UI_02 基礎視圖、程序啓動流程

⼀、UITextField

UITextField（輸⼊框）：是控制⽂本輸⼊和顯⽰的控件

UITextField核⼼功能主要包含3個⽅⾯： ⽂本顯⽰ 輸⼊控制 外觀配置

一、⽂本顯⽰

//    textField.text = @"你好";

//    textField.textAlignment = NSTextAlignmentCenter;

    textField.textColor = [UIColor blueColor];

    textField.placeholder = @"請輸入我愛編程";

    textField.font = [UIFont fontWithName:@"" size:20];

二、輸⼊控制

    textField.enabled = YES;
    textField.clearsOnBeginEditing = NO;
    textField.secureTextEntry = YES;
    textField.keyboardType = UIKeyboardTypeDefault;

    textField.returnKeyType = UIReturnKeyDefault;

//自定義鍵盤視圖
    UIView * inputView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 0, 180)];
    inputView.backgroundColor = [UIColor blueColor];
    textField.inputView = inputView;
    [inputView release];
//自定義鍵盤輔助視圖
    UIView * inputAccessaryView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 0, 60)];
    inputAccessaryView.backgroundColor = [UIColor yellowColor];
    textField.inputAccessoryView = inputAccessaryView;

    [inputAccessaryView release];

三、外觀控制

    textField.borderStyle = UITextBorderStyleRoundedRect;
    textField.clearButtonMode = UITextFieldViewModeWhileEditing;

    //設置文本框左視圖

    UIButton * button = [UIButton buttonWithType:UIButtonTypeCustom];

    button.frame = CGRectMake(0, 0, 40, 40);

    [button setBackgroundImage:[UIImage imageNamed:@"face_monkey_2_24px_541648_easyicon.net.png"] forState:UIControlStateNormal];

    textField.leftView = button;

    textField.leftViewMode = UITextFieldViewModeAlways;

---

2、UIButton

一、UIButton的狀態

normal（普通狀態）

默認狀況

對應的枚舉常量：UIControlStateNormal

highlighted（高亮狀態）

按鈕被按下去的時候（手指還未鬆開）

對應的枚舉常量：UIControlStateHighlighted

disabled（失效狀態，不可用狀態）

若是enabled屬性爲NO，就是處於disable狀態，表明按鈕不能夠被點擊

對應的枚舉常量：UIControlStateDisabled

UIButton有不少種狀態，它提供了一些便捷屬性，能夠直接獲取當前狀態下的文字、文字顏色、圖片等
@property(nonatomic,readonly,retain) NSString *currentTitle;
@property(nonatomic,readonly,retain) UIColor  *currentTitleColor;
@property(nonatomic,readonly,retain) UIImage  *currentImage;

@property(nonatomic,readonly,retain) UIImage  *currentBackgroundImage;

    UIButton * button = [UIButton buttonWithType:UIButtonTypeSystem];
//    button.backgroundColor = [UIColor blackColor];
    button.frame = CGRectMake(30, 100, 50, 50);
//    button.layer.cornerRadius = 20;
    //設置前景圖片
    [button setImage:[UIImage imageNamed:@""] forState:UIControlStateNormal];
    //設置背景圖片
    //設置普通狀態下的背景圖片
    [button setBackgroundImage:[UIImage imageNamed:@"normal.png"] forState:UIControlStateNormal];
    //設置高亮狀態下的背景圖片
    [button setBackgroundImage:[UIImage imageNamed:@"hilighted.png"] forState:UIControlStateHighlighted];
    //添加事件
    [button addTarget:self action:@selector(clickButton:) forControlEvents:UIControlEventTouchUpInside];
    //設置按鈕title
    [button setTitle:@"綠鳥" forState:UIControlStateNormal];
    [button setTitle:@"藍鳥" forState:UIControlStateHighlighted];

    [button setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];

- (void)clickButton:(UIButton *)button
{
    self.window.backgroundColor = [UIColor colorWithRed:random()%100/100.0 green:random()%100/100.0 blue:random()%100/100.0 alpha:1];
    button.backgroundColor = [UIColor whiteColor];

}

---

3、AppDelegate

＊＊＊＊鍵盤收回＊＊＊＊

一、將AppDelegate做爲UITextField的delegate

@interface AppDelegate : UIResponder <UIApplicationDelegate, UITextFieldDelegate>

二、AppDelegate.m⽂件實現textFieldShouldReturn:⽅法

- (void)textFieldDidBeginEditing:(UITextField *)textField

{
    [textField becomeFirstResponder];
    NSLog(@"%s", __FUNCTION__);

}// became first responder

- (BOOL)textFieldShouldReturn:(UITextField *)textField
{

    NSLog(@"%s", __FUNCTION__);     // 輸出方法名

    [textField resignFirstResponder];
    return YES;

}// called when 'return' key pressed. return NO to ignore.

三、添加代理

    textField.delegate = self;

＊＊＊＊觸摸鍵盤外空白區域隱藏鍵盤＊＊＊＊

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event

{
    UITouch *touch = [touches anyObject];
   
    if (![touch.view isKindOfClass: [UITextField class]] || ![touch.view isKindOfClass: [UITextView class]]) {
       

        [self.window endEditing:YES];       

    }

    [super touchesBegan:touches withEvent:event];

}

---

4、iOS程序啓動流程

一、程序入口

int main(int argc, char * argv[]) {

    @autoreleasepool {

        return UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class]));
    }

}

UIApplicationMain剖析:

    argc: argv[].count

    argv[]: 存放的是全部的參數

    principalClassName:若是是nil，UIApplicationMain()函數會給系統建立一個UIApplication這個類的一個對象，並且是惟一的，叫作應用程序對象

    delegateClassName:UIApplicationMain()使用給定類建立代理並給應用程序設置代理

    UIApplicationMain()這個函數，開啓事件循環

二、UIApplicationDelegate

UIApplicationDelegate是⼀個OC的協議。⾥⾯聲明瞭⼀堆⽅法，這些⽅ 法都與應⽤程序運⾏狀態有關，它們由應⽤程序代理實現。UIApplication 對象負責調⽤。

iOS生命週期：

UIApplicationDelegate

程序啓動：

application:didFinishLaunchingWithOptions:

applicationDidBecomeActive:

掛起：

applicationWillResignActive:     （tag:按兩下Home鍵只發送此消息）

applicationDidEnterBackground:

恢復：

applicationWillEnterForeground:

applicationDidBecomeActive:     （tag:今後狀態返回程序只發送此消息）

結束：

applicationWillResignActive:   

applicationDidEnterBackground:

AppDelegate applicationWillTerminate:

輸出函數名：

    NSLog(@"%s", __FUNCTION__);