IOS study note 4

1. FAQs

A. Why can't I click the created uibutton?

The possible cause is that the uiview is no longer small in initwithframe and exceeds the uiwindow area.

B. presentmodalviewcontroller animation effect

Modaltransitionstyle = uimodaltransitionstylefliphorizontal;

[Self dismissmodalviewcontrolleranimated: Yes];

 

C. Why is the key value of nsdictionary always null?

It is best not to assign values directly when initializing a number, like this [nsnumber numberwithint: 0]

D. Why does loadview keep running (loop)

As follows:

 
-(Void) Loadview
{
Helloview * helloview = [[helloview alloc] init] autorelease];

[Helloview setneedsdisplay];
[Self. View addsubview: helloview];

}
 

Because [Super loadview] is missing;

Which of the following statements is true?

 
-(Void) Loadview
{
[Super loadview];
Helloview * helloview = [[helloview alloc] init] autorelease];

[Helloview setneedsdisplay];
[Self. View addsubview: helloview];

}