6.自定义视图知识总结

自定义视图步骤

1.创建一个继承自UIView类

2.重写新类的初始化方法

3.把想添加的视图封装到新类里(初始化到新类)

4.为了方便外部进行赋值或者取值 把添加的视图写成属性（别忘了释放）

5.测试一下

自定义视图的好处: 提高工作效率 大大提高代码的复用性

1.创建一个继承自UIView类

@interface LTView : UIView

2.把要添加的视图写成属性（别忘了释放）要添加多少视图就写多少个属性

@property (nonatomic,retain)UILabel *label;

@property (nonatomic,retain)UITextField *textField;

添加成属性就要记得释放

– (void)dealloc

{

[_label release];

[_textField release];

[super dealloc];

}

3.重写新类的初始化方法

4.把想添加的视图封装到新类里(初始化到新类)

– (instancetype)initWithFrame:(CGRect)frame

{

self = [super initWithFrame:frame];

if (self) {

获取动态宽度

CGFloat width = frame.size.width;

获取动态高度

CGFloat height = frame.size.height;

根据上面的宽度 在本视图上添加label

self.label = [[UILabel alloc] initWithFrame:CGRectMake(0, 0,(width / 3), height)];

设置label的属性
self.label.backgroundColor = [UIColor yellowColor];

把文本视图添加到本视图上
[self addSubview:self.label];

释放
[_label release];

根据上面的宽度 在本视图上添加textField

self.textField = [[UITextField alloc] initWithFrame:CGRectMake(width / 3 + 20, 0, (width - width / 3 - 20), height)];
设置textField的属性
self.textField.backgroundColor = [UIColor greenColor];

把输入框添加到本视图上
[self addSubview:self.textField];

释放
[_textField release];
}
return self;

}

创建好的自定义视图还可以复用

1.创建一个继承自UIView类和引入自定义视图的头文件

#import “LTView.h”

@interface LoginView : UIView

2.把要添加的视图写成属性

@property(nonatomic,retain)LTView *userNameLTView;

@property(nonatomic,retain)LTView *passwordLTView;

@property(nonatomic,retain)UIButton *loginButton;

@property(nonatomic,retain)UIButton *registerButton;

@property(nonatomic,retain)UIButton *retrieveButton;

– (void)dealloc

{

[_passwordLTView release];

[_userNameLTView release];

[_loginButton release];

[_loginButton release];

[_retrieveButton release];

[super dealloc];

}

宏定义屏幕的高

#define kScreenHeight [UIScreen mainScreen].bounds.size.height

宏定义屏幕的高

#define kScreenWidth [UIScreen mainScreen].bounds.size.width

宏定义 行间距

#define kRowHeight 30

3.重写初始化方法

– (instancetype)initWithFrame:(CGRect)frame

{

self = [super initWithFrame:frame];

if (self) {

创建一个引入的自定义视图
self.userNameLTView = [[LTView alloc] initWithFrame:CGRectMake((kScreenWidth - 300)/2 , 100, 300, 50)];

给引入的自定义视图设置属性
self.userNameLTView.backgroundColor = [UIColor magentaColor];

将引入的自定义视图添加到本自定义视图上
[self addSubview:self.userNameLTView];

释放
[_userNameLTView release];

获取上一个自定义视图的x,y,宽,高.
CGFloat width = self.userNameLTView.frame.size.width;
CGFloat height = self.userNameLTView.frame.size.height;
CGFloat x = self.userNameLTView.frame.origin.x;
CGFloat y = self.userNameLTView.frame.origin.y;

根据上一个视图的位置创建另一个自定义视图
self.passwordLTView = [[LTView alloc] initWithFrame:CGRectMake(x,y + height + 30,width, height)];

将先创建的自定义视图添加在本自定义视图
[self addSubview:self.passwordLTView];

释放
[_passwordLTView release];

循环创建Button
for (int i = 0; i < 3; i++) {
UIButton *button = [UIButton buttonWithType:(UIButtonTypeCustom)];

使三个Button的位置平行不叠加
button.frame = CGRectMake(45 + (i * 100), 300, 90, 50);

加标签 方便取出Button 与属性Button 相对应
button.tag = i + 100;

添加到本自定义视图上
[self addSubview:button];

}

属性与循环的Button 进行关联
self.loginButton = (UIButton *)[self viewWithTag:100];
self.registerButton = (UIButton *)[self viewWithTag:101];
self.retrieveButton = (UIButton *)[self viewWithTag:102];
}
return self;

}