sqlite 行 ID 与列表视图不匹配 - ANDROID

Posted 2023-05-07

【中文标题】sqlite 行 ID 与列表视图不匹配 - ANDROID

【英文标题】：sqlite row ids not matching listview - ANDROID

【发布时间】：2015-03-08 07:18:38

【问题描述】：

这可能是一个蹩脚的问题，但我是初学者，似乎不了解我的应用程序的行为。

我有一个 SQLite 数据库，并且在主要活动中有一个列表视图。 在列表视图中，我显示列表编号（行 ID）和其他详细信息。 按下列表项后，会打开一个新活动，在文本视图中显示详细信息，并有 2 个用于删除和同步的图像按钮。

在我删除任何条目之前，该应用程序运行良好。

一旦我删除任何条目，列表视图上的行 ID 似乎不会更新行号。 （如果我删除第一行，顶部的行显示 2（应该是 1，因为它是新的第一行）。

但是，当我显示记录的详细信息时，它是正确的。 （列表中的第二项显示第 2 行）

此外，当我按下列表视图中的位置与我之前删除的位置相同的项目时，应用程序崩溃（假设我删除第一个条目，之后每当我单击列表视图上的第一个项目时显示它应用程序崩溃）

我在应用程序崩溃时遇到错误：

java.lang.RuntimeException: Unable to start activity ComponentInfocom.example.aakashmaroti.fillup/com.example.aakashmaroti.fillup.DisplayDetails: android.database.CursorIndexOutOfBoundsException: Index 0 requested, with a size of 0

我的主要活动

package com.example.aakashmaroti.fillup;

import android.app.Dialog;
import android.content.Context;
import android.content.Intent;
import android.content.res.Resources;
import android.database.Cursor;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
import android.widget.TextView;
import android.widget.Toast;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;


public class StartScreen extends ActionBarActivity implements View.OnClickListener 


    FavoriteList favList = new FavoriteList();

    TextView rid,ts,sd;
    ListView lv;
    Context context=this;
    Find db=new Find(this);
    List<FavoriteList> favoriteList;
    LinearLayout layout;

    @Override
    protected void onCreate(Bundle savedInstanceState)
    
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_start_screen);
        Button b = (Button) findViewById(R.id.AddButton);
        b.setOnClickListener(this);
        lv = (ListView) findViewById(R.id.listview);
        try
        
            populateListViewFromDatabase();
         catch (Exception e)
        
            Toast.makeText(getApplicationContext(), "Oops there has been an error "+e.toString()+"", Toast.LENGTH_LONG).show();
            e.printStackTrace();
        

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


    


    @Override
    public void onResume()
    
        super.onResume();
        try
        
            populateListViewFromDatabase();
         catch (Exception e)
        
            Toast.makeText(getApplicationContext(), "Oops there has been an error "+e.toString()+"", Toast.LENGTH_LONG).show();
            e.printStackTrace();
        

    

    @Override
    public boolean onCreateOptionsMenu(Menu menu) 
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_start_screen, menu);
        return true;
    

    @Override
    public boolean onOptionsItemSelected(MenuItem item) 
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) 
            return true;
        

        return super.onOptionsItemSelected(item);
    

    @Override
    public void onClick(View v) 

        switch (v.getId())
        
            case R.id.AddButton:
                startActivity(new Intent(this,Form.class));
                break;

            default: break;
        
    

    public void populateListViewFromDatabase()throws Exception
    
        Find info=new Find(this);
        try
        
            info.open();
            SimpleCursorAdapter myCursorAdapter;
            myCursorAdapter = info.listUp();
            lv.setAdapter(myCursorAdapter);
            info.close();

         catch (SQLException e)
        
            e.printStackTrace();
            Toast.makeText(getApplicationContext(), "Oops there has been an error "+e.toString()+"", Toast.LENGTH_LONG).show();
        
    
    public void showsDialog(int pos)
    

        pos++;
        String s = "";
        s += pos;
        Intent i = new Intent(getApplicationContext(), DisplayDetails.class);
        i.putExtra("position", s);
        startActivity(i);

        try
        
            populateListViewFromDatabase();
         catch (Exception e)
        
            e.printStackTrace();
        
    

sqlite数据库管理类

package com.example.aakashmaroti.fillup;

import android.app.Dialog;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.graphics.Bitmap;
import android.graphics.Color;
import android.view.View;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
import android.widget.TextView;
import android.widget.Toast;

import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

/**
 * Created by Aakash Maroti on 28-Dec-14.
 */
public class Find

    public static final String KEY_ROWID = "_id";
    public static final String KEY_TIMESTAMP= "time_stamp";
    public static final String KEY_IS_SYNCED = "sync";
    public static final String KEY_NameOfCompany="name_of_company";



    private static final String DATABASE_NAME = "FillUpFormsDB";
    private static final String DATABASE_TABLE = "FillUpFormsTable";
    private static final int DATABASE_VERSION = 1;

    private DbHelper ourHelper;
    private final Context ourContext;
    private SQLiteDatabase ourDatabase;




    private static class DbHelper extends SQLiteOpenHelper
    

        public DbHelper(Context context)
        
            super(context,DATABASE_NAME,null,DATABASE_VERSION);
        



        @Override
        public void onCreate(SQLiteDatabase db)
        
            db.execSQL("CREATE TABLE " + DATABASE_TABLE + " (" +
                    KEY_ROWID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
                            KEY_IS_SYNCED +" TEXT NOT NULL, " +
                            KEY_TIMESTAMP +" TEXT NOT NULL, " +
                            KEY_NameOfCompany+" TEXT NOT NULL);"
            );
        

        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)
        
            db.execSQL("DROP TABLE IF EXISTS "+DATABASE_TABLE);
            onCreate(db);
             

      


    public Find(Context c)
    
        ourContext = c;
    

    public Find open()throws SQLException
    
        ourHelper = new DbHelper(ourContext);
        ourDatabase=ourHelper.getWritableDatabase();
        return this;
    

    public void close()
    
        ourHelper.close();
    


    public long createEntry(String isSynced, String timeStamp, String nameOfCompany)
    
        ContentValues cv=new ContentValues();
        cv.put(KEY_IS_SYNCED,isSynced);
        cv.put(KEY_TIMESTAMP,timeStamp);
        cv.put(KEY_NameOfCompany,nameOfCompany);        

        return ourDatabase.insert(DATABASE_TABLE,null,cv);

    

    public SimpleCursorAdapter listUp()
    

        String columns[]=new String[]KEY_ROWID,KEY_TIMESTAMP,KEY_IS_SYNCED;
        Cursor c= ourDatabase.query(DATABASE_TABLE,columns,null,null,null,null,null);
        int toViewIDs[] = new int[]R.id.rowno,R.id.timestamp,R.id.syncdetails;
        SimpleCursorAdapter CursorAdapter;
        CursorAdapter = new SimpleCursorAdapter(ourContext,R.layout.design_row,c,columns,toViewIDs,0);
        return CursorAdapter;
    

    public String getDetails(long row)
    
        String columns[]=new String[] KEY_ROWID, KEY_IS_SYNCED, KEY_TIMESTAMP,KEY_NameOfCompany;
        String result="";        
        Cursor c= ourDatabase.query(DATABASE_TABLE,columns,KEY_ROWID+"="+row,null,null,null,null);
        if(c!=null)
        
            String r;
            c.moveToFirst();
            r="\nRecord No. : "+c.getString(0)+"\n\nSync Status:"+c.getString(1)+"\n\nTime of Creation:\n"+c.getString(2)+"\n\nName of Company:\n"+c.getString(3);
            return r;
        

        return result;
    

    public void DeleteRow(int pos)
    
        ourDatabase.delete(DATABASE_TABLE,KEY_ROWID+"="+pos,null);
    

显示结果的新活动的类。

package com.example.aakashmaroti.fillup;

import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.ImageButton;
import android.widget.TextView;
import android.widget.Toast;

import java.sql.SQLException;


public class DisplayDetails extends ActionBarActivity implements View.OnClickListener



    ImageButton ibSync;
    ImageButton ibDelete;
    TextView DispDetails;
    int pos;
    @Override
    protected void onCreate(Bundle savedInstanceState)
    
        super.onCreate(savedInstanceState);
        Bundle extras = getIntent().getExtras();

        String value="1";
        if (extras != null) 
           value = extras.getString("position");
        
        pos=Integer.parseInt(value);
        setContentView(R.layout.activity_display_details);
        ibSync=(ImageButton)findViewById(R.id.imageButtonSync);
        ibDelete=(ImageButton)findViewById(R.id.imageButtonDelete);
        DispDetails = (TextView)findViewById(R.id.textViewDisplayDetails);
        String s="";

        ibSync.setOnClickListener(this);
        ibDelete.setOnClickListener(this);

        Find info1=new Find(this);
        try
        
            info1.open();
            s=info1.getDetails(pos);
            info1.close();

         catch (SQLException e)
        
            e.printStackTrace();
            Toast.makeText(getApplicationContext(), "Oops there has been an error "+e.toString()+"", Toast.LENGTH_LONG).show();
        
        DispDetails.setText(s);

    


    @Override
    public boolean onCreateOptionsMenu(Menu menu)
    
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_display_details, menu);
        return true;
    

    @Override
    public boolean onOptionsItemSelected(MenuItem item)
    
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings)
        
            return true;
        

        return super.onOptionsItemSelected(item);
    

    @Override
    public void onClick(View v)
    
        if(v.getId()==R.id.imageButtonSync)
        
            Toast.makeText(getApplicationContext(), "This functionality has not yet been added", Toast.LENGTH_LONG).show();
        
        if(v.getId()==R.id.imageButtonDelete)
           Find info1=new Find(this);
            try
            
                info1.open();
                info1.DeleteRow(pos);
                info1.close();

             catch (SQLException e)
            
                e.printStackTrace();
                Toast.makeText(getApplicationContext(), "Oops there has been an error "+e.toString()+"", Toast.LENGTH_LONG).show();
            


            Toast.makeText(getApplicationContext(), "This record has been successfully deleted", Toast.LENGTH_LONG).show();
            cancel();
        
    

    public void cancel()
    
        this.finish();
        return;
    

列表视图中单行的xml文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:layout_
              android:layout_>


    <TextView
        android:layout_
        android:layout_
        android:text=""
        android:textStyle="bold"
        android:clickable="true"
        android:id="@+id/rowno"/>   

    <TextView
        android:layout_
        android:layout_
        android:textAppearance="?android:attr/textAppearanceMedium"
        android:text=""
        android:clickable="true"
        android:id="@+id/timestamp"/>

    <TextView
        android:layout_
        android:layout_
        android:textStyle="bold"
        android:text=""
        android:clickable="true"
        android:id="@+id/syncdetails"/>

</LinearLayout>

任何帮助将不胜感激。

提前致谢。

【参考方案1】：

因为你传递的是列表视图项的位置，它应该是数据库行id。

改变

@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id)

    showsDialog(position);

到

@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id)

    TextView pos = (TextView) view.findViewById(R.id.rowno);
    showsDialog(pos.getText().toString());

你也说过

Once I delete any entry the row id on the listview doesn't seem to update the row number. (if i delete the first row, the row on top shows 2(should be 1, as it is the new first row)).

但它不会因为这是数据库行 id 而不是列表视图位置。

【讨论】：

非常感谢！它就像一个魅力！还有一种方法可以显示项目位置而不是行 id 吗？因为删除行 id 会产生错误。再次感谢！

如果你想显示列表视图项的位置而不是行 ID，那么我猜你将不得不使用自定义适配器。

【参考方案2】：

您只能在 onResume 或 onCreate 中获取您的光标。因此，尽管数据发生了变化，但您的光标保持不变。查看 LoaderManager 类。