1Android调用系统图库2读写文件

package com.example.demo;

import android.app.Activity;
import android.content.Intent;
import android.database.Cursor;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;

public class MainActivity extends Activity {
    
	
	private static int RESULT_LOAD_IMAGE = 1;
	
	/** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        Button buttonLoadImage = (Button) findViewById(R.id.buttonLoadPicture);
        buttonLoadImage.setOnClickListener(new View.OnClickListener() {
			
			@Override
			public void onClick(View arg0) {
				
				Intent i = new Intent(
						Intent.ACTION_PICK,
						android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
				
				startActivityForResult(i, RESULT_LOAD_IMAGE);
			}
		});
    }
    
    
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    	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 cursor = getContentResolver().query(selectedImage,
					filePathColumn, null, null, null);
			cursor.moveToFirst();

			int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
			String picturePath = cursor.getString(columnIndex);
			cursor.close();
			
			ImageView imageView = (ImageView) findViewById(R.id.imgView);
			imageView.setImageBitmap(BitmapFactory.decodeFile(picturePath));
		
		}
    
    
    }
}

package com.gula.tools;

import java.io.FileInputStream;
import java.io.FileOutputStream;

import org.apache.http.util.EncodingUtils;

import android.content.Context;

public class FileCommon {
	Context context;

	public FileCommon(Context context) {
		this.context = context;
	}

	public void writeFileData(String fileName, String message) {

		try {

			FileOutputStream fout = context.openFileOutput(fileName,
					Context.MODE_PRIVATE);

			byte[] bytes = message.getBytes();

			fout.write(bytes);

			fout.close();

		}

		catch (Exception e) {

			e.printStackTrace();

		}

	}public String readFileData(String fileName){ 
 
        String res=""; 
 
        try{ 
 
         FileInputStream fin = context.openFileInput(fileName); 
 
         int length = fin.available(); 
 
         byte [] buffer = new byte[length]; 
 
         fin.read(buffer);     
 
         res = EncodingUtils.getString(buffer, "UTF-8"); 
 
         fin.close();     
 
        } 
 
        catch(Exception e){ 
 
         e.printStackTrace(); 
 
        } 
 
        return res; 
 
    }   


}