Android中显示网络上的图片

在android中显示网络上的图片，需要先根据url找到图片地址，然后把该图片转化成java的InputStream，然后把该InputStream流转化成BitMap，BitMap可以直接显示在android中的ImageView里。这就是显示网络上图片的思路，实现起来很简单。下面让我们看一下实现起来的过程。

首先在AndroidManifest.xml中给程序加易做图问Internet的权限：

<uses-permissionandroid:name="android.permission.INTERNET" />

然后在布局文件中加入一个ImageView，用来显示网络上的图片：

[html] <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent"
 android:orientation="vertical" >

 <TextView
 android:layout_width="fill_parent"
 android:layout_height="wrap_content"
 android:text="@string/hello" />
 <ImageView
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:id="@+id/imageView" />

</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent"
 android:orientation="vertical" >

</LinearLayout>

在主程序的Activity中写从网络中得到图片，并转化成InputStream，然后再转化成可以显示在ImageView里的Bitmap。

[java] package com.image;

import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.widget.ImageView;

public class NetImageActivity extends Activity {
 /** Called when the activity is first created. */
 String imageUrl = "/2012/0416/20120416110127604.jpg";
 Bitmap bmImg;
 ImageView imView;
 @Override
 public void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.main);
 imView = (ImageView) findViewById(R.id.imageView);
 imView.setImageBitmap(returnBitMap(imageUrl));
 }

 public Bitmap returnBitMap(String url){
 URL myFileUrl = null;
 Bitmap bitmap = null;
 try {
 myFileUrl = new URL(url);
 } catch (MalformedURLException e) {
 e.printStackTrace();
 }
 try {
 HttpURLConnection conn = (HttpURLConnection) myFileUrl
 .openConnection();
 conn.setDoInput(true);
 conn.connect();
 InputStream is = conn.getInputStream();
 bitmap = BitmapFactory.decodeStream(is);
 is.close();
 } catch (IOException e) {
 e.printStackTrace();
 }
 return bitmap;
 }
}

package com.image;

import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.widget.ImageView;

public class NetImageActivity extends Activity {
    /** Called when the activity is first created. */
String imageUrl = "/2012/0416/20120416110127604.jpg";
Bitmap bmImg;
ImageView imView;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        imView = (ImageView) findViewById(R.id.imageView);
        imView.setImageBitmap(returnBitMap(imageUrl));

补充：移动开发 , Android ,