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，繼承于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，包括附著于其他視圖的能力，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 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; ~~~ 更多屬性可參考官方文檔。 **UIButton添加事件：** UIButton使用如下方法添加事件。 ~~~ [btn addTarget:<#(id)#> action:<#(SEL)#> forControlEvents:<#(UIControlEvents)#>] ~~~ 這些事件都是基于觸摸、基于值、基于編輯。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 }; ~~~