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我想填充SQLite數據庫的列表視圖，但類轉換異常。這是我的logcat：java.lang.classcastexception：java.util.ArrayList
05-26 09:03:40.376: E/AndroidRuntime(309): Caused by: java.lang.ClassCastException: java.util.ArrayList
05-26 09:03:40.376: E/AndroidRuntime(309): at com.example.packinfo.MainActivity.displayListview(MainActivity.java:58)
05-26 09:03:40.376: E/AndroidRuntime(309): at com.example.packinfo.MainActivity.onCreate(MainActivity.java:27)
05-26 09:03:40.376: E/AndroidRuntime(309): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
05-26 09:03:40.376: E/AndroidRuntime(309): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
這裏是我的代碼：
MainActivity.java：
DatabaseHandler.java：
package com.example.packinfo;
import java.util.ArrayList;
import java.util.List;
import com.example.packinfo.Package;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
public class DatabaseHandler extends SQLiteOpenHelper {
private static final int DATABASE_VERSION = 1;
private static final String DATABASE_NAME="Package_DB";
private static final String TABLE_PACKAGE = "Package";
private static final String KEY_PKG_ID= "pkgid";
private static final String KEY_PKG_TYPE= "pkgtyp";
private static final String KEY_PKG_NAME ="pkgname";
private static final String KEY_NO_OF_FREE_ITEMS= "nitems";
private static final String KEY_DURATION ="dur";
private static final String KEY_CHARGES ="charge";
public DatabaseHandler(Context context){
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
public void onCreate(SQLiteDatabase db){
String createPKGTABLE = "CREATE TABLE " + TABLE_PACKAGE + "("
+ KEY_PKG_ID + " TEXT PRIMARY KEY," + KEY_PKG_TYPE + " TEXT,"
+ KEY_PKG_NAME + " TEXT," + KEY_NO_OF_FREE_ITEMS + " INTEGER,"
+ KEY_DURATION + " INTEGER," + KEY_CHARGES + " INTEGER " + ")";
db.execSQL(createPKGTABLE);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
db.execSQL("DROP TABLE IF EXISTS"+ TABLE_PACKAGE);
onCreate(db);
}
public void addPackage(Package pkg)
{
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values= new ContentValues();
values.put(KEY_PKG_ID, pkg.getPKG_ID());
values.put(KEY_PKG_TYPE, pkg.getPKG_TYPE());
values.put(KEY_PKG_NAME, pkg.getPKG_NAME());
values.put(KEY_NO_OF_FREE_ITEMS, pkg.getPKG_ITEMS());
values.put(KEY_DURATION, pkg.getPKG_DURATION());
values.put(KEY_CHARGES, pkg.getPKG_CHARGES());
db.insert(TABLE_PACKAGE, null, values);
db.close();
}
public List<Package> getPackages()
{
List<Package> pkglist = new ArrayList<Package>();
String selectquery ="SELECT * FROM "+TABLE_PACKAGE;
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(selectquery, null);
if(cursor.moveToFirst())
{
do{
Package pkg =new Package();
pkg.setPKG_ID(cursor.getString(0));
pkg.setPKG_TYPE(cursor.getString(1));
pkg.setPKG_NAME(cursor.getString(2));
pkg.setPKG_ITEMS(Integer.parseInt(cursor.getString(3)));
pkg.setPKG_DUARTION(Integer.parseInt(cursor.getString(4)));
pkg.setPKG_CHARGES(Float.parseFloat(cursor.getString(5)));
pkglist.add(pkg);
}while(cursor.moveToNext());
}
return pkglist;
}
}
Package.java：
package com.example.packinfo;
public class Package {
String _PKG_ID;
String _PKG_TYPE;
String _PKG_NAME;
int _NO_OF_FREE_ITEMS;
int _DURATION;
float _CHARGES;
public Package(){}
public Package(String _PKG_ID,
String _PKG_TYPE,
String _PKG_NAME,
int _NO_OF_FREE_ITEMS,
int _DURATION,
float _CHARGES){
this._PKG_ID= _PKG_ID;
this._PKG_TYPE= _PKG_TYPE;
this._PKG_NAME = _PKG_NAME;
this._NO_OF_FREE_ITEMS = _NO_OF_FREE_ITEMS;
this._DURATION= _DURATION;
this._CHARGES = _CHARGES;
}
public Package(String pkgtyp,String pkgname, int nitems, int dur, float charge)
{
this._PKG_TYPE= pkgtyp;
this._PKG_NAME = pkgname;
this._NO_OF_FREE_ITEMS = nitems;
this._DURATION= dur;
this._CHARGES= charge;
}
public String getPKG_ID()
{
return this._PKG_ID;
}
public void setPKG_ID(String pkgid)
{
this._PKG_ID= pkgid;
}
public String getPKG_TYPE()
{
return this._PKG_TYPE;
}
public void setPKG_TYPE(String pkgtyp)
{
this._PKG_TYPE= pkgtyp;
}
public String getPKG_NAME()
{
return this._PKG_NAME;
}
public void setPKG_NAME(String pkgname)
{
this._PKG_NAME= pkgname;
}
public int getPKG_ITEMS()
{
return this._NO_OF_FREE_ITEMS;
}
public void setPKG_ITEMS(int nitems)
{
this._NO_OF_FREE_ITEMS= nitems;
}
public int getPKG_DURATION()
{
return this._DURATION;
}
public void setPKG_DUARTION(int dur)
{
this._DURATION= dur;
}
public float getPKG_CHARGES()
{
return this._CHARGES;
}
public void setPKG_CHARGES(float charge)
{
this._CHARGES= charge;
}
}
activity_main.xml：
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<TextView android:layout_width="fill_parent"
android:layout_height="wrap_content" android:padding="10dp"
android:text="@string/some_text" android:textSize="20sp" />
<ListView
android:id="@+id/listView1"
android:layout_width="fill_parent"
android:layout_height="fill_parent" />
</RelativeLayout>
list_row.xml：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="@drawable/list_selector"
android:orientation="horizontal"
android:padding="5dip" >
<!-- ListRow Left sied Thumbnail image !-->
<LinearLayout android:id="@+id/thumbnail"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="3dip"
android:layout_alignParentLeft="true"
android:background="@drawable/image_bg"
android:layout_marginRight="5dip">
<ImageView
android:id="@+id/list_image"
android:layout_width="50dip"
android:layout_height="50dip"
android:src="@drawable/sms" android:contentDescription="@string/todo"/>
</LinearLayout>
<!-- Title Of Package-->
<TextView
android:id="@+id/name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignTop="@+id/thumbnail"
android:layout_toRightOf="@+id/thumbnail"
android:text="@string/pkg_title"
android:textColor="#040404"
android:typeface="sans"
android:textSize="15sp"
android:textStyle="bold"/>
<!--No of Free Items-->
<TextView
android:id="@+id/nsms"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_below="@id/name"
android:textColor="#343434"
android:textSize="12sp"
android:layout_marginTop="1dip"
android:layout_toRightOf="@+id/thumbnail"
android:text="@string/nitems" />
<!-- Duration -->
<TextView
android:id="@+id/duration"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignTop="@id/name"
android:gravity="right"
android:text="@string/dur"
android:layout_marginRight="5sp"
android:textSize="15sp"
android:textColor="#10bcc9"
android:textStyle="bold"/>
<!-- Charges -->
<TextView
android:id="@+id/spcharges"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/chargesofpkg"
android:gravity="right"
android:layout_alignParentRight="true"
android:layout_centerVertical="true"/>
</RelativeLayout>
任何幫助將高度讚賞。
您沒有粘貼MainActivity的代碼，其中拋出異常的類 –
是的，看起來您的問題似乎在MainActivity中的displayListView（）中，但我們看不到那是什麼問題。 – HalR