Java Android Studio从Reyclerview和Sqlitedb中删除所有行
在MarkerDisplayActivity中,我试图确认用户是否需要 要从行和数据库中删除所有列出的项,请执行以下操作:?我 尝试了clear()和其他类型,行将被删除,但如果我返回 然后再次转到RV删除的行将返回,因为它们仍然保存 在数据库中 这是我的密码:Java Android Studio从Reyclerview和Sqlitedb中删除所有行,java,android,android-studio,android-recyclerview,Java,Android,Android Studio,Android Recyclerview,在MarkerDisplayActivity中,我试图确认用户是否需要 要从行和数据库中删除所有列出的项,请执行以下操作:?我 尝试了clear()和其他类型,行将被删除,但如果我返回 然后再次转到RV删除的行将返回,因为它们仍然保存 在数据库中 这是我的密码: package elevatesecurity.myapplication; import android.app.Dialog; import android.content.DialogInterface; import andr
package elevatesecurity.myapplication;
import android.app.Dialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.Toolbar;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GoogleApiAvailability;
import java.util.ArrayList;
import java.util.List;
import elevatesecurity.myapplication.Adapters.MarkerAdapter;
import elevatesecurity.myapplication.Model.MarkerModel;
import elevatesecurity.myapplication.Utilities.MarkerDatabaseHelper;
public class MarkerDisplayActivity extends AppCompatActivity {
RecyclerView recyclerView;
MarkerAdapter markerAdapter;
ArrayList<MarkerModel> modelArrayList;
// private ArrayList<MarkerModel> marker_list = new ArrayList<>();
MarkerDatabaseHelper markerDatabaseHelper;
TextView textView;
Toolbar toolBar;
List<MarkerModel> markerList;
private static final int ERROR_DIALOG_REQUEST = 9001;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_marker_display);
textView = (TextView)findViewById(R.id.markerInfotxt);
markerDatabaseHelper = new MarkerDatabaseHelper(this);
recyclerView = (RecyclerView)findViewById(R.id.recyclerview);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
modelArrayList = markerDatabaseHelper.getAllMarkers();
android.support.v7.widget.Toolbar toolBar = (android.support.v7.widget.Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolBar);
if (isServicesOk()) {
}
if(modelArrayList.size()>0)
{
textView.setVisibility(View.GONE);
markerAdapter = new MarkerAdapter(this,modelArrayList);
recyclerView.setAdapter(markerAdapter);
markerAdapter.notifyDataSetChanged();
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu)
{
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.menu_marker, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item)
{
switch (item.getItemId())
{
case R.id.action_removeAll:
android.support.v7.app.AlertDialog.Builder builder;
builder = new android.support.v7.app.AlertDialog.Builder(MarkerDisplayActivity.this);
builder.setTitle("Confirm!")
.setMessage("Are You Sure You Want To Remove All Saved Locations?")
.setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener()
{
public void onClick(DialogInterface dialog, int which)
{
modelArrayList.clear();
markerAdapter.notifyDataSetChanged();
}
})
.setNegativeButton(android.R.string.no, new DialogInterface.OnClickListener()
{
public void onClick(DialogInterface dialog, int which)
{
return;
}
})
.setIcon(android.R.drawable.ic_dialog_alert)
.show();
break;
}
return super.onOptionsItemSelected(item);
}
public boolean isServicesOk()
{
Log.d("", "ifServicesOk: checking google services version");
int available = GoogleApiAvailability.getInstance()
.isGooglePlayServicesAvailable(MarkerDisplayActivity.this);
if (available == ConnectionResult.SUCCESS) {
// Everything is fine and the user can make a map request
Log.d("", "ifServicesOk: Google play services is working");
return true;
} else if (GoogleApiAvailability.getInstance().isUserResolvableError(available)) {
// An error occurred but we can resolve it
Log.d("", "ifServicesOk: An error occurred but we can fix it");
Dialog dialog = GoogleApiAvailability.getInstance().getErrorDialog
(MarkerDisplayActivity.this, available, ERROR_DIALOG_REQUEST);
dialog.show();
} else {
Toast.makeText(this, "You can't make a map request"
, Toast.LENGTH_SHORT).show();
}
return false;
}
}
public class MarkerDatabaseHelper extends SQLiteOpenHelper
{
public static final String DB_NAME = "markers.db";
public static final int DB_VERSION = 1;
public static final String TABLE_NAME = "markertable";
public static final String COLUMN_ID = "id";
public static final String COLUMN_LAT = "lat";
public static final String COLUMN_LNG = "lng";
public static final String COLUMN_TITLE = "title";
public MarkerDatabaseHelper(Context context) {
super(context, TABLE_NAME, null, DB_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("create table " + TABLE_NAME + "(id INTEGER PRIMARY KEY AUTOINCREMENT," +
"lat TEXT, "+
"lng TEXT, title TEXT)");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
onCreate(db);
}
public boolean insertMarker(String lat,String lng,String title)
{
SQLiteDatabase db = this.getWritableDatabase();
ContentValues contentValues = new ContentValues();
contentValues.put(COLUMN_LAT, lat);
contentValues.put(COLUMN_LNG, lng);
contentValues.put(COLUMN_TITLE, title);
// Insert the row into your table
long ins = db.insert(TABLE_NAME, null, contentValues);
if (ins == -1) return false;
else return true;
}
public ArrayList<MarkerModel> getAllMarkers()
{
ArrayList<MarkerModel> arrayListMarkers = new ArrayList<>();
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery("Select * from "+TABLE_NAME,null);
while(cursor.moveToNext())
{
int id = cursor.getInt(0);
String lat = cursor.getString(1);
String lng = cursor.getString(2);
String title = cursor.getString(3);
MarkerModel markerModel = new MarkerModel(id,lat,lng,title);
arrayListMarkers.add(markerModel);
}
cursor.close();
return arrayListMarkers;
}
public void deleteRow(int value)
{
SQLiteDatabase db = this.getWritableDatabase();
db.execSQL("DELETE FROM " + TABLE_NAME+ " WHERE "+COLUMN_ID+"='"+value+"'");
}
public void deleteRows(int value)
{
SQLiteDatabase db = this.getWritableDatabase();
db.execSQL("DELETE * FROM " + TABLE_NAME + " WHERE " + COLUMN_ID + " =' " + value + " ' ");
}
}
package elevatesecurity.myapplication.Adapters;
public class MarkerAdapter extends RecyclerView.Adapter<MarkerAdapter.MarkerViewHolder> {
// The MarkerModel is the name of the existed activity called MarkerModel
List<MarkerModel> markerList;
Context mCtx;
public MarkerAdapter(Context mCtx, List<MarkerModel> markerList)
{
this.mCtx = mCtx;
this.markerList = markerList;
}
@Override
public MarkerViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view= LayoutInflater.from(mCtx).inflate(R.layout.item_marker,parent,false);
return new MarkerViewHolder(view);
}
@Override
public void onBindViewHolder(MarkerViewHolder holder, int position) {
holder.titleTxt.setText(markerList.get(position).getTitle());
}
@Override
public int getItemCount() {
return markerList.size();
}
public class MarkerViewHolder extends RecyclerView.ViewHolder
{
TextView titleTxt;
Button buttonOptions;
public MarkerViewHolder(final View itemView)
{
super(itemView);
titleTxt = (TextView)itemView.findViewById(R.id.titleTxt);
buttonOptions = (Button)itemView.findViewById(R.id.buttonOptions);
itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
MarkerModel markerModel = markerList.get(getAdapterPosition());
Intent i = new Intent(mCtx, DisplayMapActivity.class);
i.putExtra("lat",markerModel.getLat());
i.putExtra("lng",markerModel.getLng());
i.putExtra("title",markerModel.getTitle());
mCtx.startActivity(i);
}
});
buttonOptions.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
try {
PopupMenu popupMenu = new PopupMenu(mCtx, buttonOptions);
popupMenu.getMenuInflater().inflate(R.menu.menu_contextual, popupMenu.getMenu());
popupMenu.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
@Override
public boolean onMenuItemClick(MenuItem item) {
MarkerDatabaseHelper db = new MarkerDatabaseHelper(mCtx);
db.deleteRow(markerList.get(getAdapterPosition()).getId());
markerList.remove(getAdapterPosition());
// Recent_Adapter.this.notify();
notifyDataSetChanged();
notifyItemRemoved(getAdapterPosition());
return true;
}
});
popupMenu.show();
}catch(Exception e)
{
e.printStackTrace();
}
}
});
}
}
}
包提升安全性.myapplication;
导入android.app.Dialog;
导入android.content.DialogInterface;
导入android.content.Intent;
导入android.support.v7.app.AppActivity;
导入android.os.Bundle;
导入android.support.v7.widget.LinearLayoutManager;
导入android.support.v7.widget.RecyclerView;
导入android.util.Log;
导入android.view.Menu;
导入android.view.MenuInflater;
导入android.view.MenuItem;
导入android.view.view;
导入android.widget.TextView;
导入android.widget.Toast;
导入android.widget.Toolbar;
导入com.google.android.gms.common.ConnectionResult;
导入com.google.android.gms.common.GoogleAppAvailability;
导入java.util.ArrayList;
导入java.util.List;
导入elevatesecurity.myapplication.Adapters.MarkeraAdapter;
导入elevatesecurity.myapplication.Model.MarkerModel;
导入elevatesecurity.myapplication.Utilities.MarkerDatabaseHelper;
公共类MarkerDisplayActivity扩展了AppCompatActivity{
回收视图回收视图;
标记适配器标记适配器;
ArrayList模型ArrayList;
//private ArrayList marker_list=new ArrayList();
MarkerDatabaseHelper MarkerDatabaseHelper;
文本视图文本视图;
工具栏;
列表标记列表;
私有静态最终整数错误对话框请求=9001;
@凌驾
创建时受保护的void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity\u marker\u display);
textView=(textView)findViewById(R.id.markerInfotxt);
markerDatabaseHelper=新的markerDatabaseHelper(此);
recyclerView=(recyclerView)findViewById(R.id.recyclerView);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(新的LinearLayoutManager(本));
modelArrayList=markerDatabaseHelper.getAllMarkers();
android.support.v7.widget.Toolbar=(android.support.v7.widget.Toolbar)findviewbyd(R.id.Toolbar);
设置支持操作栏(工具栏);
if(isServicesOk()){
}
如果(modelArrayList.size()>0)
{
textView.setVisibility(View.GONE);
MarkeraAdapter=新的MarkeraAdapter(此为modelArrayList);
recyclerView.setAdapter(MarkeraAdapter);
markerAdapter.notifyDataSetChanged();
}
}
@凌驾
公共布尔onCreateOptions菜单(菜单)
{
MenuInflater充气机=getMenuInflater();
充气机。充气(右菜单。菜单标记,菜单);
返回true;
}
@凌驾
公共布尔值onOptionsItemSelected(菜单项项)
{
开关(item.getItemId())
{
案例R.id.action\u removeAll:
android.support.v7.app.AlertDialog.Builder;
builder=newandroid.support.v7.app.AlertDialog.builder(MarkerDisplayActivity.this);
builder.setTitle(“确认!”)
.setMessage(“确实要删除所有保存的位置吗?”)
.setPositiveButton(android.R.string.yes,新的DialogInterface.OnClickListener()
{
public void onClick(DialogInterface dialog,int which)
{
modelArrayList.clear();
markerAdapter.notifyDataSetChanged();
}
})
.setNegativeButton(android.R.string.no,新的DialogInterface.OnClickListener()
{
public void onClick(DialogInterface dialog,int which)
{
回来
}
})
.setIcon(android.R.drawable.ic_对话框_警报)
.show();
打破
}
返回super.onOptionsItemSelected(项目);
}
公共布尔值isServicesOk()
{
Log.d(“,“ifServicesOk:检查谷歌服务版本”);
int available=GoogleApiAvailability.getInstance()
.isGooglePlayServicesAvailable(MarkerDisplayActivity.this);
如果(可用==ConnectionResult.SUCCESS){
//一切正常,用户可以发出地图请求
Log.d(“,”ifServicesOk:googleplayservices正在工作“);
返回true;
}else if(GoogleAppAvailability.getInstance().isUserResolvableError(可用)){
//发生错误,但我们可以解决它
Log.d(“,”ifServicesOk:发生错误,但我们可以修复它”);
Dialog Dialog=GoogleAppAvailability.getInstance().getErrorDialog
(MarkerDisplayActivity.this,可用,错误对话框请求);
dialog.show();
}否则{
Toast.makeText(这是“您不能进行映射请求”
,Toast.LENGTH_SHORT)show();
}
返回false;
}
}
公共类MarkerDatabaseHelper扩展了SQLiteOpenHelper
{
公共静态最终字符串DB_NAME=“markers.DB”;
公共静态最终int DB_版本=1;
公共静态最终字符串表\u NAME=“markertable”;
公共静态最终字符串列\u ID=“ID”;
公共静态最终字符串列_LAT=“LAT”;
公共静态最终管柱\u LNG=“LNG”;
公共静态最终字符串列\u TITLE=“TITLE”;
公共MarkerDatabaseHelper(上下文){
super(上下文、表名称、null、DB\u版本);
}
@凌驾
public void onCreate(SQLiteDatabase db){
db.execSQL(“创建表”+表名称+”(id整数主键自动递增
public void deleteAllRows() {
SQLiteDatabase db = this.getWritableDatabase();
db.execSQL("DELETE FROM " + TABLE_NAME);
}
db.deleteAllRows();
modelArrayList.clear();
markerAdapter.notifyDataSetChanged();
int counter = db.delete(TABLE_NAME, null, null);