To check the object in the code above, that should check whether the object is nil.
Please note that, that is a pointer. If it has not initialized yet, it will be nil, not NSNull null.
null is a value for nothings, all pointer won't be null, unless you assign that is null object to there.
I found a good website for Bootstrap, BootstrapZero.. There are some starter kit to build a bootstrap website, such as a basic image slider website, admin console and silde bar website. Moreover, there are a number good free bootstap templates, such as a google plus like and facebook like templates. All of them are free of charge under a MIT License. I found there are enough resources to build a website. I do not need to buy other stuff online.
Stackpanel is a useful layout control in WPF. If you have a set of elements need to sit side by side each other, this is your best option. For example, in my advgen contact manager, in the right hand side, there is a set of buttons. Thus, I placed a stack panel. However, by the default, the controls inside the panel will flow in vertical direct, you need to set Orientation="Horizontal"
<StackPanel FlowDirection="LeftToRight" Orientation="Horizontal">
I have some styling in my WPF opensource project, AdvGen Contact Manager. That is similar with css, just state the class name like :
if you only have an ok button for alert view, that is easy.
However, if you have more than an "OK" button, you need to implement your controller as UIAlertViewDelegate
@interface TipRecordListViewController : UITableViewController < uialertviewdelegate >
You need to implement clickedButtonAtIndex
The buttonIndex will tell you which button is clicked