如何在SQLite数据库中存储图像

在我的应用程序中，我从图库上传图像，我想将这个图像存储在SQLite数据库。 如何在数据库中存储位图？ 我将位图转换为字符串并将其保存在数据库中。 从数据库中检索它时，我无法将该字符串分配给ImageView，因为它是一个字符串。

Imageupload12 .java：

public class Imageupload12 extends Activity { Button buttonLoadImage; ImageView targetImage; int i = 0; Database database = new Database(this); String i1; String img; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main5); buttonLoadImage = (Button) findViewById(R.id.loadimage); targetImage = (ImageView) findViewById(R.id.targetimage); Bundle b = getIntent().getExtras(); if (b != null) { img = b.getString("image"); targetImage2.setImageURI("image"); //i am getting error as i cant assign string to imageview. } buttonLoadImage.setOnClickListener(new Button.OnClickListener() { public void onClick(View arg0) { // TODO Auto-generated method stub Intent intent = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI); Log.i("photo", "" + intent); startActivityForResult(intent, i); i = i + 1; } }); } @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { // TODO Auto-generated method stub super.onActivityResult(requestCode, resultCode, data); switch (requestCode) { case 0: if (resultCode == RESULT_OK) { Uri targetUri = data.getData(); // textTargetUri.setText(targetUri.toString()); Bitmap bitmap; try { bitmap = BitmapFactory.decodeStream(getContentResolver().openInputStream(targetUri)); targetImage.setImageBitmap(bitmap); i1 = bitmap.toString(); Log.i("firstimage........", "" + i1); targetImage.setVisibility(0); SQLiteDatabase db = database.getWritableDatabase(); db.execSQL("INSERT INTO UPLOAD VALUES('" + i1 + "');"); } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } } break; } } } 

Image.class：

 public class Image extends Activity { Database database = new Database(this); static EfficientAdapter adapter, adapter1; static ListView lv1; static SQLiteDatabase db; static EfficientAdapter adp; static Cursor c1; static Vector < String > IMAGE = new Vector < String > (); @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); db = database.getReadableDatabase(); c1 = db.rawQuery("select * from UPLOAD;", null); if (c1.moveToFirst()) { do { IMAGE.add(c1.getString(0).toString()); } while (c1.moveToNext()); c1.close(); } lv1 = (ListView) findViewById(R.id.List); adapter = new EfficientAdapter(this); lv1.setAdapter(adapter); ImageView add = (ImageView) findViewById(R.id.imv1a); add.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub IMAGE.clear(); Intent i = new Intent(Image.this, Imageupload12.class); startActivity(i); } }); } private static class EfficientAdapter extends BaseAdapter { // protected final Context Context = null; protected LayoutInflater mLayoutInflater; AlertDialog.Builder aBuilder; public EfficientAdapter(Context context) { // TODO Auto-generated constructor stub mLayoutInflater = LayoutInflater.from(context); } @Override public int getCount() { // TODO Auto-generated method stub return IMAGE.size(); } @Override public Object getItem(int position) { // TODO Auto-generated method stub return position; } @Override public long getItemId(int position) { // TODO Auto-generated method stub return position; } @Override public View getView(final int position, View convertView, ViewGroup parent) { // TODO Auto-generated method stub final ViewHolder mVHolder; if (convertView == null) { convertView = mLayoutInflater.inflate(R.layout.pjtlistdetails, parent, false); mVHolder = new ViewHolder(); mVHolder.t1 = (TextView) convertView.findViewById(R.id.pjtdetails); mVHolder.time = (TextView) convertView.findViewById(R.id.name); mVHolder.imv = (ImageButton) convertView.findViewById(R.id.editic); mVHolder.imvd = (ImageView) convertView.findViewById(R.id.delete); mVHolder.imvf = (ImageView) convertView.findViewById(R.id.fwd); mVHolder.imv.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { String img = IMAGE.elementAt(position); Log.i("image...", "" + img); Context ctx = v.getContext(); Intent myIntent = new Intent(); ctx = v.getContext(); myIntent.setClass(ctx, Imageupload12.class); myIntent.putExtra("image", img); ctx.startActivity(myIntent); IMAGE.clear(); } }); static class ViewHolder { ImageButton imv; ImageView imvd, imvf; } } } } } 

Answer 1

你必须使用“blob”来存储图像。

例如：将图像存储到数据库中

 public void insertImg(int id , Bitmap img ) { byte[] data = getBitmapAsByteArray(img); // this is a function insertStatement_logo.bindLong(1, id); insertStatement_logo.bindBlob(2, data); insertStatement_logo.executeInsert(); insertStatement_logo.clearBindings() ; } public static byte[] getBitmapAsByteArray(Bitmap bitmap) { ByteArrayOutputStream outputStream = new ByteArrayOutputStream(); bitmap.compress(CompressFormat.PNG, 0, outputStream); return outputStream.toByteArray(); } 

从数据库检索图像

 public Bitmap getImage(int i){ String qu = "select img from table where feedid=" + i ; Cursor cur = db.rawQuery(qu, null); if (cur.moveToFirst()){ byte[] imgByte = cur.getBlob(0); cur.close(); return BitmapFactory.decodeByteArray(imgByte, 0, imgByte.length); } if (cur != null && !cur.isClosed()) { cur.close(); } return null ; } 

Answer 2

使用blob将你的图像存储在你的sqlite数据库。 下面是如何使用blob的例子。

设置数据库

 CREATE TABLE " + DB_TABLE + "("+ KEY_NAME + " TEXT," + KEY_IMAGE + " BLOB);"; 

插入数据库：

 public void addEntry( String name, byte[] image) throws SQLiteException{ ContentValues cv = new ContentValues(); cv.put(KEY_NAME, name); cv.put(KEY_IMAGE, image); database.insert( DB_TABLE, null, cv ); } 

检索数据 ：

  byte[] image = cursor.getBlob(1); 

注意：

1. 在插入数据库之前，您需要先将您的位图图像转换为字节数组，然后将其应用于数据库查询。
2. 当从数据库中检索时，你肯定有一个字节数组的图像，你需要做的是将字节数组转换回原始图像。 所以，你必须利用BitmapFactory解码。

下面是一个工具类，我希望可以帮助你：

 public class DbBitmapUtility { // convert from bitmap to byte array public static byte[] getBytes(Bitmap bitmap) { ByteArrayOutputStream stream = new ByteArrayOutputStream(); bitmap.compress(CompressFormat.PNG, 0, stream); return stream.toByteArray(); } // convert from byte array to bitmap public static Bitmap getImage(byte[] image) { return BitmapFactory.decodeByteArray(image, 0, image.length); } } 

Answer 3

我相信将图像存储到SQLLite数据库的最佳方式是使用Base 64算法。 它将图像转换为纯文本并再次返回。 您可以在http://developersfound.com/Base64FromStream.zip下载完整的示例Android项目。; 该程序不存储图像，但它将图像从图像转换为文本，然后再转换回来。

这是班级：

 package com.example.TestProject; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.util.Base64; import android.util.Log; import java.io.*; import java.net.URL; import java.net.URLConnection; import java.nio.channels.FileChannel; public class Base64CODEC { private int IO_BUFFER_SIZE = 64; //private int IO_BUFFER_SIZE = 8192; private URL urlObject = null; private URLConnection myConn = null; ByteArrayOutputStream os = null; public void Base64CODEC() {} public Bitmap Base64ImageFromURL(String url) { Bitmap bitmap = null; InputStream in = null; BufferedOutputStream out = null; try { urlObject = new URL(url); myConn = urlObject.openConnection(); in = myConn.getInputStream(); final ByteArrayOutputStream dataStream = new ByteArrayOutputStream(); out = new BufferedOutputStream(dataStream, IO_BUFFER_SIZE); copyCompletely(in, out); final byte[] data = dataStream.toByteArray(); BitmapFactory.Options options = new BitmapFactory.Options(); bitmap = BitmapFactory.decodeByteArray(data, 0, data.length, options); } catch (IOException e) { Log.e("TAG", "Could not load Bitmap from: " + url); } finally { //closeStream(in); try { in.close(); } catch (IOException e) { e.printStackTrace(); //To change body of catch statement use File | Settings | File Templates. } //closeStream(out); try { out.close(); } catch (IOException e) { e.printStackTrace(); //To change body of catch statement use File | Settings | File Templates. } } return bitmap; } private void copyCompletely(InputStream input, OutputStream output) throws IOException { // if both are file streams, use channel IO if ((output instanceof FileOutputStream) && (input instanceof FileInputStream)) { try { FileChannel target = ((FileOutputStream) output).getChannel(); FileChannel source = ((FileInputStream) input).getChannel(); source.transferTo(0, Integer.MAX_VALUE, target); source.close(); target.close(); return; } catch (Exception e) { /* failover to byte stream version */ } } byte[] buf = new byte[8192]; while (true) { int length = input.read(buf); if (length < 0) break; output.write(buf, 0, length); } try { input.close(); } catch (IOException ignore) { } try { output.close(); } catch (IOException ignore) {} } public String convertToBase64(Bitmap bitmap) { ByteArrayOutputStream os = new ByteArrayOutputStream(); bitmap.compress(Bitmap.CompressFormat.PNG,100,os); byte[] byteArray = os.toByteArray(); return Base64.encodeToString(byteArray, 0); } public Bitmap convertToBitmap(String base64String) { byte[] decodedString = Base64.decode(base64String, Base64.DEFAULT); Bitmap bitmapResult = BitmapFactory.decodeByteArray(decodedString, 0, decodedString.length); return bitmapResult; } } 

这里是使用这个类的主要活动：

 package com.example.TestProject; import android.app.Activity; import android.graphics.Bitmap; import android.os.Bundle; import android.os.Handler; import android.os.Message; import android.view.View; import android.widget.ImageView; public class MainActivity extends Activity implements Runnable { private Thread thread = null; private Bitmap bitmap = null; private Base64CODEC base64CODEC = null; private ImageView imgViewSource = null; private ImageView imgViewDestination = null; private boolean isSourceImageVisible = false; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); } public void CmdLoadImage_Click(View view) { try { if(isSourceImageVisible == true) { imgViewSource.setImageBitmap(null); imgViewDestination.setImageBitmap(null); isSourceImageVisible = false; } else { base64CODEC = new Base64CODEC(); thread = new Thread(this); thread.start(); } } catch (NullPointerException e) {} } public void CmdEncodeImage_Click(View view) { Base64CODEC base64CODEC = new Base64CODEC(); try { String base64String = base64CODEC.convertToBase64(bitmap); imgViewDestination = (ImageView) findViewById(R.id.imgViewDestination); Bitmap imgViewDestinationBitmap = base64CODEC.convertToBitmap(base64String); imgViewDestination.setImageBitmap(imgViewDestinationBitmap); } catch (NullPointerException e) { // } } @Override public void run() { bitmap = base64CODEC.Base64ImageFromURL("http://developersfound.com/me.png"); handler.sendEmptyMessage(0); } private Handler handler = new Handler() { @Override public void handleMessage(Message msg) { imgViewSource = (ImageView) findViewById(R.id.imgViewSource); imgViewSource.setImageBitmap(bitmap); isSourceImageVisible = true; thread = null; } }; } 

Answer 4

要在sqlite数据库中存储任何图像，您需要将该图像存储在字节数组而不是字符串中。 将该图像转换为字节数组并将该字节[]存储到数据库。 当检索该图像时，您将获得byte []将该字节[]转换为位图，从而获得原始图像。

Answer 5

我有两件事需要注意。 如何从图库中存储图像，以及如何从uri存储图像（www.example.com/myimage.png）

如何从图库中存储图像

从Uri数据类型的库通知中检索图像。 为了将图像存储到android SQLite数据库，您需要将图像uri转换为位图，然后转换为二进制字符即字节[]序列。 然后将表列数据类型设置为BLOB数据类型。 从DB获取图像后，将字节[]数据类型转换为位图以将其设置为imageview。

如何存储来自uri的图像。

请注意，您可以将图像以uri字符串的形式存储在数据库中，但只能从网站的图像uri中存储。 将uri转换为字符串并将其插入到数据库中。 以字符串形式检索图像uri，并将其转换为uri数据类型，以便将其设置为imageview。

你可以尝试这个职位工作的程序和源代码如何存储图像在Sqlite数据库和显示在列表视图