**
我想在SQLite数据库列表视图中删除并更新一行
使用Alert对话框在任何项目上计时。
操作不正常，这是什么错误？
08-25 09：40：14.429 8664-8664 / com.example.user.dbprojectsqlite E / SpannableStringBuilder：SPAN_EXCLUSIVE_EXCLUSIVE范围不能包含
零长度
SPAN_EXCLUSIVE_EXCLUSIVE跨度不能为零长度
08-25 09：40：53.180 8664-8664 / com.example.user.dbprojectsqlite E / SpannableStringBuilder：SPAN_EXCLUSIVE_EXCLUSIVE范围不能包含
零长度
SPAN_EXCLUSIVE_EXCLUSIVE跨度不能为零长度
**
MyDatabaseHelper.java
package com.example.user.dbprojectsqlite;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.support.v4.app.ActivityCompat;
import android.widget.Toast;
public class MyDatabaseHelper extends SQLiteOpenHelper {
private static final String DATABASE_NAME="Gymnesium";
private static final String TRAINEE_TABLE_NAME="Trainee";
private static final int VERSION_NUMBER=5;
static final String TRAINEE_ID="traineeId";
static final String TRAINEE_NAME="traineeName";
static final String TRAINEE_AGE="traineeAge";
static final String TRAINEE_GENDER="traineeGender";
static final String TRAINEE_IMAGE="traineeImage";
private static final String CREAE_TABLE_TRAINEE="CREATE TABLE "
+TRAINEE_TABLE_NAME+"("+TRAINEE_ID+" INTEGER PRIMARY KEY AUTOINCREMENT," +
""+TRAINEE_NAME+" VARCHAR(255),"+TRAINEE_AGE+" INTEGER,"+TRAINEE_GENDER+" VARCHAR(255))";
private static final String DROP_TABLE_TRAINEE="DROP TABLE IF EXISTS "+TRAINEE_TABLE_NAME;
private Context context;
public MyDatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, VERSION_NUMBER);
this.context=context;
}
@Override
public void onCreate(SQLiteDatabase sqLiteDatabase) {
try{
Toast.makeText(context,"onCreate is called",Toast.LENGTH_SHORT).show();
sqLiteDatabase.execSQL(CREAE_TABLE_TRAINEE);
}catch (Exception e){
Toast.makeText(context,"Exception :"+e,Toast.LENGTH_SHORT).show();
}
}
@Override
public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {
try {
Toast.makeText(context,"onCreate is called",Toast.LENGTH_SHORT).show();
sqLiteDatabase.execSQL(DROP_TABLE_TRAINEE);
onCreate(sqLiteDatabase);
}catch (Exception e){
Toast.makeText(context,"Exception :"+e,Toast.LENGTH_SHORT).show();
}
}
public long insertData(String name,String age,String gender){
SQLiteDatabase sqLiteDatabase=this.getWritableDatabase();
ContentValues contentValues=new ContentValues();
//contentValues.put(TRAINEE_IMAGE,traineeImg);
contentValues.put(TRAINEE_NAME,name);
contentValues.put(TRAINEE_AGE,age);
contentValues.put(TRAINEE_GENDER,gender);
long rowId=sqLiteDatabase.insert(TRAINEE_TABLE_NAME,null,contentValues);
return rowId;
}
public Cursor displayAllData(){
SQLiteDatabase sqLiteDatabase=this.getWritableDatabase();
Cursor cursor=sqLiteDatabase.rawQuery("SELECT * FROM "+TRAINEE_TABLE_NAME,null);
return cursor;
}
public Boolean updateData(String id,String name,String age,String gender){
SQLiteDatabase sqLiteDatabase=this.getWritableDatabase();
ContentValues contentValues=new ContentValues();
contentValues.put(TRAINEE_ID,id);
contentValues.put(TRAINEE_NAME,name);
contentValues.put(TRAINEE_AGE,age);
contentValues.put(TRAINEE_GENDER,gender);
sqLiteDatabase.update(TRAINEE_TABLE_NAME,contentValues,TRAINEE_ID+" = ?",new String[]{id});
return true;
}
public int deleteData(String id){
SQLiteDatabase sqLiteDatabase=this.getWritableDatabase();
return sqLiteDatabase.delete(TRAINEE_TABLE_NAME,TRAINEE_ID+" = ?",new String[]{id});
}
}
TraineeListActivity.java
package com.example.user.dbprojectsqlite;
import android.app.Activity;
import android.app.Dialog;
import android.content.DialogInterface;
import android.database.Cursor;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.Toast;
import java.util.ArrayList;
public class TraineeListActivity extends AppCompatActivity {
private ListView TraineeListView;
private MyDatabaseHelper myDatabaseHelper;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_trainee_list);
TraineeListView=findViewById(R.id.traineeList);
myDatabaseHelper=new MyDatabaseHelper(this);
loadData();
}
public void loadData(){
ArrayList<String>traineeListData=new ArrayList<>();
Cursor cursor=myDatabaseHelper.displayAllData();
if(cursor.getCount()==0){
Toast.makeText(getApplicationContext(),"No data is available",Toast.LENGTH_SHORT).show();
}else {
while (cursor.moveToNext()){
traineeListData.add("ID :"+cursor.getString(0)+" \n "+"Name :"+cursor.getString(1)+" \n "+"Age :"+cursor.getString(2)+" \n "+"Gender :"+cursor.getString(3));
}
}
ArrayAdapter<String>adapter=new ArrayAdapter<String>(this,R.layout.trainee_item,R.id.traineeTextView,traineeListData);
TraineeListView.setAdapter(adapter);
TraineeListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, final int position, long l) {
//String SelectedItem=adapterView.getItemAtPosition(i).toString();
//Toast.makeText(TraineeListActivity.this,"Selected item: "+SelectedItem,Toast.LENGTH_SHORT).show();
CharSequence[] items={"update","delete"};
AlertDialog.Builder dialog=new AlertDialog.Builder(TraineeListActivity.this);
dialog.setTitle("Choose an action");
dialog.setItems(items, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
if(i==0){
Cursor c=myDatabaseHelper.displayAllData();
ArrayList<Integer>arrId=new ArrayList<>();
while ((c.moveToNext())){
arrId.add(c.getInt(0));
}
showDialogUpdate(TraineeListActivity.this,arrId.get(position));
}
if(i==1){
Cursor c=myDatabaseHelper.displayAllData();
ArrayList<Integer>arrId=new ArrayList<Integer>();
while ((c.moveToNext())){
arrId.add(c.getInt(0));
}
showDialogDelete(arrId.get(position));
}
}
});
dialog.show();
}
});
}
private void showDialogDelete(final int idRecord) {
final AlertDialog.Builder dialogDelete=new AlertDialog.Builder(TraineeListActivity.this);
dialogDelete.setTitle("Warning!!");
dialogDelete.setMessage("Are you sure to delete?");
// final EditText idText=findViewById(R.id.idET);
dialogDelete.setPositiveButton("OK", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
try {
myDatabaseHelper.deleteData(MyDatabaseHelper.TRAINEE_ID);
Toast.makeText(TraineeListActivity.this,"Deleted data",Toast.LENGTH_SHORT).show();
}catch (Exception e){
Log.e("error",e.getMessage());
}
}
});
dialogDelete.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
dialogInterface.dismiss();
}
});
dialogDelete.show();
}
private void showDialogUpdate(Activity activity, final int position){
final Dialog dialog=new Dialog(activity);
dialog.setContentView(R.layout.trainee_update);
dialog.setTitle("Update");
final EditText idText=dialog.findViewById(R.id.idET);
final EditText nameText=dialog.findViewById(R.id.nameET);
final EditText ageText=dialog.findViewById(R.id.ageET);
final EditText genText=dialog.findViewById(R.id.genderET);
Button updateBT=dialog.findViewById(R.id.updateBtn);
int width=(int)(activity.getResources().getDisplayMetrics().widthPixels*0.95);
int height=(int)(activity.getResources().getDisplayMetrics().heightPixels*0.7);
dialog.getWindow().setLayout(width,height);
dialog.show();
updateBT.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
try {
myDatabaseHelper.updateData(
idText.getText().toString().trim(),
nameText.getText().toString().trim(),
ageText.getText().toString().trim(),
genText.getText().toString().trim()
);
dialog.dismiss();
Toast.makeText(getApplicationContext(),"Update Successfully",Toast.LENGTH_SHORT).show();
}catch (Exception e){
Log.e("Update error",e.getMessage());
}
myDatabaseHelper.updateData(MyDatabaseHelper.TRAINEE_ID,MyDatabaseHelper.TRAINEE_NAME,MyDatabaseHelper.TRAINEE_AGE,MyDatabaseHelper.TRAINEE_GENDER);
}
});
}
/* private void updateTraineeList() {
Cursor cursor=myDatabaseHelper.displayAllData();
TraineeListView.clear();
while (cursor.moveToNext()){
int id=cursor.getInt(0);
String name=cursor.getString(1);
String age=cursor.getString(2);
String phone=cursor.getString(3);
}
}*/
}
最佳答案
尝试此操作，您传递idRecord从表而不是My DatabaseHelper.TRAINEE ID删除数据
private void showDialogDelete(final int idRecord) {
final AlertDialog.Builder dialogDelete=new AlertDialog.Builder(TraineeListActivity.this);
dialogDelete.setTitle("Warning!!");
dialogDelete.setMessage("Are you sure to delete?");
// final EditText idText=findViewById(R.id.idET);
dialogDelete.setPositiveButton("OK", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
try {
myDatabaseHelper.deleteData(idRecord);
Toast.makeText(TraineeListActivity.this,"Deleted data",Toast.LENGTH_SHORT).show();
}catch (Exception e){
Log.e("error",e.getMessage());
}
}
});
dialogDelete.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
dialogInterface.dismiss();
}
});
dialogDelete.show();
}