極客學院案例-記事本程式碼
阿新 • • 發佈：2019-01-26
*資料庫檔案NotesDB
package com.jikexueyuan.hellonotes;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;
public class NotesDB extends SQLiteOpenHelper {
public MainActivity頁面
package com.jikexueyuan.hellonotes;
import android.app.Activity;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.Button;
import android.widget.ListView;
public class MainActivity extends Activity implements OnClickListener {
private NotesDB notesDB;
private SQLiteDatabase dbReader;
private Button textbtn, imgbtn, videobtn;
private ListView lv;
private Intent i;
private MyAdapter adapter;
private Cursor cursor;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initView();
}
public void initView() {
lv = (ListView) findViewById(R.id.list);
textbtn = (Button) findViewById(R.id.text);
imgbtn = (Button) findViewById(R.id.img);
videobtn = (Button) findViewById(R.id.video);
textbtn.setOnClickListener(this);
imgbtn.setOnClickListener(this);
videobtn.setOnClickListener(this);
notesDB = new NotesDB(this);//初始化資料庫檔案，獲取資料庫例項
dbReader = notesDB.getReadableDatabase();//獲取讀取許可權
/**
* 實現listview每個子項的單機事件
*/
lv.setOnItemClickListener(new OnItemClickListener(){
@Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
Log.d("TAG", position+"");
Log.d("TAG", id+"");
cursor.moveToPosition(position);//指標指向當前使用者點選的位置position,利用指標取出這個位置在資料庫的其他列資料
Intent intent = new Intent(MainActivity.this,SelectAtc.class);
intent.putExtra(NotesDB.ID, cursor.getInt(cursor.getColumnIndex(NotesDB.ID)));
intent.putExtra(NotesDB.CONTENT, cursor.getString(cursor.getColumnIndex(NotesDB.CONTENT)));
intent.putExtra(NotesDB.TIME, cursor.getString(cursor.getColumnIndex(NotesDB.TIME)));
intent.putExtra(NotesDB.VIDEO, cursor.getString(cursor.getColumnIndex(NotesDB.VIDEO)));
intent.putExtra(NotesDB.PATH, cursor.getString(cursor.getColumnIndex(NotesDB.PATH)));
startActivity(intent);
}
});
}
public void selectDB(){
Cursor cursor = dbReader.query(NotesDB.TABLE_NAME, null, null, null, null, null, null);
adapter = new MyAdapter(this,cursor);//呼叫介面卡頁面
lv.setAdapter(adapter);
}
@Override
public void onClick(View v) {
i = new Intent(this, AddContent.class);
switch (v.getId()) {
case R.id.text:
i.putExtra("flag", "1");
startActivity(i);
break;
case R.id.img:
i.putExtra("flag", "2");
startActivity(i);
break;
case R.id.video:
i.putExtra("flag", "3");
startActivity(i);
break;
}
}
//在onResume()中來實現資料庫的載入
@Override
protected void onResume() {
super.onResume();
selectDB();
}
}
介面卡頁面
package com.jikexueyuan.hellonotes;
import android.content.Context;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.media.ThumbnailUtils;
import android.provider.MediaStore;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
public class MyAdapter extends BaseAdapter {
private Context context;
private Cursor cursor;
private LinearLayout layout;
// 傳遞上下文環境context,以及指標給介面卡
public MyAdapter(Context context, Cursor cursor) {
this.context = context;
this.cursor = cursor;
}
@Override
public int getCount() {
return cursor.getCount();
}
@Override
public Object getItem(int position) {
return position;
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return 0;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
LayoutInflater inflater =LayoutInflater.from(context);//從當前 context中獲取佈局載入器
//LayoutInflater layout = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
layout = (LinearLayout)inflater.inflate(R.layout.cell, null);//載入xml檔案cell，成為當前的佈局
//從當前佈局中取出各個UI元件
TextView contentTv= (TextView)layout.findViewById(R.id.list_content);
TextView timeTv= (TextView)layout.findViewById(R.id.list_time);
ImageView imgIv= (ImageView)layout.findViewById(R.id.list_img);
ImageView videoIv= (ImageView)layout.findViewById(R.id.list_video);
cursor.moveToPosition(position);
String content = cursor.getString(cursor.getColumnIndex("content"));
String time = cursor.getString(cursor.getColumnIndex("time"));
String uri = cursor.getString(cursor.getColumnIndex("path"));
String uri_video = cursor.getString(cursor.getColumnIndex("video"));
contentTv.setText(content);
timeTv.setText(time);
videoIv.setImageBitmap(getVideoThumbnail(uri_video,200,200,MediaStore.Images.Thumbnails.MICRO_KIND));
imgIv.setImageBitmap(getImageThumbnail(uri,200,200));
return layout;
}
// 獲取相機照片的縮圖,直接獲取原始圖片會觸發系統 oom錯誤
public Bitmap getImageThumbnail(String uri, int width, int height) {
//72-75行是為了防止發生圖片過大導致記憶體溢位錯誤，用BitmapFactory.Options的方法，得到bitmap=要取出圖片的寬和高資訊
Bitmap bitmap = null;
BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
bitmap = BitmapFactory.decodeFile(uri, options);
options.inJustDecodeBounds = false;//取出bitmap資訊之後關閉options.inJustDecodeBounds,與上面成對出現
int beWidth = options.outWidth / width;
int beHeight = options.outHeight / height;
int be = 1;
if (beWidth < beHeight) {
be = beWidth;
} else {
be = beHeight;
}
if (be <= 0) {
be = 1;
}
options.inSampleSize = be;
bitmap = BitmapFactory.decodeFile(uri, options);//根據uri地址取出bitmap，同時options不為空時，這個bitmap將按照前面這隻的比例顯示
bitmap = ThumbnailUtils.extractThumbnail(bitmap, width, height,
ThumbnailUtils.OPTIONS_RECYCLE_INPUT);
return bitmap;
}
private Bitmap getVideoThumbnail(String uri, int width, int height, int kind) {
Bitmap bitmap = null;
bitmap = ThumbnailUtils.createVideoThumbnail(uri, kind);
bitmap = ThumbnailUtils.extractThumbnail(bitmap, width, height,
ThumbnailUtils.OPTIONS_RECYCLE_INPUT);
return bitmap;
}
}
新增資料頁面
package com.jikexueyuan.hellonotes;
import java.io.File;
import java.text.SimpleDateFormat;
import java.util.Date;
import android.app.Activity;
import android.content.ContentValues;
import android.content.Intent;
import android.database.sqlite.SQLiteDatabase;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.VideoView;
public class AddContent extends Activity implements OnClickListener {
private String val;
private Button savebtn, deletebtn;
private ImageView c_img;
private EditText ettext;
private VideoView v_video;
private NotesDB notesDB;
private SQLiteDatabase dbWriter;
private File phoneFile;
private File videoFile;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.addcontent);
val = getIntent().getStringExtra("flag");// 接受前面傳遞的按鈕型別
savebtn = (Button) findViewById(R.id.save);
deletebtn = (Button) findViewById(R.id.delete);
c_img = (ImageView) findViewById(R.id.c_img);
v_video = (VideoView) findViewById(R.id.c_video);
ettext = (EditText) findViewById(R.id.text);
savebtn.setOnClickListener(this);
deletebtn.setOnClickListener(this);
notesDB = new NotesDB(this);
dbWriter = notesDB.getWritableDatabase();
initView();
}
private void initView() {
if (val.equals("1")) {// 新增的是文字
c_img.setVisibility(View.GONE);
v_video.setVisibility(View.GONE);
}
if (val.equals("2")) {// 新增的是圖片
c_img.setVisibility(View.VISIBLE);
v_video.setVisibility(View.GONE);
Intent iimg = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);// 跳轉到系統相機
// /storage/emulated/0/2016年12月07日 02:19:49.jpg
phoneFile = new File(Environment.getExternalStorageDirectory()
.getAbsoluteFile() + "/" + getTime() + ".jpg");// 絕對路徑+圖片名稱
iimg.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(phoneFile));
Log.d("TAG", phoneFile + "");
startActivityForResult(iimg, 1);
}
if (val.equals("3")) {
c_img.setVisibility(View.GONE);
v_video.setVisibility(View.VISIBLE);
Intent video = new Intent(MediaStore.ACTION_VIDEO_CAPTURE);// 跳轉到系統相機
// /storage/emulated/0/2016年12月07日 02:19:49.jpg
videoFile = new File(Environment.getExternalStorageDirectory()
.getAbsoluteFile() + "/" + getTime() + ".mp4");// 絕對路徑+圖片名稱
video.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(videoFile));
Log.d("TAG", videoFile + "");
startActivityForResult(video, 2);
}
}
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.save:
addDB();
finish();
break;
case R.id.delete:
finish();
break;
}
}
public void addDB() {
ContentValues cv = new ContentValues();
cv.put(NotesDB.CONTENT, ettext.getText().toString());
cv.put(NotesDB.TIME, getTime());
Log.d("TAG", phoneFile+"");
cv.put(NotesDB.PATH, phoneFile+"");
cv.put(NotesDB.VIDEO, videoFile+"");
dbWriter.insert(NotesDB.TABLE_NAME, null, cv);
}
private String getTime() {
SimpleDateFormat format = new SimpleDateFormat("yyyy年MM月dd日 HH:mm:ss");
Date date = new Date();
String str = format.format(date);
return str;
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == 1) {
Bitmap bitmap = BitmapFactory.decodeFile(phoneFile
.getAbsolutePath());
c_img.setImageBitmap(bitmap);
}
if(requestCode ==2){
v_video.setVideoURI(Uri.fromFile(videoFile));
v_video.start();
}
}
}
幾個XML檔案
activity_main.xml
addcontent.xml
cell.xml頁面
select.xml