登陸圓形頭像之網絡加載與緩存到本地

Android開發中經常有用戶頭像顯示，彷佛大多數都是圓形顯示，若是每次加載網絡頭像，會頻繁的請求網絡，因此本文主要說的是登陸時的頭像網絡加載和緩存到本地，以便於下次加載時直接從本地獲取便可。

效果圖：

      

自定義控件實現圓形頭像顯示請看， Android自定義ImageView實現圖片圓形 ，橢圓和矩形圓角顯示 這篇博客便可。

 

/*****
 * 
 * 圓形頭像+HTTP網絡加載頭像並緩存到本地
 * 
 * 
 * @author zq
 * 
 */
public class MainActivity extends Activity implements OnClickListener {

	private ImageView mImageView, mImageView2;
	String url = " http://avatar.csdn.net/8/6/0/1_dickyqie.jpg";
	private String mFileName;
	private String mSaveMessage;
	Util util = new Util();
	private Bitmap mBitmap;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		initView();
	}

	private void initView() {
		// TODO Auto-generated method stub
		mImageView = (ImageView) findViewById(R.id.personal_image);
		mImageView2 = (ImageView) findViewById(R.id.personal_image2);
		findViewById(R.id.button1).setOnClickListener(this);
		findViewById(R.id.button2).setOnClickListener(this);

	}

	@Override
	public void onClick(View v) {
		// TODO Auto-generated method stub
		switch (v.getId()) {
		case R.id.button1:
			new Thread(connectNet).start();
			break;
		case R.id.button2:
			Bitmap ben = BitmapFactory.decodeFile(Util.ALBUM_PATH + mFileName);
			mImageView2.setImageBitmap(ben);
			break;
		default:
			break;
		}
	}

	private Runnable saveFileRunnable = new Runnable() {
		@Override
		public void run() {
			try {
				util.saveFile(mBitmap, mFileName);
				mSaveMessage = "圖片保存成功！";
			} catch (IOException e) {
				mSaveMessage = "圖片保存失敗！";
				e.printStackTrace();
			}
			messageHandler.sendMessage(messageHandler.obtainMessage());
		}

	};

	private Handler messageHandler = new Handler() {
		@Override
		public void handleMessage(Message msg) {
			Toast.makeText(MainActivity.this, mSaveMessage, 1).show();

		}
	};

	/*
	 * 鏈接網絡 因爲在4.0中不容許在主線程中訪問網絡，因此須要在子線程中訪問
	 */
	private Runnable connectNet = new Runnable() {
		@Override
		public void run() {
			try {
				String filePath = url;
				mFileName = "test.jpg";

				// 如下是取得圖片的兩種方法
				// 方法1：取得的是byte數組, 從byte數組生成bitmap
				byte[] data = util.getImage(filePath);
				if (data != null) {
					mBitmap = BitmapFactory.decodeByteArray(data, 0,
							data.length);
				} else {
					Toast.makeText(MainActivity.this, "Image error!", 1).show();
				}

				// ******** 方法2：取得的是InputStream，直接從InputStream生成bitmap
				// mBitmap =
				// BitmapFactory.decodeStream(util.getImageStream(filePath));
				// 發送消息，通知handler在主線程中更新UI
				connectHanlder.sendEmptyMessage(0);
			} catch (Exception e) {
				Toast.makeText(MainActivity.this, "沒法連接網絡！", 1).show();
				e.printStackTrace();
			}

		}

	};

	private Handler connectHanlder = new Handler() {
		@Override
		public void handleMessage(Message msg) {
			// 更新UI，顯示圖片
			if (mBitmap != null) {
				mImageView.setImageBitmap(mBitmap);// display image
				new Thread(saveFileRunnable).start();
			}
		}
	};

}

不要忘記在AndroidManifest.xml加權限哦！

<uses-permission android:name="android.permission.INTERNET"></uses-permission>
	<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
	<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>
	<uses-permission android:name="android.permission.READ_PHONE_STATE"></uses-permission>
	<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"></uses-permission>
	<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"></uses-permission>
	<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"></uses-permission>

 

因爲代碼太多，完整代碼未給出，源碼直接下載便可

 

源碼點擊下載：https://github.com/DickyQie/android-cache