SQLite資料庫儲存

摘要： SQLite資料庫儲存 1.修改activity_main.xml: <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http:...

SQLite資料庫儲存

1.修改activity_main.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.sharepreferencetest.MainActivity">


<Button
android:id="@+id/button"

android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="儲存資料按鈕"
android:layout_weight="1"
/>


<Button
android:id="@+id/get_data"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="取出資料按鈕"
android:layout_weight="1"

/>

<Button
android:id="@+id/create_database"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="建立資料庫"
android:layout_weight="1"

/>


</LinearLayout>

2.建立MyDatavaseHelper:

package com.example.sharepreferencetest;


import android.content.Context;
import android.database.DatabaseErrorHandler;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.widget.Toast;

import java.security.interfaces.DSAKey;


public class MyDatavaseHelper extends SQLiteOpenHelper {

private static final String CREATE_BOOK = "create table Book(\n" +
"id integer primary key autoincrement,\n" +
"author text,\n" +
"price real,\n" +
"pages integer,\n" +
"name text\n" +
")";


private static final String CREATE_CATEGORY = "create table Category(\n" +
"id integer primary key autoincrement,\n" +
"category_name text,\n" +
"category_code integer\n" +
")\n";

private Context mContext;

public MyDatavaseHelper(Context context, String name,
SQLiteDatabase.CursorFactory factory, int version) {
super(context, name, factory, version);
mContext = context;
}

@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL(CREATE_BOOK);
db.execSQL(CREATE_CATEGORY);

System.out.println("建立了啊");
Toast.makeText(mContext, "建表成功!", Toast.LENGTH_LONG).show();

}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

db.execSQL("drop table if exists Book");
db.execSQL("drop table if exists Category");
onCreate(db);

}
}

3.MainActivity:

package com.example.sharepreferencetest;

import android.content.Context;
import android.content.SharedPreferences;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;

public class MainActivity extends AppCompatActivity {

private MyDatavaseHelper dbHelper;

private static final String TAG = "MainActivity";
Context context = getBaseContext();

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
dbHelper = new MyDatavaseHelper(this, "BookStore.db", null, 1);
Button createDatabase = (Button) findViewById(R.id.create_database);
createDatabase.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
dbHelper.getWritableDatabase();
}
});


Button button = (Button) findViewById(R.id.button);

button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {

SharedPreferences.Editor edit = getSharedPreferences(
"data", MODE_PRIVATE
).edit();

edit.putString("name", "張三");
edit.putInt("age", 15);
edit.putBoolean("old", false);
edit.apply();


}
});

Button getBut = (Button) findViewById(R.id.get_data);

getBut.setOnClickListener(

new View.OnClickListener() {
@Override
public void onClick(View v) {

SharedPreferences pref = getSharedPreferences("data", MODE_PRIVATE);
String name = pref.getString("name", null);
int age = pref.getInt("age", 0);
boolean old = pref.getBoolean("old", false);
Log.d(TAG, "onClick: " + name);
//Toast.makeText(context, name + " " + age + " " + old, Toast.LENGTH_LONG).show();
}

});

}
}