android 开发技巧--1

一：
获取程序的版本号，用于提示用户更新
public static int getApplicationVersionCode(Context context) {
        int result = -1;      
        try {          
            PackageManager manager = context.getPackageManager();
            PackageInfo info = manager.getPackageInfo(context.getPackageName(), 0)          
            result = info.versionCode;         
        } catch (NameNotFoundException e) {
            Log.w("ApplicationUtils", "Unable to get application version: " + e.getMessage());
            result = -1;
        }   
        return result;
    }
二：
检测SD卡状态
public static boolean checkCardState(Context context, boolean showMessage) {
        // Check to see if we have an SDCard
        String status = Environment.getExternalStorageState();
        if (!status.equals(Environment.MEDIA_MOUNTED)) {         
            int messageId;
            // Check to see if the SDCard is busy, same as the music app
            if (status.equals(Environment.MEDIA_SHARED)) {
                messageId = R.string.Commons_SDCardErrorSDUnavailable;
            } else {
                messageId = R.string.Commons_SDCardErrorNoSDMsg;
            }          
            if (showMessage) {
                ApplicationUtils.showErrorDialog(context, R.string.Commons_SDCardErrorTitle, messageId);
            }          
            return false;
        }       
        return true;
    }
三：