前面寫了UIWindow、UIViewController,那些都是一些框架,框架需要填充上具體的view才能組成我們的應用,移動應用開發中UI占了很大一部分,最基礎的UI實現是使用系統提供的各種控件,其他的就是自定義實現了,作者目前是入門狀態,只能寫寫基礎控件了。
iOS中提供了UIButton、UILable、UITextField、UIImageView等基礎UI控件,繼承於UIView。這里先拿UIButton練練手,為什么拿UIButton呢,因為UIbutton繼承自UIControl,UIControl派生自UIView類,每個控件都有很多視圖的特性,包括附着於其他視圖的能力,所有控件都擁有一套共同的屬性和方法,包含顯示內容,點擊事件等等,UIControl的子類都有事件處理能力。
圖、UIControl

UIButton的定義:
UIButton可使用 initWithFrame、buttonWithType兩種方式創建:
1)initWithFrame
UIButton *btn=[[UIButton alloc]initWithFrame:CGRectMake(60, 60, 200, 60)];
btn.backgroundColor=[UIColor greenColor];
[btn setTitle:@"btn1" forState:UIControlStateNormal];
[self.view addSubview:btn];
2)buttonWithType
UIButton *btn2=[UIButton buttonWithType:UIButtonTypeRoundedRect];
CGRect rect=CGRectMake(60, 160, 200, 60);
btn2.frame=rect;
btn2.tag=1001;
btn2.backgroundColor=[UIColor colorWithRed:30/255.0 green:200/255.0 blue:125/255.0 alpha:1.0];
[btn2 setTitle:@"btn2" forState:UIControlStateNormal];
[btn2 addTarget:self action:@selector(btn2Pressed) forControlEvents:UIControlEventTouchDown];
[self.view addSubview:btn2];
btn2Pressed方法:
-(void)btn2Pressed{
NSLog(@"button pressed");
}
UIButtonType:
typedef enum {
UIButtonTypeCustom = 0, // no button type 自定義,無風格
UIButtonTypeRoundedRect, // rounded rect, flat white button, like in address card 白色圓角矩形,類似偏好設置表格單元或者地址簿卡片
UIButtonTypeDetailDisclosure,//藍色的披露按鈕,可放在任何文字旁
UIButtonTypeInfoLight,//微件(widget)使用的小圓圈信息按鈕,可以放在任何文字旁
UIButtonTypeInfoDark,//白色背景下使用的深色圓圈信息按鈕
UIButtonTypeContactAdd,//藍色加號(+)按鈕,可以放在任何文字旁
} UIButtonType;
UIButton常用屬性:
//設置對應狀態的標題內容default is nil. title is assumed to be single line
- (void)setTitle:(NSString *)title forState:(UIControlState)state;
//設置對應狀態的標題顏色
- (void)setTitleColor:(UIColor *)color forState:(UIControlState)state;
//設置對應狀態的標題陰影顏色
- (void)setTitleShadowColor:(UIColor *)color forState:(UIControlState)state;
//設置對應狀態的按鈕的圖片
- (void)setImage:(UIImage *)image forState:(UIControlState)state;
//設置對應狀態的按鈕背景圖片
- (void)setBackgroundImage:(UIImage *)image forState:(UIControlState)state;
UIButton的UIControlState :
typedef NS_OPTIONS(NSUInteger, UIControlState) {
UIControlStateNormal = 0,
UIControlStateHighlighted = 1 << 0, // used when UIControl isHighlighted is set
UIControlStateDisabled = 1 << 1,
UIControlStateSelected = 1 << 2, // flag usable by app (see below)
UIControlStateApplication = 0x00FF0000, // additional flags available for application use
UIControlStateReserved = 0xFF000000 // flags reserved for internal framework use
};
更多屬性可參考官方文檔。
UIButton添加事件:
[btn addTarget:<#(id)#> action:<#(SEL)#> forControlEvents:<#(UIControlEvents)#>]
這些事件都是基於觸摸、基於值、基於編輯。可相應如下事件。
typedef NS_OPTIONS(NSUInteger, UIControlEvents) {
UIControlEventTouchDown = 1 << 0, // on all touch downs
UIControlEventTouchDownRepeat = 1 << 1, // on multiple touchdowns (tap count > 1)
UIControlEventTouchDragInside = 1 << 2,
UIControlEventTouchDragOutside = 1 << 3,
UIControlEventTouchDragEnter = 1 << 4,
UIControlEventTouchDragExit = 1 << 5,
UIControlEventTouchUpInside = 1 << 6,
UIControlEventTouchUpOutside = 1 << 7,
UIControlEventTouchCancel = 1 << 8,
UIControlEventValueChanged = 1 << 12, // sliders, etc.
UIControlEventEditingDidBegin = 1 << 16, // UITextField
UIControlEventEditingChanged = 1 << 17,
UIControlEventEditingDidEnd = 1 << 18,
UIControlEventEditingDidEndOnExit = 1 << 19, // 'return key' ending editing
UIControlEventAllTouchEvents = 0x00000FFF, // for touch events
UIControlEventAllEditingEvents = 0x000F0000, // for UITextField
UIControlEventApplicationReserved = 0x0F000000, // range available for application use
UIControlEventSystemReserved = 0xF0000000, // range reserved for internal framework use
UIControlEventAllEvents = 0xFFFFFFFF
};
參考:
http://developer.apple.com/library/ios/#documentation/UIKit/Reference/UIButton_Class/UIButton/UIButton.html
http://developer.apple.com/library/ios/#documentation/uikit/reference/UIKit_Framework/Introduction/Introduction.html#//apple_ref/doc/uid/TP40006955-CH1-SW1

一、UIKit結構圖
