LTView

自定義檢視的步驟

1. 建立一個繼承自UIView的類
2. 重寫新類的初始化方法
3. 把想封裝的檢視新增封裝到 新類裡面(初始化到新類中)
4. 為了方便外部進行賦值取值 把新增的檢視寫成屬性(別忘了釋放記憶體)
5. 測試一下

自定義檢視的好處

提高工作效率 大大提高程式碼的複用性

具體實現

自定義Label-TextField檢視

建立LTView類繼承自LTView

// 將要建立的控制元件用屬性寫在.h檔案中
@property (strong, nonatomic) UILabel *label;
@property (strong, nonatomic) UITextField *textField;

// 在.m檔案中重寫初始化方法 在初始化LTView的同時新增控制元件
 

- (instancetype)initWithFrame:(CGRect)frame{
    self = [super initWithFrame:frame];
    if (self) {
        // 獲取動態高度
        CGFloat height = frame.size.height;
        // 獲取動態寬度
        CGFloat width = frame.size.width;

        // 根據上面的寬度 來新增label
        self.label = [[UILabel alloc] initWithFrame:CGRectMake(0
 
, 0, width / 3, height)];
        self.label.textAlignment = NSTextAlignmentCenter;
        self.label.backgroundColor = [UIColor blueColor];
        // 新增到自己身上
        [self addSubview:self.label];
        // 釋放空間
        [_label release];

// 動態獲取值構建frame可以適應任何尺寸的螢幕,並且當需求改變時,只需更改第一個控制元件,其餘控制元件位置隨之而改

        // 初始化一個TextField
 

        self.textField = [[UITextField alloc] initWithFrame:CGRectMake(width / 3 + 20, 0, width / 3 * 2 - 20, height)];
        // 設定背景色
        self.textField.backgroundColor = [UIColor greenColor];
        // 新增到檢視上
        [self addSubview:self.textField];
        // 釋放空間
        [_textField release];
    }
    return self;
}

建立登陸介面LoginView利用自定義檢視進行構建

// 首先引入標頭檔案LTView.h
// 在標頭檔案中將需要的控制元件寫成屬性
@property (nonatomic, retain) LTView *userNameLTView;
@property (nonatomic, retain) LTView *passWordLTView;
@property (nonatomic, retain) UIButton *loginButton;
@property (nonatomic, retain) UIButton *registButton;
@property (nonatomic, retain) UIButton *findPasswordButton;

// 在.m檔案中實現新增控制元件
- (instancetype)initWithFrame:(CGRect)frame{
    self = [super initWithFrame:frame];
    if (self) {
    // 初始化輸入賬戶名的l - T
        self.userNameLTView = [[LTView alloc] initWithFrame:CGRectMake((kScreenWidth - 300) / 2, 100, 300, 50)];
        self.userNameLTView.backgroundColor = [UIColor redColor];

        [self addSubview:self.userNameLTView];
        [self.userNameLTView release];
     // 初始化輸入密碼的l - T   
        self.passWordLTView = [[LTView alloc] initWithFrame:CGRectMake(self.userNameLTView.frame.origin.x, self.userNameLTView.frame.origin.y + self.userNameLTView.frame.size.height + kRowHeight, self.userNameLTView.frame.size.width, self.userNameLTView.frame.size.height)];
        self.passWordLTView.backgroundColor = [UIColor redColor];
        [self addSubview:self.passWordLTView];
        [self.passWordLTView release];

        // 迴圈button
        for (int i = 0; i < 3 ; i++) {
            UIButton *button = [UIButton buttonWithType:(UIButtonTypeCustom)];
            button.frame = CGRectMake(50 + i * 100,300 , 80, 50);
            button.backgroundColor = [UIColor cyanColor];

            // 新增標籤 方便取出button 與屬性的button相對應
            button.tag = i + 100;
            [self addSubview:button];
        }
        // 屬性與迴圈建立的button進行關聯
        self.loginButton = (UIButton *)[self viewWithTag:100];
        self.findPasswordButton = (UIButton *)[self viewWithTag:101];
        self.registButton = (UIButton *)[self viewWithTag:102];

將屬性與迴圈建立的控制元件一一對應

// 除了利用tag值 還可以取出父檢視上的子檢視陣列,利用下標進行一一對應
NSArray *array = self.subviews;
self.loginButton = array[2];
[self.loginButton setTitle:@"登陸" forState:(UIControlStateNormal)];

在window上初始化並顯示

LoginView *login = [[LoginView alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    [login.loginButton setTitle:@"登陸" forState:(UIControlStateNormal)];
    [login.registButton setTitle:@"註冊" forState:(UIControlStateNormal)];
    [login.findPasswordButton setTitle:@"找回密碼" forState:(UIControlStateNormal)];
    [login.loginButton setTitleColor:[UIColor redColor] forState:(UIControlStateNormal)];
    [login.registButton setTitleColor:[UIColor redColor] forState:(UIControlStateNormal)];
    [login.findPasswordButton setTitleColor:[UIColor redColor] forState:(UIControlStateNormal)];
    [self.window addSubview:login];
    [login release];

重寫controller的loadView⽅法

建立⾃定義檢視物件，並指定為controller的view

 LoginView *logview = [[LoginView alloc] initWithFrame:[UIScreen mainScreen].bounds];
    logview.tag = 1000;
    // 幫系統給self.view賦值
    self.view = logview;
    [logview release];