Activity快速转换为Diglog

<activity
    android:name=".activity.LoginActivity"
    android:configChanges="keyboard|keyboardHidden|screenLayout|screenSize|orientation"
    android:theme="@style/dialog_style" />

<style name="dialog_style">
    <item name="android:windowIsFloating">true</item>  <!--是否悬浮在activity上-->
    <item name="android:windowNoTitle">true</item> <!--透明是否-->
    <item name="windowActionBar">false</item>
    <item name="android:windowFrame">@null</item>
    <item name="windowNoTitle">true</item>
    <item name="android:windowBackground">@android:color/transparent</item>
    <item name="android:backgroundDimEnabled">true</item>
    <item name="android:windowFullscreen">true</item>
    <item name="android:adjustViewBounds">true</item>
    <item name="android:backgroundDimAmount">0.4</item><!--透明度 0.0f到1.0f之间。1.0完全不透明，0.0f完全透明-->
    <item name="android:windowCloseOnTouchOutside">false</item><!--禁用点击空白处自动关闭-->
</style>

/**
 * 判断qq是否可用
 *
 * @param context
 * @return
 */
public static boolean isQQClientAvailable(Context context) {
    try {
        final PackageManager packageManager = context.getPackageManager();
        List<PackageInfo> pinfo = packageManager.getInstalledPackages(0);
        if (pinfo != null) {
            for (int i = 0; i < pinfo.size(); i++) {
                String pn = pinfo.get(i).packageName;
                if (pn.equals("com.tencent.mobileqq")) {
                    return true;
                }
            }
        }
    }catch (Exception e){
        return false;
    }
    return false;
}
/**
 * 判断支付宝是否可用
 * @param context
 * @return
 */
public static boolean checkAliPayInstalled(Context context) {
    Uri uri = Uri.parse("alipays://platformapi/startApp");
    Intent intent = new Intent(Intent.ACTION_VIEW, uri);
    ComponentName componentName = intent.resolveActivity(context.getPackageManager());
    return componentName != null;
}

private boolean isAvilible( Context context, String packageName )
{
    final PackageManager packageManager = context.getPackageManager();
    // 获取所有已安装程序的包信息
    List<PackageInfo> pinfo = packageManager.getInstalledPackages(0);
    for ( int i = 0; i < pinfo.size(); i++ )
    {
        if(pinfo.get(i).packageName.equalsIgnoreCase(packageName))
            return true;
    }
    return false;
}

/**
 * 程序是否在前台运行 
 *
 * @return
 */
public boolean isAppOnForeground() {
    ActivityManager activityManager = (ActivityManager) getApplicationContext().getSystemService(Context.ACTIVITY_SERVICE);
    String packageName = getApplicationContext().getPackageName();
    List<RunningAppProcessInfo> appProcesses = activityManager
            .getRunningAppProcesses();
    if (appProcesses == null)
        return false;
    for (RunningAppProcessInfo appProcess : appProcesses) {
        // The name of the process that this object is associated with.  
        if (appProcess.processName.equals(packageName)
                && appProcess.importance == RunningAppProcessInfo.IMPORTANCE_FOREGROUND) {
            return true;
        }
    }
    return false;
}

 public static boolean isNullOrEmpty(String str) {
        if (str == null) return true;
        if (str.equals("null")) return true;
        if (str.equals("[null]")) return true;
        if (str.isEmpty()) return true;
        if (str.equals("")) return true;
        if (str.equals("(null)")) return true;
        return false;
    } 

/**
 * 是否为当前界面
 * @param cls 当前界面
 * @return true是当前界面
 */
private boolean isRunningActivity(Class<?> cls)
{
   ActivityManager activityManager = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE);
   String runningActivity = activityManager.getRunningTasks(1).get(0).topActivity.getClassName();
   return cls.getName().equals(runningActivity);
}