Android实现相册中图片上传或下载

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:tools="http://schemas.android.com/tools"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  tools:context=".MainActivity"  
 
 <ImageView 
   android:id="@+id/ivHead"
   android:layout_marginTop="20dp"
   android:layout_centerHorizontal="true"
   android:layout_width="150dp"
   android:layout_height="150dp"/ 
 
 <Button
   android:id="@+id/btnSelectImage"
   android:layout_width="match_parent"
   android:layout_height="wrap_content"
   android:layout_alignParentLeft="true"
   android:layout_below="@+id/ivHead"
   android:layout_marginTop="16dp"
   android:text="打开相册" / 
 
 <Button
   android:id="@+id/btnDownloadImage"
   android:layout_width="match_parent"
   android:layout_height="wrap_content"
   android:layout_alignParentLeft="true"
   android:layout_below="@+id/btnSelectImage"
   android:text="下载图片" / 
 
 <ImageView
   android:id="@+id/ivDownload"
   android:layout_width="150dp"
   android:layout_height="150dp"
   android:layout_marginTop="20dp"
   android:layout_centerHorizontal="true"
   android:layout_below="@+id/btnDownloadImage" / 
 
</RelativeLayout 

package com.example.text;
import java.io.File;
import cn.bmob.v3.Bmob;
import cn.bmob.v3.BmobQuery;
import cn.bmob.v3.datatype.BmobFile;
import cn.bmob.v3.listener.DownloadFileListener;
import cn.bmob.v3.listener.GetListener;
import cn.bmob.v3.listener.UploadBatchListener;
import cn.bmob.v3.listener.UploadFileListener;
import com.android.volley.toolbox.ImageLoader;
import com.example.text.MainActivity;
import entity.Person;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.app.Activity;
import android.content.Intent;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;
public class MainActivity extends Activity implements OnClickListener {
private ImageView ivHead, ivDownload;
private Button btnSelectImage, btnDownloadImage;
private static final int IMAGE_CODE = 0;// 打开相册
private static final int RESIZE_CODE = 2;// 调整大小
private static final String IMAGE_NAME = " ";// 图片字符串
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Bmob.initialize(this, "8ef8a4752f48682eadb32d3c8c8e398f");// 初始化Bmob
// 初始化控件
init();
// 绑定点击事件
bindClick();
}
// 初始化控件
private void init() {
ivHead = (ImageView) findViewById(R.id.ivHead);
ivDownload = (ImageView) findViewById(R.id.ivDownload);
btnSelectImage = (Button) findViewById(R.id.btnSelectImage);
btnDownloadImage = (Button) findViewById(R.id.btnDownloadImage);
}
// 绑定点击事件
private void bindClick() {
btnSelectImage.setOnClickListener(this);
btnDownloadImage.setOnClickListener(this);
}
@Override
public void onClick(View view) {
switch (view.getId()) {
case R.id.btnSelectImage:
Intent galleryIntent = new Intent(Intent.ACTION_GET_CONTENT);
galleryIntent.addCategory(Intent.CATEGORY_OPENABLE);
galleryIntent.setType("image/*");//图片
startActivityForResult(galleryIntent, IMAGE_CODE);  //跳转，传递打开相册请求码
break;
case R.id.btnDownloadImage:
BmobQuery<Person  query=new BmobQuery<Person ();
query.getObject(this,"ef292ff6ef",new GetListener<Person () { //第二个参数为想要下载的BmobFile数据的objectId
@Override
public void onSuccess(Person person) {
Toast.makeText(MainActivity.this,"获取成功",Toast.LENGTH_SHORT).show();
//下载图片
downloadImage(person);
}
@Override
public void onFailure(int arg0, String arg1) {
Toast.makeText(MainActivity.this,"获取失败",Toast.LENGTH_SHORT).show();
}
});
break;
default:
break;
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (resultCode != RESULT_OK) {
return;
} else {
switch (requestCode) {
case IMAGE_CODE:
Uri uri = data.getData();
resizeImage(uri);
// 将获取到的uri转换为String型
String[] images = { MediaStore.Images.Media.DATA };// 将图片URI转换成存储路径
Cursor cursor = this
.managedQuery(uri, images, null, null, null);
int index = cursor
.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
cursor.moveToFirst();
String img_url = cursor.getString(index);
upload(img_url);
break;
case RESIZE_CODE:
if (data != null) {
showResizeImage(data);
}
break;
}
}
super.onActivityResult(requestCode, resultCode, data);
}
// 判断SD卡是否存在
private boolean isSdcardExisting() {
final String state = Environment.getExternalStorageState();
if (state.equals(Environment.MEDIA_MOUNTED)) {
return true;
} else {
return false;
}
}
// 重塑图片大小
public void resizeImage(Uri uri) {
Intent intent = new Intent("com.android.camera.action.CROP");
intent.setDataAndType(uri, "image/*");
intent.putExtra("crop", "true");// 可以裁剪
intent.putExtra("aspectX", 1);
intent.putExtra("aspectY", 1);
intent.putExtra("outputX", 150);
intent.putExtra("outputY", 150);
intent.putExtra("return-data", true);
startActivityForResult(intent, RESIZE_CODE);// 跳转，传递调整大小请求码
}
// 获取路径
private Uri getImageUri() {
return Uri.fromFile(new File(Environment.getExternalStorageDirectory(),
IMAGE_NAME));
}
// 显示图片
private void showResizeImage(Intent data) {
Bundle extras = data.getExtras();
if (extras != null) {
Bitmap photo = extras.getParcelable("data");
Drawable drawable = new BitmapDrawable(photo);
ivHead.setImageDrawable(drawable);
}
}
// 图片上传
private void upload(String imgpath) {
final BmobFile icon = new BmobFile(new File(imgpath));
icon.upload(this, new UploadFileListener() {
@Override
public void onSuccess() {
Person person = new Person();
person.setIcon(icon);
person.save(MainActivity.this);
Toast.makeText(MainActivity.this,"图片上传成功",Toast.LENGTH_SHORT).show();
}
@Override
public void onFailure(int arg0, String arg1) {
Toast.makeText(MainActivity.this,"图片上传失败",Toast.LENGTH_SHORT).show();
}
});
}
//下载图片
private void downloadImage(Person person) {
BmobFile icon=person.getIcon();
icon.download(MainActivity.this,new DownloadFileListener() {
@Override
public void onSuccess(String url) {
ivDownload.setImageBitmap(BitmapFactory.decodeFile(url));  //根据地址解码并显示图片
}
@Override
public void onFailure(int arg0, String arg1) {
Toast.makeText(MainActivity.this,"下载失败",Toast.LENGTH_SHORT).show();
}
});
}
}

package entity;
import cn.bmob.v3.BmobObject;
import cn.bmob.v3.datatype.BmobFile;
public class Person extends BmobObject{
private BmobFile icon;
public BmobFile getIcon() {
return icon;
}
public void setIcon(BmobFile icon) {
this.icon = icon;
}
}

<?xml version="1.0" encoding="utf-8"? 
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.text"
android:versionCode="1"
android:versionName="1.0"  
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="18" / 
<uses-permission android:name="android.permission.WRITE_CONTACTS"/ 
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/ 
<uses-permission android:name="android.permission.INTERNET"/ 
<!-- 允许联网 -- 
<uses-permission android:name="android.permission.INTERNET" / 
<!-- 获取GSM（2g）、WCDMA（联通3g）等网络状态的信息 -- 
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" / 
<!-- 获取wifi网络状态的信息 -- 
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" / 
<!-- 保持CPU 运转，屏幕和键盘灯有可能是关闭的,用于文件上传和下载 -- 
<uses-permission android:name="android.permission.WAKE_LOCK" / 
<!-- 获取sd卡写的权限，用于文件上传和下载 -- 
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" / 
<!-- 允许读取手机状态 用于创建BmobInstallation -- 
<uses-permission android:name="android.permission.READ_PHONE_STATE" / 
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme"  
<activity
android:name="com.example.text.MainActivity"
android:label="@string/app_name"  
<intent-filter 
<action android:name="android.intent.action.MAIN" / 
<category android:name="android.intent.category.LAUNCHER" / 
</intent-filter 
</activity 
</application 
</manifest