问题
Hi I am trying to insert data into database using EditText and Button I have created. I am stuck at Activity part of the code. I am unable to proceed how to write the Onclick action part for Button and EditText part Please help me. I am new to android
DBAdapter.java
package com.example.database1;
public class DBAdapter
{
public static final String KEY_ROWID = "_id";
public static final String KEY_ISBN = "isbn";
public static final String KEY_TITLE = "title";
public static final String KEY_PUBLISHER = "publisher";
private static final String TAG = "DBAdapter";
private static final String DATABASE_NAME = "books";
private static final String DATABASE_TABLE = "titles";
private static final int DATABASE_VERSION = 1;
private static final String DATABASE_CREATE =
"create table titles (_id integer primary key autoincrement, "
+ "isbn text not null, title text not null, "
+ "publisher text not null);";
private final Context context;
private DatabaseHelper DBHelper;
private SQLiteDatabase db;
public DBAdapter(Context ctx)
{
this.context = ctx;
DBHelper = new DatabaseHelper(context);
}
private static class DatabaseHelper extends SQLiteOpenHelper
{
DatabaseHelper(Context context)
{
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db)
{
db.execSQL(DATABASE_CREATE);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)
{
Log.w(TAG, "Upgrading database from version " + oldVersion
+ " to "
+ newVersion + ", which will destroy all old data");
db.execSQL("DROP TABLE IF EXISTS titles");
onCreate(db);
}
}
//---opens the database---
public DBAdapter open() throws SQLException
{
db = DBHelper.getWritableDatabase();
return this;
}
//---closes the database---
public void close()
{
DBHelper.close();
}
//---insert a title into the database---
public long insertTitle(String isbn, String title, String publisher)
{
ContentValues initialValues = new ContentValues();
initialValues.put(KEY_ISBN, isbn);
initialValues.put(KEY_TITLE, title);
initialValues.put(KEY_PUBLISHER, publisher);
return db.insert(DATABASE_TABLE, null, initialValues);
}
//---deletes a particular title---
public boolean deleteTitle(long rowId)
{
return db.delete(DATABASE_TABLE, KEY_ROWID +
"=" + rowId, null) > 0;
}
//---retrieves all the titles---
public Cursor getAllTitles()
{
return db.query(DATABASE_TABLE, new String[] {
KEY_ROWID,
KEY_ISBN,
KEY_TITLE,
KEY_PUBLISHER
},
null,
null,
null,
null,
null);
}
//---retrieves a particular title---
public Cursor getTitle(long rowId) throws SQLException
{
Cursor mCursor =
db.query(true, DATABASE_TABLE, new String[] {
KEY_ROWID,
KEY_ISBN,
KEY_TITLE,
KEY_PUBLISHER
},
KEY_ROWID + "=" + rowId,
null,
null,
null,
null,
null);
if (mCursor != null) {
mCursor.moveToFirst();
}
return mCursor;
}
//---updates a title---
public boolean updateTitle(long rowId, String isbn, String title, String publisher)
{
ContentValues args = new ContentValues();
args.put(KEY_ISBN, isbn);
args.put(KEY_TITLE, title);
args.put(KEY_PUBLISHER, publisher);
return db.update(DATABASE_TABLE, args,
KEY_ROWID + "=" + rowId, null) > 0;
}
}
DatabaseActivity.java
package com.example.database1;
public class DatabaseActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_database);
DBAdapter db = new DBAdapter(this);
db.open();
}
}
activity_database.xml:
<LinearLayout 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">
<EditText
android:id="@+id/edit1"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<EditText
android:id="@+id/edit2"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<EditText
android:id="@+id/edit3"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<Button
android:id="@+id/submit"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</LinearLayout>
回答1:
public class DatabaseActivity extends Activity {
EditText edit1,edit2,edit3;
Button submit;
@Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final DBAdapter db = new DBAdapter(this);
db.open();
edit1=(EditText)findViewById(R.id.edit1);
edit2=(EditText)findViewById(R.id.edit2);
edit3=(EditText)findViewById(R.id.edit3);
submit=(Button)findViewById(R.id.submit);
submit.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View v) {
String editText1=edit1.getText().toString();
String editText2=edit2.getText().toString();
String editText3=edit3.getText().toString();
long result=db.insertTitle(editText1, editText2, editText3);
Toast.makeText(MainActivity.this,"DataSaved",Toast.LENGTH_LONG).show();// TODO Auto-generated method stub
}
});
}
just paste it your database Activity and see the magic cheers..
回答2:
Change your code as to instert Edittext values in database on button click:
public class DatabaseActivity extends Activity {
DBAdapter db;
Button submitbtn;
EditText edit1,edit2,edit3;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_database);
db=new DBAdapter(this);
submitbtn = (Button) findViewById(R.id.submit);
edit1 = (EditText) findViewById(R.id.edit1);
edit2 = (EditText) findViewById(R.id.edit2);
edit3 = (EditText) findViewById(R.id.edit3);
db.open();
submitbtn.setOnClickListener(new OnClickListener()
{
public void onClick(View v)
{
String steedtone=edit1.getText().toString();
String steedttwo=edit2.getText().toString();
String steedtthree=edit3.getText().toString();
long result=db.insertTitle(steedtone,steedttwo,steedtthree);
}
});
}
}
回答3:
This will come inside your onCreate() after setContentView() is called.
Button btn = (Button) findViewById(R.id.btnId);
EditText edtTxt = (EditText) findViewById(R.id.edtId);
btn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
insertDataInDb();
}
});
public void insertDataInDb() {
// TODO Auto-generated method stub
String str = edtTxt.getText().toString();
//Code for insertion
}
回答4:
check below code.
package com.example.database1;
import android.os.Bundle;
import android.app.Activity;
import android.database.Cursor;
import android.view.Menu;
import android.widget.Toast;
public class DatabaseActivity extends Activity {
DBAdapter db;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_database);
db = new DBAdapter(this);
db.open();
Button btn = (Button) findViewById(R.id.btnId);
EditText edtTxt = (EditText) findViewById(R.id.edtId);
btn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
String name = edtTxt.getText().toString();
try{
insertTitle("ISBN",""+name,"publisar");
}catch(Exception e){
Log.d("error-->","insert data-->"+e.getMassage().toString());
}
}
});
}
}
来源：https://stackoverflow.com/questions/13853279/storing-data-in-a-database-using-edit-text-and-button