【移動(dòng)應(yīng)用開(kāi)發(fā)技術(shù)】Android如何實(shí)現(xiàn)相冊(cè)中圖片上傳或下載

這篇文章給大家分享的是有關(guān)Android如何實(shí)現(xiàn)相冊(cè)中圖片上傳或下載的內(nèi)容。在下覺(jué)得挺實(shí)用的，因此分享給大家做個(gè)參考，一起跟隨在下過(guò)來(lái)看看吧。具體內(nèi)容如下目標(biāo)效果：打開(kāi)相冊(cè)選擇一張圖片，會(huì)顯示到上方的ImageView中并存儲(chǔ)到Bmob中，存儲(chǔ)后進(jìn)入Bmob后臺(tái)，復(fù)制剛才添加的數(shù)據(jù)的objectId，粘貼到代碼指定出，然后運(yùn)行，點(diǎn)擊下載會(huì)在下方的ImageView顯示剛才上傳的圖片，這里的下載是指定objectId，可以進(jìn)行動(dòng)態(tài)獲取objectId進(jìn)行下載。1.activity_main.xml頁(yè)面設(shè)置布局。activity_main.xml頁(yè)面：<RelativeLayout

xmlns:android="/apk/res/android"

xmlns:tools="/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="打開(kāi)相冊(cè)"

/>

<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="下載圖片"

/>

<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>2.MainActivity.java頁(yè)面定義上傳與下載方法。MainActivity.java頁(yè)面：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

.Uri;

import

android.os.Bundle;

import

android.os.Environment;

import

vider.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;//

打開(kāi)相冊(cè)

private

static

final

int

RESIZE_CODE

=

2;//

調(diào)整大小

private

static

final

String

IMAGE_NAME

=

"

";//

圖片字符串

@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();

//

綁定點(diǎn)擊事件

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);

}

//

綁定點(diǎn)擊事件

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/*");//圖片

startActivityForResult(galleryIntent,

IMAGE_CODE);

//跳轉(zhuǎn)，傳遞打開(kāi)相冊(cè)請(qǐng)求碼

break;

case

R.id.btnDownloadImage:

BmobQuery<Person>

query=new

BmobQuery<Person>();

query.getObject(this,"ef292ff6ef",new

GetListener<Person>()

{

//第二個(gè)參數(shù)為想要下載的BmobFile數(shù)據(jù)的objectId

@Override

public

void

onSuccess(Person

person)

{

Toast.makeText(MainActivity.this,"獲取成功",Toast.LENGTH_SHORT).show();

//下載圖片

downloadImage(person);

}

@Override

public

void

onFailure(int

arg0,

String

arg1)

{

Toast.makeText(MainActivity.this,"獲取失敗",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);

//

將獲取到的uri轉(zhuǎn)換為String型

String[]

images

=

{

MediaStore.Images.Media.DATA

};//

將圖片URI轉(zhuǎn)換成存儲(chǔ)路徑

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);

}

//

判斷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;

}

}

//

重塑圖片大小

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);//

跳轉(zhuǎn)，傳遞調(diào)整大小請(qǐng)求碼

}

//

獲取路徑

private

Uri

getImageUri()

{

return

Uri.fromFile(new

File(Environment.getExternalStorageDirectory(),

IMAGE_NAME));

}

//

顯示圖片

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);

}

}

//

圖片上傳

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,"圖片上傳成功",Toast.LENGTH_SHORT).show();

}

@Override

public

void

onFailure(int

arg0,

String

arg1)

{

Toast.makeText(MainActivity.this,"圖片上傳失敗",Toast.LENGTH_SHORT).show();

}

});

}

//下載圖片

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));

//根據(jù)地址解碼并顯示圖片

}

@Override

public

void

onFailure(int

arg0,

String

arg1)

{

Toast.makeText(MainActivity.this,"下載失敗",Toast.LENGTH_SHORT).show();

}

});

}

}3.Person.java頁(yè)面為實(shí)體類(lèi)，運(yùn)行自動(dòng)生成一個(gè)Person表，這個(gè)表只有一個(gè)字段存儲(chǔ)圖片。Person.java頁(yè)面：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;

}

}4.因?yàn)槭褂昧薆mob，所以需要添加權(quán)限。AndroidManifest.xml頁(yè)面：<?xml

version="1.0"

encoding="utf-8"?>

<manifest

xmlns:android="/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"/>

<!--

允許聯(lián)網(wǎng)

-->

<uses-permission

android:name="android.permission.INTERNET"

/>

<!--

獲取GSM（2g）、WCDMA（聯(lián)通3g）等網(wǎng)絡(luò)狀態(tài)的信息

-->

<uses-permission

android:name="android.permission.ACCESS_NETWORK_STATE"

/>

<!--

獲取wifi網(wǎng)絡(luò)狀態(tài)的信息

-->

<uses-permission

android:name="android.permission.ACCESS_WIFI_STATE"

/>

<!--

保持CPU

運(yùn)轉(zhuǎn)，屏幕和鍵盤(pán)燈有可能是關(guān)閉的,用于文件上傳和下載

-->

<uses-permission

android:name="android.permission.WAKE_LOCK"

/>