判断是否安装了Google地图

判断是否安装了Google地图，没有弹出Dialog提示安装：

/**
	 * For Google Maps Check
	 * 
	 * @return
	 */
	private boolean isGoogleMapsInstalled() {
		try {
			ApplicationInfo info = getPackageManager().getApplicationInfo(
					"com.google.android.apps.maps", 0);
			return true;
		} catch (PackageManager.NameNotFoundException e) {
			return false;
		}
	}

	private OnClickListener getGoogleMapsListener() {
		return new OnClickListener() {
			@Override
			public void onClick(DialogInterface dialog, int which) {
				Intent intent = new Intent(
						Intent.ACTION_VIEW,
						Uri.parse("market://details?id=com.google.android.apps.maps"));
				startActivity(intent);

				// Finish the activity so they can't circumvent the check
				finish();
			}
		};
	}

	public void checkGoogleMapInstalled() {
		if (!this.isGoogleMapsInstalled()) {
			AlertDialog.Builder builder = new AlertDialog.Builder(this);
			builder.setMessage("Install Google Map ?");
			builder.setCancelable(false);
			builder.setPositiveButton("Install", getGoogleMapsListener());
			AlertDialog dialog = builder.create();
			dialog.show();
		}
	}

判断是否安装了地图（无论什么地图）

类似这样子：

try {
						Uri mUri = Uri
								.parse("geo:31.249351,121.45905?q=上海交通大学&z=18");
						intent = new Intent(Intent.ACTION_VIEW, mUri);
						startActivity(intent);
					} catch (Exception e) {
						// TODO: handle exception
						showToast("您未安装地图，不能查看！");
					}

打开某一个已知程序

//打开日历
try{
				intent=new Intent();
				intent.setComponent(new ComponentName("com.android.calendar", "com.android.calendar.LaunchActivity"));  
				startActivity(intent);
			}catch (ActivityNotFoundException e) {
				// TODO: handle exception
				Log.i("tag", "Sorry,we have not found the App.");
			}
//打开另一个已知包名和启动类的App
try{
				intent=new Intent();  
	            intent.setComponent(new ComponentName("com.ata.app","com.ata.app.LogoActivity"));
	            startActivity(intent); 
			}catch (ActivityNotFoundException e) {
				// TODO: handle exception
				Log.i("tag", "Sorry,we have not found the App.");
			}

判断服务是否运行.

/**
     * 判断服务是否运行.
     * @param context
     * @param className 判断的服务名字
     * @return true 在运行 false 不在运行
     */
	public static boolean isServiceRunning(Context mContext, String className) {
		ActivityManager activityManager = (ActivityManager) mContext.getSystemService(Context.ACTIVITY_SERVICE);
		List<ActivityManager.RunningServiceInfo> serviceList = activityManager.getRunningServices(Integer.MAX_VALUE);
				
		for(ActivityManager.RunningServiceInfo info:serviceList){
			if(info.service.getClassName().equals(className)){
				return true;
			}
		}
		return false;
	}

让你的Android应用与外部元素互动起来