用sqlite存储Android手机图片,再从数据库读出图片显示。

用sqlite存储Android手机图片,再从数据库读出图片显示。,第1张

概述废话不多说,直接粘贴代码上来首先建一个数据库类: import android.content.Context;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteDatabase.CursorFactory;import android.database.sqlite.SQLi
废话不多说,直接粘贴代码上来首先建一个数据库类:
 
import androID.content.Context;import androID.database.sqlite.sqliteDatabase;import androID.database.sqlite.sqliteDatabase.CursorFactory;import androID.database.sqlite.sqliteOpenHelper;public class Helpersave extends sqliteOpenHelper{	public Helpersave(Context context,String name,CursorFactory factory,int version) {		super(context,name,factory,version);		// Todo auto-generated constructor stub			}	public Helpersave(Context context) {		// Todo auto-generated constructor stub		super(context,"SaveImageDemo",null,1);//这个构造器必须有,activity里会调用;	}	@OverrIDe	public voID onCreate(sqliteDatabase jb) {		// Todo auto-generated method stub		jb.execsql("create table image(image_ID integer primary key,bit_image BLOB)");	}	@OverrIDe	public voID onUpgrade(sqliteDatabase db,int oldVersion,int newVersion) {		// Todo auto-generated method stub			}	}</span>
activity:
<span >package com.example.sampleadapterdemo;import java.io.ByteArrayOutputStream;import java.io.inputStream;import java.util.ArrayList;import java.util.HashMap;import java.util.List;import java.util.Map;import androID.app.Activity;import androID.content.ContentValues;import androID.content.Intent;import androID.database.Cursor;import androID.database.sqlite.sqliteDatabase;import androID.database.sqlite.sqliteOpenHelper;import androID.graphics.Bitmap;import androID.graphics.BitmapFactory;import androID.net.Uri;import androID.nfc.Tag;import androID.os.Bundle;import androID.provIDer.MediaStore;import androID.util.Log;import androID.vIEw.VIEw;import androID.Widget.button;import androID.Widget.ImageVIEw;import androID.Widget.ListVIEw;import androID.Widget.SimpleAdapter;public class MainActivity extends Activity {	private static int RESulT_LOAD_IMAGE;	private static final String TAG = "Result";	MyHelper helper;	sqliteDatabase db;	Cursor cursor;	private ListVIEw ListVIEw =null;	private SimpleAdapter adapter ;	private button but1;	private button but2;	private ImageVIEw Image;	private List<Map<String,Object>> List = new ArrayList<Map<String,Object>>();	@OverrIDe	protected voID onCreate(Bundle savedInstanceState) {		super.onCreate(savedInstanceState);		setContentVIEw(R.layout.activity_main);		Image = (ImageVIEw) findVIEwByID(R.ID.Image1);		but1 = (button) super.findVIEwByID(R.ID.but1);		but2 = (button) super.findVIEwByID(R.ID.but2);		but2.setonClickListener(new VIEw.OnClickListener() {						@OverrIDe			public voID onClick(VIEw v) {				// Todo auto-generated method stub				db = helper.getWritableDatabase();				cursor = db.query("image",null);				if (cursor.movetoFirst()) {				   // byte[] —> Bitmap				   byte[] bytes = cursor.getBlob(cursor.getColumnIndex("bit_image"));				   Bitmap bitmap = BitmapFactory.decodeByteArray(bytes,bytes.length,null);				   Image.setimageBitmap(bitmap);				   cursor.close();					db.close();					helper.close();				}			}		});		but1.setonClickListener(new VIEw.OnClickListener() {						@OverrIDe			public voID onClick(VIEw v) {				// Todo auto-generated method stub				//一个重定向打开系统图库				Intent i = new Intent(						Intent.ACTION_PICK,androID.provIDer.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);						startActivityForResult(i,RESulT_LOAD_IMAGE);			}		});		ListVIEw=(ListVIEw) super.findVIEwByID(R.ID.ListvIEw1);		String str1="001";		Object image1 =R.drawable.food_image;		Map<String,Object> map = new HashMap<String,Object>();		map.put(str1,image1);		List.add(map);		adapter = new SimpleAdapter(getApplicationContext(),List,R.layout.List,new String[]{str1},new int[]{R.ID.image});		ListVIEw.setAdapter(adapter);	}	@OverrIDe	protected voID onActivityResult(int requestCode,int resultCode,Intent data) {		// Todo auto-generated method stub		super.onActivityResult(requestCode,resultCode,data);		if (requestCode == RESulT_LOAD_IMAGE && resultCode == RESulT_OK && null != data) {            Uri selectedImage = data.getData();            String[] filePathColumn = { MediaStore.Images.Media.DATA };              cursor = getContentResolver().query(selectedImage,filePathColumn,null);            cursor.movetoFirst();              int columnIndex = cursor.getColumnIndex(filePathColumn[0]);            String picturePath = cursor.getString(columnIndex);            cursor.close();            Log.d(TAG,"已经得到bitmap");                        //Image.setimageBitmap(BitmapFactory.decodefile(picturePath));                        //从手机选择图片插入数据库                       Bitmap bitmap = BitmapFactory.decodefile(picturePath);                          byte[] by = bitmapToBytes(bitmap);                                   //cursor = db.query("image",null);            ContentValues values = new ContentValues();                    values.put("image_ID",17);                     values.put("bit_image",by);                                                          db = helper.getWritableDatabase();                    db.insert("image",values);//插入数据                		db.close();    	    		helper.close();    			 						}		}	       		 public static byte[] bitmapToBytes(Bitmap bitmap){         if (bitmap == null) {            return null;         }         final ByteArrayOutputStream os = new ByteArrayOutputStream();         // 将Bitmap压缩成PNG编码,质量为100%存储         bitmap.compress(Bitmap.CompressFormat.JPEG,100,os);//除了PNG还有很多常见格式,如jpeg等。         return os.toByteArray();        }       	}</span>


最后布局文件:

<span ><linearLayout xmlns:androID="http://schemas.androID.com/apk/res/androID"    androID:layout_wIDth="match_parent"    androID:layout_height="match_parent"    androID:orIEntation="vertical"     >    <TextVIEw        androID:layout_wIDth="wrap_content"        androID:layout_height="wrap_content"        androID:text="@string/hello_world"         androID:visibility="gone"/>    <button         androID:ID="@+ID/butopen"        androID:layout_wIDth="match_parent"        androID:layout_height="wrap_content"/>    <button         androID:ID="@+ID/butsave"        androID:layout_height="wrap_content"        androID:layout_wIDth="match_parent"        />    <button         androID:ID="@+ID/butshow"        androID:layout_height="wrap_content"        androID:layout_wIDth="match_parent"/>	<ImageVIEw 	    androID:ID="@+ID/Image"	    androID:layout_height="wrap_content"	    androID:layout_wIDth="wrap_content"	    />	<ImageVIEw 	    androID:ID="@+ID/imageshow"	    androID:layout_height="wrap_content"	    androID:layout_wIDth="wrap_content"/></linearLayout></span>
总结

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