来源: 互联网  发布时间: 2014-02-18

两个坐标间画线

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    linearLayout = (LinearLayout) findViewById(R.id.zoomview);
    mapView = (MapView) findViewById(R.id.mapview);
    mapView.setBuiltInZoomControls(true);

    mapOverlays = mapView.getOverlays();        
    projection = mapView.getProjection();
    mapOverlays.add(new MyOverlay());        

}

@Override
protected boolean isRouteDisplayed() {
    return false;
}

class MyOverlay extends Overlay{

    public MyOverlay(){

    }   

    public void draw(Canvas canvas, MapView mapv, boolean shadow){
        super.draw(canvas, mapv, shadow);

        mPaint = new Paint();
        mPaint.setDither(true);
        mPaint.setColor(Color.RED);
        mPaint.setStyle(Paint.Style.FILL_AND_STROKE);
        mPaint.setStrokeJoin(Paint.Join.ROUND);
        mPaint.setStrokeCap(Paint.Cap.ROUND);
        mPaint.setStrokeWidth(2);

        GeoPoint gP1 = new GeoPoint(19240000,-99120000);
        GeoPoint gP2 = new GeoPoint(37423157, -122085008);

        Point p1 = new Point();
        Point p2 = new Point();

        path = new Path();

        projection.toPixels(gP1, p1);
        projection.toPixels(gP2, p2);

        path.moveTo(p2.x, p2.y);
        path.lineTo(p1.x,p1.y);

        canvas.drawPath(path, mPaint);
    }

    

    来源: 互联网  发布时间: 2014-02-18

andriod学习笔记

根据标准tutorial，学习了android的view，里面讲layout和view合并的概念还是有点不清楚。

想起了当年学swing时的layoutManager，特别是哪个relativeLayoutManager着实让我云里雾里的，现在还不是很清楚，看看android怎么处理这个问题。有兴趣的同学留个言，还有stay tuned...

    

    来源: 互联网  发布时间: 2014-02-18

获得手机上绑定的Google账号
1.5和1.6的系统里没有现成的方法，因而需要用到第三方的库

/**
 * use 3rd package to get Google Account
 * 
 * @param activity
 * @param requestCode
 */
private void getGoogleService(Activity activity, int requestCode) {
	try {
		for (Method ele : Class.forName(
			"com.google.android.googlelogin.GoogleLoginServiceHelper")
			.getMethods()) {
			try {
				if (ele.getName().equals("getAccount")) {
					ele.invoke(null, activity, requestCode, true);
				}
			} catch (IllegalArgumentException e) {
				e.printStackTrace();
			} catch (IllegalAccessException e) {
				e.printStackTrace();
			} catch (InvocationTargetException e) {
				e.printStackTrace();
			}
		}
	} catch (ClassNotFoundException e) {
		e.printStackTrace();
	}
}

返回值需要用下面的方法获得

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
	if (requestCode == REQUEST_GOOGLE_ACCOUNT) {
		String key = "accounts";
		String accounts[] = data.getExtras().getStringArray(key);
		if (accounts != null && accounts[0] != null) {
			String account = accounts[0];
		}
	}
}

这个方法需要在AndroidManifest.xml里增加
<uses-permission android:name="com.google.android.googleapps.permission.GOOGLE_AUTH" />

2.0以后的版本，可以通过AccountManager来获得

/**
 * use Account Manager to get Google Account
 * 
 * @param activity
 */
private void getGoogleServiceWithAccountManager(Activity activity) {

	try {
		// declare class AccountManager
		Class MyAccountManager = Class.forName("android.accounts.AccountManager");
			
		// declare method getAccounts of AccountManager
		Method mGetAccounts = MyAccountManager.getDeclaredMethod("getAccounts");

		for (Method ele : MyAccountManager.getMethods()) {
			try {
				if (ele.getName().equals("get")) {
					// call AccountManager.get to create an instance
					Object obj = ele.invoke(null, activity);

					// call AccountManager.getAccount to get Account[]
					Object accounts[] = (Object[]) mGetAccounts.invoke(obj, null);
					if (accounts.length > 0) {
						// get the class member "name" of class Account
						Field f = accounts[0].getClass().getDeclaredField("name");

						// get the value of class member "name"
						this.mAccount = (String) f.get(accounts[0]);
					}
				}
			} catch (IllegalArgumentException e) {
				e.printStackTrace();
			} catch (IllegalAccessException e) {
				e.printStackTrace();
			} catch (InvocationTargetException e) {
				e.printStackTrace();
			} catch (NoSuchFieldException e) {
				e.printStackTrace();
			}
		}
	} catch (SecurityException e) {
		e.printStackTrace();
	} catch (ClassNotFoundException e) {
		e.printStackTrace();
	} catch (NoSuchMethodException e) {
		e.printStackTrace();
	} finally {
		returnGoogleAccount();
	}
}

考虑到程序可能在低版本的机器上运行，所以方法调用都使用了反射

附件为自己写的代码（包含第三方库文件），写得不好，请多包涵