04-UIKit（UINavigationController、NSAttributeString、UIImageView）
目录：
一、UINavigationController导航视图控制器
一、UINavigationController导航视图控制器
1 定义：导航视图控制器是控制另外控制器的控制器
2 作用：导航，管理多个视图控制器的跳转，比如我们自己控制视图控制器的跳转更清晰
3 怎么用：创建UINavigationController有一个初始化方法initWithRootViewController：被控制的控制器
* 把navigationcontroller设置成window的根视图
* 从navigationcontroller中跳转到另一个视图控制器：pushViewController
* 从navigationcontroller返回上一个视图控制器：popViewController
在storyboard中设置navigation
editor -> embedin -> navigationController
4 在empty中使用代码添加navigation
在AppDelegate.m中
//UINavigationController
MXFistViewController* fistViewController = [[MXFistViewController alloc] initWithNibName:@"MXFistViewController" bundle:nil];
UINavigationController *navi = [[UINavigationController alloc] initWithRootViewController:fistViewController];
self.window.rootViewController = navi;
5 内部原理
＊ navigation根view不能pop
＊ navigation维护着一个VC栈，先进后出
＊ navi必须有一个根视图，创建navi时一般会直接指定
＊ push一个VC时，上一个VC不会被释放
＊ navi会保存push进去的VC引用计数器
＊ pop出来的VC会立即被释放
＊ 不能pop根视图
6 深入理解navi
＊ .title .leftBarButtonItem .leftBarButtonItems .toolBarItems这些属性设置在具体的某一个被navi包含的VC，不是设置在navi上
＊ 具体的VC 上的toolbar默认是隐藏的，如果显示需要调用一个方法[self.navigationController setToolbarHidden:NO]
＊ UIBarButtonItem 不管是Navigation还是toolbar其中的按键都要用UIBarButton
initWithSystemItem:...设置系统内置按钮
initWithTitle:...文字按钮
initWithImage...图片按钮
- (void)viewDidLoad
{
[super viewDidLoad];
//设置navigation标题
self.title = @"好友圈";
//设置navigation左右按钮
self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemCompose target:self action:@selector(writeWeibo:)];
//self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:nil action:nil];
UIBarButtonItem *button1 = [[UIBarButtonItem alloc] initWithTitle:@"one" style:UIBarButtonItemStyleBordered target:nil action:nil];
UIBarButtonItem *button2 = [[UIBarButtonItem alloc] initWithTitle:@"two" style:UIBarButtonItemStylePlain target:nil action:nil];
self.navigationItem.rightBarButtonItems = @[button1,button2];
//工具条
UIBarButtonItem* button3 = [[UIBarButtonItem alloc] initWithTitle:@"首页" style:UIBarButtonItemStyleBordered target:nil action:nil];
UIBarButtonItem* button4 = [[UIBarButtonItem alloc] initWithTitle:@"消息" style:UIBarButtonItemStyleBordered target:nil action:nil];
//fixed固定
UIBarButtonItem* fixed = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFixedSpace target:nil action:nil];
fixed.width = 20;//设置固定宽度
//flexible灵活
UIBarButtonItem* flexible = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:nil action:nil];
//添加工具条中的按钮
self.toolbarItems = @[fixed,button3,flexible,button4,fixed];
// Do any additional setup after loading the view from its nib.
}
-(void)viewWillAppear:(BOOL)animated{
[super viewWillAppear:animated];
//显示工具条
[self.navigationController setToolbarHidden:NO animated:YES];
}
-(void)writeWeibo:(UIBarButtonItem*)button{
MXSecondViewController* second = [[MXSecondViewController alloc] initWithNibName:@"MXSecondViewController" bundle:nil];
//跳转到另一个view
//[self.navigationController pushViewController:second animated:YES];
//跳转到被navigation包含的一个view
UINavigationController *navi = [[UINavigationController alloc] initWithRootViewController:second];
[self presentViewController:navi animated:YES completion:nil];
}
二、NSAttributeString属性字符串
1 ios6中开始ios7加强
2 在NSString的基础上，加入了属性的功能，字体，颜色，加粗，描边，等
MXAttributeViewController.m
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view from its nib.
[self setup];
UIBarButtonItem* button = [[UIBarButtonItem alloc] initWithTitle:@"stats" style:UIBarButtonItemStyleBordered target:self action:@selector(statsTap:)];
//设置导航控制器的右边的button
self.navigationItem.rightBarButtonItem = button;
}
-(void)statsTap:(UIBarButtonItem*)button{
MXTextStatsViewController *text = [[MXTextStatsViewController alloc] initWithNibName:@"MXTextStatsViewController" bundle:nil];
text.textToAnglyze = self.body.textStorage;//传值
//
[self.navigationController pushViewController:text animated:YES];
}
-(void)setup{
NSMutableAttributedString *title = [[NSMutableAttributedString alloc] initWithString:@"outline" attributes:@{NSStrokeWidthAttributeName: @-3,NSStrokeColorAttributeName:self.outlineButton.tintColor}];
[self.outlineButton setAttributedTitle:title forState:UIControlStateNormal];
}
//改变textView中被选择字体颜色
- (IBAction)changeSelectedColor:(UIButton *)sender {
//Storage中文是存储 仓库
[self.body.textStorage addAttribute:NSForegroundColorAttributeName value:sender.backgroundColor range:self.body.selectedRange];
}
//加粗textView中被选择字体
- (IBAction)outlineSelect:(UIButton *)sender {
//[self.body.textStorage addAttributes:@{NSStrokeColorAttributeName: [UIColor blackColor],NSStrokeWidthAttributeName:[NSNumber numberWithInteger:3]} range:self.body.selectedRange];
[self.body.textStorage addAttributes:@{NSStrokeColorAttributeName: [UIColor blackColor],NSStrokeWidthAttributeName:@-3} range:self.body.selectedRange];
}
//取消加粗
- (IBAction)unoutlineSelect:(UIButton *)sender {
[self.body.textStorage removeAttribute:NSStrokeWidthAttributeName range:self.body.selectedRange];
}
MXTextStatsViewController.m
-(void)viewWillAppear:(BOOL)animated{
[super viewWillAppear:animated];
[self updateUI];
}
-(void)updateUI{
self.colorfulLabel.text = [NSString stringWithFormat:@"%d colorful charactrors",[self charactersWithAttribute:NSForegroundColorAttributeName].length];
self.outlineLabel.text = [NSString stringWithFormat:@"%d outline charactors",[self charactersWithAttribute:NSStrokeWidthAttributeName].length];
}
//
-(NSAttributedString*)charactersWithAttribute:(NSString*)attributeName{
//创建属性字符串
NSMutableAttributedString *characters = [[NSMutableAttributedString alloc] init];
NSUInteger index = 0;
while ([self.textToAnglyze length] > index) {
NSRange range;
//把下标为index有attributeName这个属性的位置和长度 保存在range指向的地址中
id value = [self.textToAnglyze attribute:attributeName atIndex:index effectiveRange:&range];
if (value) {
//添加range范围内的属性字符串到characters
[characters appendAttributedString:[self.textToAnglyze attributedSubstringFromRange:range]];
index = range.location + range.length;
}else{
index++;
}
}
return characters;
}
知识点
设置label属性使用attributedText
设置textView属性使用textStorage
三、UIImageView图像处理
contentMode属性，设置图片形状
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
UIImage *image = [UIImage imageNamed:@"0.png"];
UIImageView *imageView = [[UIImageView alloc]initWithImage:image];
//设置
imageView.frame = self.view.frame;
imageView.contentMode = UIViewContentModeScaleAspectFit;
[self.view addSubview:imageView];
}
1 代码创建UIImageView，frame默认是图片的大小，.contentMode默认是拉伸，frame如果和图片大小不一致拉伸图片
mode风格
UIViewContentModeScaleToFill,默认拉伸
UIViewContentModeScaleAspectFit, 保持宽高比 ，完全显示，留边
UIViewContentModeScaleAspectFill, 保持宽高比，铺满imageview
Redraw做绘制时使用
UIImageView图片视图控件
＊ 在界面上的有限空间中显示超过界面大小的内容，（图片，文本）UITextView 是UIScrollView的子类
＊ 重要属性
.frame -> scrollView在界面上的实际大小和坐标
.contentSize -> scrollView需要显示的内容大小
一般情况下，内容的大小大于frame的大小，以达到滚动效果
注意：这两个属性一定都要设置，否则看不到
＊ 支持缩放的属性
minimumZoomScale:设置最小的缩放比例
maximumZoomScale:设置最大的缩放比例，一般为1.0
//水平方向缩放比例
float horizontalScale = scrollView.frame.size.width / self.imageView.frame.size.width;
//垂直方向缩放比例
float vertical = scrollView.frame.size.height / self.imageView.frame.size.height;
//比较水平和垂直方向哪个最小
float minimumZoomScale = MIN(horizontalScale, vertical);
//缩放最小值
scrollView.minimumZoomScale = minimumZoomScale;
//缩放最大值
scrollView.maximumZoomScale = MAX_SCALE;
scrollView.delegate = self;
//scrollview代理中进行缩放的方法，返回一个view进行缩放 按住alt健进行缩放操作
-(UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView{
return self.imageView;
}
＊ 其他属性
. showsHorizontalScrollIndicator显示横条
. showsVerticalScrollIndicato 显示竖条
. pagingEnable启动分页控制
. contentInset 内边距
. scrollIndicatorInsets 滚轴的内边距
scrollView.scrollIndicatorInsets = UIEdgeInsetsMake(10, 0, 0, 0);
＊ 委托协议UIScrollViewDelegate
返回哪一个子视图进行缩放：
缩放开始时调用的方法/结束时调用的方法
-(UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
作业：视力检查表，
Label.font = [UIFont systemFontSize:100];
界面1：label的字体大小是100 E
按钮 看得见 点击进入
界面2：90 E
按钮 看得见 点击进入
界面3：80 E
。。。
看不见显示结果
- (void)viewDidLoad
{
[super viewDidLoad];
self.lableE.font = [UIFont systemFontOfSize:100 - self.size2];
// Do any additional setup after loading the view from its nib.
}
- (IBAction)lookSee:(UIButton *)sender {
self.size2 += 10;
MXViewController *viewController = [[MXViewController alloc] initWithNibName:@"MXViewController" bundle:nil];
viewController.size2 = self.size2;
[self.navigationController pushViewController:viewController animated:YES];
}
- (IBAction)noLookSee:(UIButton *)sender {
NSLog(@"看不见了，您的视力是:%d",100 - self.size2);
}
