Android文件图片上传的详细讲解（三）---模式回调类

package com.easyway.fileupload;

import android.app.Activity;
import android.app.AlertDialog;
import android.app.Dialog;
import android.content.ContentResolver;
import android.content.DialogInterface;
import android.content.Intent;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
/**
 * Activity 上传的界面
 * 
 * @Title: 
 * @Description: 实现TODO
 * @Copyright:Copyright (c) 2011
 * @Company:易程科技股份有限公司
 * @Date:2012-7-2
 * @author  longgangbai
 * @version 1.0
 */
public class AndroidUploadFilesActivity extends Activity implements OnClickListener{
 private static final String TAG = "uploadImage";
 
 private Button selectImage,uploadImage;
 private ImageView imageView;
 
 private String picPath = null;
 
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        selectImage = (Button) this.findViewById(R.id.selectImage);
        uploadImage = (Button) this.findViewById(R.id.uploadImage);
        selectImage.setOnClickListener(this);
        uploadImage.setOnClickListener(this);
        
        imageView = (ImageView) this.findViewById(R.id.imageView);
        
        
    }
    
 @Override
 public void onClick(View v) {
  switch (v.getId()) {
  case R.id.selectImage:
   /***
    * 这个是调用android内置的intent，来过滤图片文件   ，同时也可以过滤其他的  
    */
   Intent intent = new Intent();
   intent.setType("image/*");
   intent.setAction(Intent.ACTION_GET_CONTENT);
   //回调图片类使用的
   startActivityForResult(intent, RESULT_CANCELED);
   break;
  case R.id.uploadImage:
   if(picPath!=null&&picPath.length()>0)
   {
    UploadFileTask uploadFileTask=new UploadFileTask(this);
    uploadFileTask.execute(picPath);
   }
   break;
  default:
   break;
  }
 }

 /**
  * 回调执行的方法
  */
 @Override
 protected void onActivityResult(int requestCode, int resultCode, Intent data) {
  if(resultCode==Activity.RESULT_OK)
  {
   /**
    * 当选择的图片不为空的话，在获取到图片的途径  
    */
   Uri uri = data.getData();
   Log.e(TAG, "uri = "+ uri);
   try {
    String[] pojo = {MediaStore.Images.Media.DATA};
    
    Cursor cursor = managedQuery(uri, pojo, null, null,null);
    if(cursor!=null)
    {
     ContentResolver cr = this.getContentResolver();
     int colunm_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
     cursor.moveToFirst();
     String path = cursor.getString(colunm_index);
     /***
      * 这里加这样一个判断主要是为了第三方的软件选择，比如：使用第三方的文件管理器的话，你选择的文件就不一定是图片了，这样的话，我们判断文件的后缀名
      * 如果是图片格式的话，那么才可以   
      */
     if(path.endsWith("jpg")||path.endsWith("png"))
     {
      picPath = path;
      Bitmap bitmap = BitmapFactory.decodeStream(cr.openInputStream(uri));
      imageView.setImageBitmap(bitmap);
     }else{
      alert();
     }
    }else{
     alert();
    }
    
   } catch (Exception e) {
    e.printStackTrace();
   }
  }
  
  /**
   * 回调使用
   */
  super.onActivityResult(requestCode, resultCode, data);
 }
 
 private void alert()
    {
     Dialog dialog = new AlertDialog.Builder(this)
  .setTitle("提示")
  .setMessage("您选择的不是有效的图片")
  .setPositiveButton("确定",
    new DialogInterface.OnClickListener() {
     public void onClick(DialogInterface dialog,
       int which) {
      picPath = null;
     }
    })
  .create();
  dialog.show();
    }

}