android控件ImageView加载sdcard卡，网络及res中的图片

提前声明

加载网络资源需要网络访问权限：

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

加载sd卡中的资源则需要权限：

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

不然，  不然 ， 代码正确，但一直会抛异常哟  因为没权限呀 没权限

效果图：





一：

先说访问res/drawable/下的图片的访问方法中，因为这种最简单，getResources()是Context的方法。

myPic.setImageDrawable(getResources().getDrawable(R.drawable.ic_launcher));

二：
访问本地SD卡中的图片

String path=Environment.getExternalStorageDirectory().toString()+"/aa.jpg";
Bitmap bitmap = getLoacalBitmap(path); //从本地取图片

三：

访问网络上的图片资源

这种情况下，要注意一下，android不允许在 在跟界面操作所在的线程中加入会导致程序反应迟钝的操作，譬如上网加载网上的数据，这些操作，要实现就一定得放到其他线程中去执行。这里，为了简便起见，咱们就直接用网上的async-http开源框架好了，内部实现原理就是开线程专门加载资源，加载完再反馈界面主线程。

操作起来还算简单，记得下载android-async-http-1.4.6.jar包，我用的1.4.6  后面的版本会出点问题。

String url="http://img.club.pchome.net/upload/club/other/2015/6/24/pics_kdsxxoo_1435102809.jpg";
AsyncHttpClient client=new AsyncHttpClient();

client.get(url, new AsyncHttpResponseHandler(){
@Override
public void onSuccess(int statusCode, Header[] headers, byte[] responseBody) {
if(statusCode==200){
BitmapFactory factory=new BitmapFactory();
Bitmap bitmap=factory.decodeByteArray(responseBody, 0, responseBody.length);
myPic.setImageBitmap(bitmap);
}
}

@Override
public void onFailure(int statusCode, Header[] headers,
byte[] responseBody, Throwable error) {
error.printStackTrace();
}
});

源码：
activity_main.xml

<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="com.liang.test1.MainActivity" >

<ImageView
android:id="@+id/mypic"
android:layout_width="400dp"
android:layout_height="400dp"
android:layout_centerInParent="true"
android:scaleY="3"
android:scaleX="1.5"
android:rotationY="35"
android:src="@drawable/aaa"/>

</RelativeLayout>

MainActivity.java

package com.liang.test1;

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

import org.apache.http.Header;

import com.loopj.android.http.AsyncHttpClient;
import com.loopj.android.http.AsyncHttpResponseHandler;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Window;
import android.view.animation.AlphaAnimation;
import android.view.animation.Animation;
import android.view.animation.RotateAnimation;
import android.widget.ImageView;
import android.widget.Toast;

public class MainActivity extends Activity implements OnClickListener{

private static final String TAG = "MAIN_ACTIVITY";
//	private Button leftBottomBut;
//	private Button rightBottomBut;
//	private Button leftTopBut;
//	private Button rightTopBut;
private ImageView myPic;
private AlphaAnimation myAnimation_Alpha;
private RotateAnimation myAnimation_Rotate;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.getWindow().requestFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.activity_main);
myPic=(ImageView)findViewById(R.id.mypic);
myPic.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
String url="http://img.club.pchome.net/upload/club/other/2015/6/24/pics_kdsxxoo_1435102809.jpg";
AsyncHttpClient client=new AsyncHttpClient();

client.get(url, new AsyncHttpResponseHandler(){
@Override
public void onSuccess(int statusCode, Header[] headers, byte[] responseBody) {
if(statusCode==200){
BitmapFactory factory=new BitmapFactory();
Bitmap bitmap=factory.decodeByteArray(responseBody, 0, responseBody.length);
myPic.setImageBitmap(bitmap);
}
}

@Override
public void onFailure(int statusCode, Header[] headers,
byte[] responseBody, Throwable error) {
error.printStackTrace();
}
});

Toast.makeText(MainActivity.this, "pic was clicked", Toast.LENGTH_SHORT).show();
//				 Bitmap bitmap =getHttpBitmap("http://blog.3gstdy.com/wp-content/themes/twentyten/images/headers/path.jpg");
String path=Environment.getExternalStorageDirectory().toString()+"/aa.jpg";
Bitmap bitmap = getLoacalBitmap(path); //从本地取图片
//				myPic.setImageDrawable(getResources().getDrawable(R.drawable.ic_launcher));

myPic.setImageBitmap(bitmap);
//				AlphaAnimation(float fromAlpha, float toAlpha)
//说明:0.0表示完全透明,1.0表示完全不透明
myAnimation_Rotate=new RotateAnimation(0.0f, +350.0f,Animation.RELATIVE_TO_SELF,0.5f,Animation.RELATIVE_TO_SELF, 0.5f);

myAnimation_Alpha=new AlphaAnimation(0.1f, 1.0f);
myAnimation_Rotate.setDuration(5000);
myPic.setAnimation(myAnimation_Rotate);
myAnimation_Rotate.start();
}
});
//		leftBottomBut=(Button)findViewById(R.id.left_bottom_but);
//		leftBottomBut.setOnClickListener(this);
//		rightBottomBut=(Button)findViewById(R.id.right_bottom_but);
//		rightBottomBut.setOnClickListener(this);
//		leftTopBut=(Button)findViewById(R.id.left_top_but);
//		leftTopBut.setOnClickListener(new View.OnClickListener() {
//
//			@Override
//			public void onClick(View arg0) {
//				// TODO Auto-generated method stub
//				Toast.makeText(MainActivity.this, "left_top_but clicked", Toast.LENGTH_SHORT).show();
//			}
//		});
//		rightTopBut=(Button)findViewById(R.id.right_top_but);
//		rightTopBut.setOnClickListener(this);
}

/**
* 加载本地图片
* http://bbs.3gstdy.com * @param url
* @return
*/
public static Bitmap getLoacalBitmap(String url) {
try {
FileInputStream fis = new FileInputStream(url);
return BitmapFactory.decodeStream(fis);
} catch (FileNotFoundException e) {
e.printStackTrace();
return null;
}
}

public static Bitmap getHttpBitmap(String url) {
URL myFileUrl = null;
Bitmap bitmap = null;
try {
Log.d(TAG, url);
myFileUrl = new URL(url);
} catch (MalformedURLException e) {
e.printStackTrace();
}
try {
HttpURLConnection conn = (HttpURLConnection) myFileUrl.openConnection();
conn.setConnectTimeout(0);
conn.setDoInput(true);
conn.connect();
InputStream is = conn.getInputStream();
bitmap = BitmapFactory.decodeStream(is);
is.close();
} catch (IOException e) {
e.printStackTrace();
}
return bitmap;
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
//		switch(v.getId())
//		{
//		case R.id.left_bottom_but:
//			Toast.makeText(this, "left_bottom_but clicked", Toast.LENGTH_SHORT).show();
//			break;
//		case R.id.right_bottom_but:
//			Toast.makeText(this, "right_bottom_but clicked", Toast.LENGTH_SHORT).show();
//			break;
//		default:
//			break;
//		}
}

public void butclicked(View v)
{
//		switch(v.getId())
//		{
//		case R.id.right_top_but:
//			Toast.makeText(this, "right_top_but clicked", Toast.LENGTH_SHORT).show();
//			break;
//		default:
//			break;
//		}
}
}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.liang.test1"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk
android:minSdkVersion="15"
android:targetSdkVersion="15" />

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

<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name=".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>