sharepreference方式保存带图片的例子

goman · 发表于 2013-8-28 16:29

2

通常，Sharepreference方式保存数据只能保存简单类型的数据，对于像图片等，就需要对这些数据进行编码，然后将编码后的数据按字符串的形式保存到xml中去。

本项目需要用到一个第三方的jar包（common-codec-1.4.jar）

在选择图片的时候我们采用画廊视图来选择一张图片。

核心代码如下：

package net.blogjava.mobile;

import java.io.ByteArrayInputStream;

import java.io.ByteArrayOutputStream;

import java.io.ObjectInputStream;

import java.io.ObjectOutputStream;

import java.lang.reflect.Field;

import java.util.ArrayList;

import java.util.List;

import org.apache.commons.codec.binary.Base64;

import android.app.Activity;

import android.app.AlertDialog;

import android.content.Context;

import android.content.DialogInterface;

import android.content.SharedPreferences;

import android.content.res.TypedArray;

import android.graphics.Bitmap.CompressFormat;

import android.graphics.drawable.BitmapDrawable;

import android.graphics.drawable.Drawable;

import android.os.Bundle;

import android.view.View;

import android.view.View.OnClickListener;

import android.view.ViewGroup;

import android.widget.BaseAdapter;

import android.widget.Button;

import android.widget.EditText;

import android.widget.Gallery;

import android.widget.ImageView;

public class Main extends Activity implements OnClickListener

{

private SharedPreferences mySharedPreferences;

private EditText etProductID;

private EditText etProductName;

private EditText etProductPrice;

private ImageView imageView;

private List<Integer> imageResIdList = new ArrayList<Integer>();

public class ImageAdapter extends BaseAdapter

{

int mGalleryItemBackground;

private Context mContext;

public ImageAdapter(Context context)

{

mContext = context;

TypedArray typedArray = obtainStyledAttributes(R.styleable.Gallery1);

mGalleryItemBackground = typedArray.getResourceId(

R.styleable.Gallery1_android_galleryItemBackground, 0);

}

public int getCount()

{

return imageResIdList.size();

}

public Object getItem(int position)

{

return position;

}

public long getItemId(int position)

{

return position;

}

public View getView(int position, View convertView, ViewGroup parent)

{

ImageView imageView = new ImageView(mContext);

imageView.setImageResource(imageResIdList.get(position));

imageView.setScaleType(ImageView.ScaleType.FIT_XY);

imageView.setLayoutParams(new Gallery.LayoutParams(136, 88));

imageView.setBackgroundResource(mGalleryItemBackground);

return imageView;

}

@Override

public void onClick(View view)

{

try

{

switch (view.getId())

{

case R.id.btnSave:

Product product = new Product();

product.setId(etProductID.getText().toString());

product.setName(etProductName.getText().toString());

product.setPrice(Float.parseFloat(etProductPrice.getText()

.toString()));

ByteArrayOutputStream baos = new ByteArrayOutputStream();

ObjectOutputStream oos = new ObjectOutputStream(baos);

oos.writeObject(product);

mySharedPreferences = getSharedPreferences("base64",

Activity.MODE_PRIVATE);

String productBase64 = new String(Base64.encodeBase64(baos

.toByteArray()));

SharedPreferences.Editor editor = mySharedPreferences

.edit();

editor.putString("product", productBase64);

baos = new ByteArrayOutputStream();

((BitmapDrawable) imageView.getDrawable()).getBitmap()

.compress(CompressFormat.JPEG, 50, baos);

String imageBase64 = new String(Base64.encodeBase64(baos

.toByteArray()));

editor.putString("productImage", imageBase64);

editor.commit();

oos.close();

new AlertDialog.Builder(this).setTitle("保存成功.")

.setPositiveButton("确定", null).show();

break;

case R.id.btnSelectImage:

View myView = getLayoutInflater().inflate(R.layout.gallery,

null);

final Gallery gallery = (Gallery) myView

.findViewById(R.id.gallery);

ImageAdapter imageAdapter = new ImageAdapter(this);

gallery.setAdapter(imageAdapter);

new AlertDialog.Builder(this)

.setTitle("选择产品图像")

.setView(myView)

.setPositiveButton(

"确定",

new android.content.DialogInterface.OnClickListener()

{

@Override

public void onClick(

DialogInterface dialog,

int which)

{

imageView

.setImageResource(imageResIdList

.get(gallery

.getSelectedItemPosition()));

}

}).setNegativeButton("取消", null).show();

break;

}

catch (Exception e)

{

setTitle("error:" + e.getMessage());

}

@Override

public void onCreate(Bundle savedInstanceState)

{

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

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

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

etProductID = (EditText) findViewById(R.id.etProductID);

etProductName = (EditText) findViewById(R.id.etProductName);

etProductPrice = (EditText) findViewById(R.id.etProductPrice);

imageView = (ImageView) findViewById(R.id.imageview);

btnSave.setOnClickListener(this);

btnSelectImage.setOnClickListener(this);

byte[] base64Bytes;

ByteArrayInputStream bais;

try

{

mySharedPreferences = getSharedPreferences("base64",

Activity.MODE_PRIVATE);

String productBase64 = mySharedPreferences.getString("product", "");

base64Bytes = Base64.decodeBase64(productBase64.getBytes());

bais = new ByteArrayInputStream(base64Bytes);

ObjectInputStream ois = new ObjectInputStream(bais);

Product product = (Product) ois.readObject();

etProductID.setText(product.getId());

etProductName.setText(product.getName());

etProductPrice.setText(String.valueOf(product.getPrice()));

ois.close();

}

catch (Exception e)

{

}

try

{

String imageBase64 = mySharedPreferences.getString("productImage",

"");

base64Bytes = Base64.decodeBase64(imageBase64.getBytes());

bais = new ByteArrayInputStream(base64Bytes);

imageView.setImageDrawable(Drawable.createFromStream(bais,

"product_image"));

Field[] fields = R.drawable.class.getDeclaredFields();

for (Field field : fields)

{

if (!"icon".equals(field.getName()))

imageResIdList.add(field.getInt(R.drawable.class));

}

catch (Exception e)

{

// TODO: handle exception

}

</div

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sharepreference方式保存带图片的例子

sharepreference方式保存带图片的例子

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