andriod 中下载图片到sdcard中例子

Android实现下载图片并保存到SD卡中收藏

1.java代码，下载图片的主程序

先实现显示图片，然后点击下载图片按钮，执行下载功能。

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01.package com.min.android_test_2_3_3;
02.
03.import java.io.BufferedOutputStream;
04.import java.io.ByteArrayOutputStream;
05.import java.io.File;
06.import java.io.FileOutputStream;
07.import java.io.IOException;
08.import java.io.InputStream;
09.import java.net.HttpURLConnection;
10.import java.net.URL;
11.
12.import android.app.Activity;
13.import android.app.ProgressDialog;
14.import android.graphics.Bitmap;
15.import android.graphics.BitmapFactory;
16.import android.os.Bundle;
17.import android.os.Environment;
18.import android.os.Handler;
19.import android.os.Message;
20.import android.util.Log;
21.import android.view.View;
22.import android.widget.Button;
23.import android.widget.ImageView;
24.import android.widget.Toast;
25.public class AndroidTest2_3_3 extends Activity {
26. private final static String TAG = "AndroidTest2_3_3";
27. private final static String ALBUM_PATH
28. = Environment.getExternalStorageDirectory() + "/download_test/";
29. private ImageView imageView;
30. private Button btnSave;
31. private ProgressDialog myDialog = null;
32. private Bitmap bitmap;
33. private String fileName;
34. private String message;
35.
36.
37. @Override
38. protected void onCreate(Bundle savedInstanceState) {
39. super.onCreate(savedInstanceState);
40. setContentView(R.layout.main);
41.
42. imageView = (ImageView)findViewById(R.id.imgSource);
43. btnSave = (Button)findViewById(R.id.btnSave);
44.
45. String filePath = "http://hi.csdn.net/attachment/201105/21/134671_13059532779c5u.jpg";
46. fileName = "test.jpg";
47.
48. try {
49. byte[] data = getImage(filePath);
50. if(data!=null){
51. bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);// bitmap
52. imageView.setImageBitmap(bitmap);// display image
53. }else{
54. Toast.makeText(AndroidTest2_3_3.this, "Image error!", 1).show();
55. }
56. } catch (Exception e) {
57. Toast.makeText(AndroidTest2_3_3.this,"Newwork error!", 1).show();
58. e.printStackTrace();
59. }
60.
61.
62. // 下载图片
63. btnSave.setOnClickListener(new Button.OnClickListener(){
64. public void onClick(View v) {
65. myDialog = ProgressDialog.show(AndroidTest2_3_3.this, "保存图片", "图片正在保存中，请稍等...", true);
66. new Thread(saveFileRunnable).start();
67. }
68. });
69.
70. }
71.
72. /**
73. * Get image from newwork
74. * @param path The path of image
75. * @return
76. * @throws Exception
77. */
78. public static byte[] getImage(String path) throws Exception{
79. URL url = new URL(path);
80. HttpURLConnection conn = (HttpURLConnection) url.openConnection();
81. conn.setConnectTimeout(5 * 1000);
82. conn.setRequestMethod("GET");
83. InputStream inStream = conn.getInputStream();
84. if(conn.getResponseCode()==200){
85. return readStream(inStream);
86. }
87. return null;
88. }
89.
90. /**
91. * Get data from stream
92. * @param inStream
93. * @return
94. * @throws Exception
95. */
96. public static byte[] readStream(InputStream inStream) throws Exception{
97. ByteArrayOutputStream outStream = new ByteArrayOutputStream();
98. byte[] buffer = new byte[1024];
99. int len = 0;
100. while( (len=inStream.read(buffer)) != -1){
101. outStream.write(buffer, 0, len);
102. }
103. outStream.close();
104. inStream.close();
105. return outStream.toByteArray();
106. }
107.
108. /**
109. * 保存文件
110. * @param bm
111. * @param fileName
112. * @throws IOException
113. */
114. public void saveFile(Bitmap bm, String fileName) throws IOException {
115. File dirFile = new File(ALBUM_PATH);
116. if(!dirFile.exists()){
117. dirFile.mkdir();
118. }
119. File myCaptureFile = new File(ALBUM_PATH + fileName);
120. BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(myCaptureFile));
121. bm.compress(Bitmap.CompressFormat.JPEG, 80, bos);
122. bos.flush();
123. bos.close();
124. }
125.
126. private Runnable saveFileRunnable = new Runnable(){
127. @Override
128. public void run() {
129. try {
130. saveFile(bitmap, fileName);
131. message = "图片保存成功！";
132. } catch (IOException e) {
133. message = "图片保存失败！";
134. e.printStackTrace();
135. }
136. messageHandler.sendMessage(messageHandler.obtainMessage());
137. }
138.
139. };
140.
141. private Handler messageHandler = new Handler() {
142. @Override
143. public void handleMessage(Message msg) {
144. myDialog.dismiss();
145. Log.d(TAG, message);
146. Toast.makeText(AndroidTest2_3_3.this, message, Toast.LENGTH_SHORT).show();
147. }
148. };
149.
150.}

下载进度条的可以参考我的另外一个帖子：Android更新下载进度条

2.main.xml文件，只有一个button和一个ImageView

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01.<?xml version="1.0" encoding="utf-8"?>
02.<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
03. android:orientation="vertical"
04. android:layout_width="fill_parent"
05. android:layout_height="fill_parent"
06. >
07. <Button
08. android:id="@+id/btnSave"
09. android:layout_width="wrap_content"
10. android:layout_height="wrap_content"
11. android:text="保存图片"
12. />
13. <ImageView
14. android:id="@+id/imgSource"
15. android:layout_width="wrap_content"
16. android:layout_height="wrap_content"
17. android:adjustViewBounds="true"
18. />
19.</LinearLayout>

3.在mainfest文件中增加互联网权限和写sd卡的权限

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01.<uses-permission android:name="android.permission.INTERNET" />
02.<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
03. <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>

预览图：

本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/ameyume/archive/2011/06/06/6528205.aspx

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