嗨，我是新手Android和java.I有关于我的代码的问题。我想在数据库中插入数据后显示吐司，我想在插入和显示toast messega（错误的值）之前从数据库检查值edittext。任何人都可以告诉我该怎么办？
这是我的插页码。
package com.androidmeret.aractakip;
import android.app.Activity;
import android.app.DatePickerDialog;
import android.content.Intent;
import android.database.sqlite.SQLiteDatabase;
import android.support.v4.app.Fragment;
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.os.Build;
import android.widget.Button;
import android.widget.DatePicker;
import android.widget.EditText;
import android.widget.Toast;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
public class YakitEkleActivity extends Activity {
Button yeniYakitEkle;
Button yeniYakitIptal;
EditText alinanYakitdeger;
EditText alinanLt;
EditText aracKm;
String selectedCarName;
String fdate;
DBController dbyakit = new DBController(this);
Calendar date = Calendar.getInstance();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_yakit_ekle);
yeniYakitEkle =(Button) findViewById(R.id.yakitekle_ekle);
yeniYakitIptal =(Button)findViewById(R.id.yakitekle_iptal);
alinanLt = (EditText) findViewById(R.id.yakitekle_alinanyakit);
alinanYakitdeger =(EditText) findViewById(R.id.yakitekle_ltfiyat);
aracKm =(EditText) findViewById(R.id.yakitekle_arackm);
selectedCarName = getIntent().getStringExtra("selected_car_name");
fdate = java.text.DateFormat.getDateTimeInstance().format(Calendar.getInstance().getTime());
final DatePickerDialog.OnDateSetListener d=new DatePickerDialog.OnDateSetListener() {
public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth) {
date.set(Calendar.YEAR, year);
date.set(Calendar.MONTH, monthOfYear);
date.set(Calendar.DAY_OF_MONTH, dayOfMonth);
dbyakit.insertYakit(selectedCarName, alinanLt.getText().toString(), alinanYakitdeger.getText().toString(), aracKm.getText().toString(), dayOfMonth, monthOfYear, year);
Intent yakitMain = new Intent (getApplicationContext(),YakitActivity.class);
yakitMain.putExtra("selected_car_name", selectedCarName);
startActivity(yakitMain);
}
};
yeniYakitEkle.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
//if(checkKm()=true){
new DatePickerDialog(YakitEkleActivity.this, d, date.get(Calendar.YEAR), date.get(Calendar.MONTH), date.get(Calendar.DAY_OF_MONTH)).show();
//}else{
// Toast.makeText(getApplicationContext(),"Girilen KM hatalı",Toast.LENGTH_LONG).show();
//}
}
});
yeniYakitIptal.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent backYakit = new Intent(getApplicationContext(), YakitActivity.class);
backYakit.putExtra("selected_car_name", selectedCarName);
startActivity(backYakit);
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.yakit_ekle, 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();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_yakit_ekle, container, false);
return rootView;
}
}
}
这是我的dbhelper ......
package com.androidmeret.aractakip;
import java.util.ArrayList;
import java.util.List;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
import android.widget.Toast;
public class DBController extends SQLiteOpenHelper {
private static final String DATABASE_NAME="aractakip.db";
private static String LOGCAT = null;
private static final int SURUM = 1;
//CARS tablosu...
private static final String TABLO_ADI = "CARS";
private static final String SATIR_ID = "cid";
private static final String SATIR_ADI = "cname";
private static final String SATIR_MODEL ="cmodel";
private static final String SATIR_MARKA ="cbrand";
private static final String SATIR_YIL ="cyear";
private static final String SATIR_KM ="ckm";
//FUEL tablosu...
private static final String FUEL_TABLO_ADI = "FUEL";
private static final String FUEL_ID = "fid";
private static final String FUEL_SATIR_ADI = "fcarid";
private static final String FUEL_LT = "flitre";
private static final String FUEL_FIYAT ="ffiyat";
private static final String FUEL_KM ="fkm";
private static final String FUEL_DATE_D = "fdated";
private static final String FUEL_DATE_M = "fdatem";
private static final String FUEL_DATE_Y = "fdatey";
Integer aracLastKm;
Integer girilenKm;
int lastKm;
public DBController(Context dbcontext){
super(dbcontext,DATABASE_NAME,null,SURUM);
Log.d(LOGCAT, "Database yaratıldı.");
}
@Override
public void onCreate(SQLiteDatabase db) {
String queryTable = "CREATE TABLE " + TABLO_ADI + "(" + SATIR_ID + " INTEGER PRIMARY KEY," + SATIR_ADI +" TEXT,"+ SATIR_MODEL + " TEXT,"+ SATIR_MARKA + " TEXT,"+ SATIR_YIL + " TEXT,"+ SATIR_KM + " TEXT)";
String queryFuel = "CREATE TABLE " + FUEL_TABLO_ADI + "("+ FUEL_ID + " INTEGER PRIMARY KEY," + FUEL_SATIR_ADI + " TEXT," + FUEL_LT + " TEXT,"+ FUEL_FIYAT + " TEXT," + FUEL_KM + " TEXT," + FUEL_DATE_D + " INTEGER, "+ FUEL_DATE_M + " INTEGER, " + FUEL_DATE_Y + " INTEGER)";
db.execSQL(queryTable);
db.execSQL(queryFuel);
Log.d(LOGCAT, "Fuel Tablo yaratldı.");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
String queryUpdatedb = "DROP TABLE IF EXISTS " + TABLO_ADI;
db.execSQL(queryUpdatedb);
}
/* public boolean checkKm(String fcarid, String userKm){
SQLiteDatabase cardatabase = getReadableDatabase();
String query1 = "SELECT " + FUEL_KM + " FROM "+ FUEL_TABLO_ADI + " WHERE " + FUEL_SATIR_ADI + " = '"+ fcarid + "'"+ " ORDER BY " + FUEL_ID +" DESC LIMIT 1";
Cursor check = cardatabase.rawQuery(query1,null);
lastKm = Integer.parseInt(userKm);
if (check.getCount()==0){
aracLastKm = 0;
}else {
check.moveToFirst();
aracLastKm = check.getInt(0);
}
if (aracLastKm == 0 || lastKm > aracLastKm){
return true;
}
return false;
}
*/
public void insertYakit(String fcarid, String flitre,String ffiyat, String fkm, int fdated,int fdatem, int fdatey ){
SQLiteDatabase cardatabase = this.getWritableDatabase();
String query1 = "SELECT " + FUEL_KM + " FROM "+ FUEL_TABLO_ADI + " WHERE " + FUEL_SATIR_ADI + " = '"+ fcarid + "'"+ " ORDER BY " + FUEL_ID +" DESC LIMIT 1";
Cursor check = cardatabase.rawQuery(query1,null);
girilenKm = Integer.parseInt(fkm);
if (check.getCount()==0){
aracLastKm = 0;
}else {
check.moveToFirst();
aracLastKm = check.getInt(0);
}
if( check.getCount() == 0 || girilenKm > aracLastKm ){
ContentValues values = new ContentValues();
values.put(FUEL_SATIR_ADI,fcarid);
values.put(FUEL_LT,flitre);
values.put(FUEL_FIYAT,ffiyat);
values.put(FUEL_KM,fkm);
values.put(FUEL_DATE_D,fdated);
values.put(FUEL_DATE_M,fdatem);
values.put(FUEL_DATE_Y, fdatey);
cardatabase.insert(FUEL_TABLO_ADI, null, values);
cardatabase.close();
Log.d(LOGCAT, "Veri kaydedildi.");
}else {
Log.d(LOGCAT, "Girilen KM hatalı.");
}
cardatabase.close();
check.close();
}
//Database araç kayıt...
public void insertCar(String name,String model,String brand,String year,String km){
SQLiteDatabase cardatabase = this.getWritableDatabase();
String searchQuery = "SELECT " + SATIR_ID +","+ SATIR_ADI + " FROM " + TABLO_ADI + " WHERE " + SATIR_ADI +" = '" + name.toString()+"'" ;
Cursor cursor = cardatabase.rawQuery(searchQuery, null);
if (cursor.getCount() == 0){
ContentValues values = new ContentValues();
values.put(SATIR_ADI,name);
values.put(SATIR_MODEL,model);
values.put(SATIR_MARKA,brand);
values.put(SATIR_YIL,year);
values.put(SATIR_KM,km);
cardatabase.insert(TABLO_ADI, null, values);
cardatabase.close();
Log.d(LOGCAT, "Veri kaydedildi.");
}
else{
Log.d(LOGCAT, "Aynı isim var");
}
cursor.close();
cardatabase.close();
}
//Araçları spinner doldurur...
public List<String> getAllLabels(){
SQLiteDatabase cardatabase =this.getWritableDatabase();
List<String> labels = new ArrayList<String>();
String selectQuery = "SELECT "+ SATIR_ADI + " FROM " + TABLO_ADI;
Cursor cursor = cardatabase.rawQuery(selectQuery, null);
if (cursor.moveToFirst()) {
do {
labels.add(cursor.getString(0));
} while (cursor.moveToNext());
}
cursor.close();
cardatabase.close();
return labels;
}
//Spinner'da seçilen aracı siler.
public void deleteCar(String cname){
SQLiteDatabase cardatabase = this.getWritableDatabase();
String deleteQuery = "DELETE FROM " + TABLO_ADI +" WHERE " + SATIR_ADI + " = '"+ cname +"'";
cardatabase.execSQL(deleteQuery);
Log.d(LOGCAT, "Araç silindi");
cardatabase.close();
}
}
答案 0 :(得分：1)
更改insertCar方法以返回布尔结果。像那样：
public boolean insertCar(String name,String model,String brand,String year,String km){
SQLiteDatabase cardatabase = this.getWritableDatabase();
String searchQuery = "SELECT " + SATIR_ID +","+ SATIR_ADI + " FROM " + TABLO_ADI + " WHERE " + SATIR_ADI +" = '" + name.toString()+"'" ;
Cursor cursor = cardatabase.rawQuery(searchQuery, null);
boolean c;
if (cursor.getCount() == 0){
ContentValues values = new ContentValues();
values.put(SATIR_ADI,name);
values.put(SATIR_MODEL,model);
values.put(SATIR_MARKA,brand);
values.put(SATIR_YIL,year);
values.put(SATIR_KM,km);
cardatabase.insert(TABLO_ADI, null, values);
cardatabase.close();
Log.d(LOGCAT, "Veri kaydedildi.");
c=true;
}
else{
Log.d(LOGCAT, "Aynı isim var");
c=false;
}
cursor.close();
cardatabase.close();
return c;
}`
和你的
dbyakit.insertYakit
要insertCar，请尝试：
if (dbyakit.insertYakit(selectedCarName, alinanLt.getText().toString(), alinanYakitdeger.getText().toString(), aracKm.getText().toString(), dayOfMonth, monthOfYear, year))
// Case return true
Toast.makeText(rootView.getContext(), "Yout text here", Toast.LENGTH_LONG).show();
else
// Case return false
Toast.makeText(rootView.getContext(), "Yout text here", Toast.LENGTH_LONG).show();
干杯！