 public int getId() {
  return id;
 }

 public void setId(int keyId) {
  this.id = keyId;
 }


 public int getLeagueId() {
  return league_id;
 }


 public String getTeamName() {
  return team_name;
 }

 public String getLeagueName() {
  return league_name;
 }

 public void setLeagueName(String league_name) {
  this.league_name = league_name;
 }

 public int getPoints() {
  return points;
 }

 public void setPoints(int points) {
  this.points = points;
 }


 public void setTeamName(String team_name) {
  this.team_name = team_name;
 }

 public void setLeague_id(int league_id) {
  this.league_id = league_id;
 }

 public void setPath(String path) {
  this.path = path;
 }

 public String getPath() {
  return path;
 }
}

TeamImageAdapter Class

public class TeamImageAdapter extends ArrayAdapter < Team > {

 Context context;
 int layoutResourceId;
 ArrayList < Team > data = new ArrayList < Team > ();

 public TeamImageAdapter(Context context, int layoutResourceId, ArrayList < Team > data) {
  super(context, layoutResourceId, data);
  this.layoutResourceId = layoutResourceId;
  this.context = context;
  this.data = data;
 }
 private final int THUMBSIZE = 200;

 /**
  * applying ViewHolder pattern to speed up ListView, smoother and faster
  * item loading by caching view in A ViewHolder object
  */
 private static class ViewHolder {
  ImageView imgIcon;
  TextView teamId, teamName, leagueName, points;
 }

 public View getView(int position, View convertView, ViewGroup parent) {
  View row = convertView;
  ViewHolder holder = null;
  if (row == null) {
   LayoutInflater inflater = ((Activity) context).getLayoutInflater();
   row = inflater.inflate(layoutResourceId, parent, false);
   holder = new ViewHolder();
   holder.teamId = (TextView) row.findViewById(R.id.txtTeamId);
   holder.teamName = (TextView) row.findViewById(R.id.txtTeamName);
   holder.leagueName = (TextView) row.findViewById(R.id.txtLeagueName);
   holder.points = (TextView) row.findViewById(R.id.txtPoints);
   holder.imgIcon = (ImageView) row.findViewById(R.id.item_img_icon);
   row.setTag(holder);
  } else {
   holder = (ViewHolder) row.getTag();
  }
  Team team = data.get(position);
  holder.teamId.setText(String.valueOf(team.id));
  holder.teamName.setText(team.team_name);
  holder.leagueName.setText(team.league_name);
  holder.points.setText("Points: " + String.valueOf(team.points));
  //convert string to bitmap and set to thumbsize
  holder.imgIcon.setImageBitmap(ThumbnailUtils
   .extractThumbnail(BitmapFactory.decodeFile(team.getPath()),
    THUMBSIZE, THUMBSIZE));
  return row;
 }
}

DisplayTeam类（显示ListView中的所有团队）

public class DisplayTeam extends AppCompatActivity {
 ArrayList < Team > imageArry = new ArrayList < Team > ();
 TeamImageAdapter adapter;

 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.display_team);

  DatabaseHelper myDb = new DatabaseHelper(this);

  // Reading all teams from database
  List < Team > team = myDb.getAllTeams();
  for (Team tm: team) {
   String log = "ID:" + tm.getId() + " Team Name: " + tm.getTeamName() + " ,Image: " + tm.getPath() + " ,Points: " + tm.getPoints() + " ,League Name: " + tm.getLeagueName();

   // Writing teams to log
   Log.d("Result: ", log);
   //add teams data in arrayList
   imageArry.add(tm);
  }
  adapter = new TeamImageAdapter(this, R.layout.teams_list,
   imageArry);
  final ListView dataList = (ListView) findViewById(R.id.main_list_view);
  dataList.setAdapter(adapter);

  dataList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
   @Override
   public void onItemClick(AdapterView < ? > parent, View view, int position, long id) {

    TextView tid = (TextView) view.findViewById(R.id.txtTeamId);
    Long teamId = Long.valueOf(tid.getText().toString());
   }
  });
 }
} 

我想要它，以便当我点击ListView时会出现一个弹出窗口，其中包含一个显示当前团队team_name的EditText。我只是不确定它的名称或我如何执行此操作。有点像

以及更新代码可能会是什么样子。我并不是真的期待一个完整的代码答案，而只是一个正确的方向，一步一步的教程将是非常有帮助的。非常感谢任何有用的人。

Answer 1

当您更新数据库中的行时，您必须更新适配器。

因为当您将适配器设置为列表时，它会从数据库中获取记录。但是在更新行之后，您不会改变适配器值。

所以在List < Team > team;中声明Activity为全局变量，并在onCreate方法中对其进行初始化。

将新值设置为适配器并通知OnItemClickListener方法

中更改的数据集

dataList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
    @Override
    public void onItemClick(AdapterView < ? > parent, View view, int position, long id) {
        Team teamToUpdate = team.get(position);
        int status = updateTeam(teamToUpdate);
        if(status > 0) {
            // update success
            // change the adapter values here
            imageArry.clear();
            team = myDb.getAllTeams();
            for (Team tm: team) {
                String log = "ID:" + tm.getId() + " Team Name: " + tm.getTeamName() +
                    " ,Image: " + tm.getPath() + " ,Points: " + tm.getPoints() +
                    " ,League Name: " + tm.getLeagueName();
                // Writing teams to log
                Log.d("Result: ", log);
                //add teams data in arrayList
                imageArry.add(tm);
            }
            adapter.notifyDataSetChanged();
        } else {
            // failed to update
            // check the reason
        }
    }
});

希望它会有所帮助。

Answer 2

/*public int getId() {
  return id;
 }
*/

db.update(TEAMS_TABLE, values,
  ID + " = ?", new String[] {
   Integer.toString(team.getId())
  });