iOS ?常用方法

1.在自定義View中跳轉(zhuǎn)到其他控制器

[[self viewController].navigationController pushViewController:allPatientVC animated:YES];

- (UIViewController *)viewController {
for (UIView* next = [self superview]; next; next = next.superview) {
    UIResponder *nextResponder = [next nextResponder];
    if ([nextResponder isKindOfClass:[UIViewController class]]) {
        return (UIViewController *)nextResponder;
    }
}
return nil;
}

2.設(shè)置UITableView分割線位置

//1.調(diào)整(iOS7以上)表格分隔線邊距
if ([self.tableView   respondsToSelector:@selector(setSeparatorInset:)]) {
  self.tableView.separatorInset = UIEdgeInsetsZero;
}
//2.調(diào)整(iOS8以上)view邊距(或者在cell中設(shè)置preservesSuperviewLayoutMargins,二者等效)
if ([self.tableView respondsToSelector:@selector(setLayoutMargins:)]) {
  self.tableView.layoutMargins = UIEdgeInsetsZero;
}

3.修改UITextField的占位符的字體顏色和大小

方法1:利用富文本

@property (weak, nonatomic) IBOutlet UITextField *textField;

NSDictionary *dic = @{NSForegroundColorAttributeName:[UIColor magentaColor], NSFontAttributeName:[UIFont systemFontOfSize:15]};

self.textField.attributedPlaceholder = [[NSAttributedString alloc] initWithString:@"歡迎回來" attributes:dic];

self.textField.tintColor = [UIColor cyanColor];



方法2:KVC

self.textField.placeholder = @"歡迎回來!";

[self.textField setValue:[UIColor magentaColor] forKeyPath:@"_placeholderLabel.textColor"]

[self.textField setValue:[UIFont systemFontOfSize:15] forKeyPath:@"_placeholderLabel.font"];

self.textField.tintColor = [UIColor greenColor];

4.修改導(dǎo)航欄item的左右間距

UIBarButtonItem *rightSpace = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemFixedSpace target:nil action:nil];

rightSpace.width = -7;

self.navigationItem.rightBarButtonItems = @[rightSpace,rightItem];

5.UIButton 左邊圖片，右邊文字

UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
button.frame = CGRectMake(100, 100, 100, 50);
button.backgroundColor = [UIColor clearColor];
//設(shè)置button正常狀態(tài)下的圖片
[button setImage:[UIImage imageNamed:@"_star_normal.png"]    forState:UIControlStateNormal];
//設(shè)置button高亮狀態(tài)下的圖片
[button setImage:[UIImage imageNamed:@"_star_highlighted.png"] forState:UIControlStateHighlighted];
//設(shè)置button正常狀態(tài)下的背景圖
[button setBackgroundImage:[UIImage imageNamed:@"_normal.png"] forState:UIControlStateNormal];
//設(shè)置button高亮狀態(tài)下的背景圖
[button setBackgroundImage:[UIImage imageNamed:@"_highlighted.png"] forState:UIControlStateHighlighted];
//button圖片的偏移量，距上左下右分別(10, 10, 10, 60)像素點
button.imageEdgeInsets = UIEdgeInsetsMake(10, 10, 10, 60);
[button setTitle:@"南瓜瓜" forState:UIControlStateNormal];
//button標(biāo)題的偏移量，這個偏移量是相對于圖片的
button.titleEdgeInsets = UIEdgeInsetsMake(0, -20, 0, 0);
//設(shè)置button正常狀態(tài)下的標(biāo)題顏色
[button setTitleColor:[UIColor redColor] forState:UIControlStateNormal];
//設(shè)置button高亮狀態(tài)下的標(biāo)題顏色
[button setTitleColor:[UIColor greenColor] forState:UIControlStateHighlighted];
button.titleLabel.font = [UIFont systemFontOfSize:14];
[self.view addSubview:button];

6.檢查字符串是否為url

- (NSString *)getCompleteWebsite:(NSString *)urlStr{  
NSString *returnUrlStr = nil;  
NSString *scheme = nil;  
  
assert(urlStr != nil);  
  
urlStr = [urlStr stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];  
if ( (urlStr != nil) && (urlStr.length != 0) ) {  
    NSRange  urlRange = [urlStr rangeOfString:@"://"];  
    if (urlRange.location == NSNotFound) {  
        returnUrlStr = [NSString stringWithFormat:@"http://%@", urlStr];  
    } else {  
        scheme = [urlStr substringWithRange:NSMakeRange(0, urlRange.location)];  
        assert(scheme != nil);  
          
        if ( ([scheme compare:@"http"  options:NSCaseInsensitiveSearch] == NSOrderedSame)  
            || ([scheme compare:@"https" options:NSCaseInsensitiveSearch] == NSOrderedSame) ) {  
            returnUrlStr = urlStr;  
        } else {  
            //不支持的URL方案  
        }  
    }  
}  
return returnUrlStr;  
}

7.秒轉(zhuǎn)換為時分秒

-(NSString *)getMMSSFromSS:(NSString *)totalTime{

 NSInteger seconds = [totalTime integerValue];
//format of hour
NSString *str_hour = [NSString stringWithFormat:@"%02ld",seconds/3600];
//format of minute
NSString *str_minute = [NSString stringWithFormat:@"%02ld",(seconds%3600)/60];
//format of second
NSString *str_second = [NSString stringWithFormat:@"%02ld",seconds%60];
//format of time
NSString *format_time = [NSString stringWithFormat:@"%@:%@:%@",str_hour,str_minute,str_second];
return format_time;
}`

8.禁用系統(tǒng)左滑返回

- (void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
// 禁用返回手勢
if ([self.navigationController respondsToSelector:@selector(interactivePopGestureRecognizer)]) {
    self.navigationController.interactivePopGestureRecognizer.enabled = NO;
}
}

- (void)viewWillDisappear:(BOOL)animated
{
[super viewWillDisappear:animated];
// 開啟返回手勢
if ([self.navigationController respondsToSelector:@selector(interactivePopGestureRecognizer)]) {
    self.navigationController.interactivePopGestureRecognizer.enabled = YES;
}
}

9.判斷UIImage圖片是否是同一張圖片（在寫UIImagePickerController中要判斷之前的image和當(dāng)下選擇的uiimage是不是一個image）

UIImage* image= info[UIImagePickerControllerOriginalImage];
UIImageView* imageView=[[UIImageView alloc]initWithFrame:CGRectMake(self.imageViews.count*80.0, 0, 80, 80)];
   imageView.image=image;
for (UIImageView* subimage in self.imageViews) {
    if ([UIImagePNGRepresentation(subimage.image) isEqual:UIImagePNGRepresentation(image)]) {
        UIAlertView* alert=[[UIAlertView alloc]initWithTitle:@" 此圖片已經(jīng)選擇過，選擇其他圖片" message:@" 此圖片已經(jīng)選擇過，選擇其他圖片"  delegate:self cancelButtonTitle:@"cancel" otherButtonTitles:@"ok ", nil];
        [alert show];
        return;
    }
}

10.真色彩顯示

真彩色的顯示會根據(jù)光感應(yīng)器來自動的調(diào)節(jié)達(dá)到特定環(huán)境下顯示與性能的平衡效果,如果需要這個功能的話,可以在info.plist里配置(在Source Code模式下):

  <key>UIWhitePointAdaptivityStyle</key>
  它有五種取值,分別是:

  <string>UIWhitePointAdaptivityStyleStandard</string> // 標(biāo)準(zhǔn)模式
  <string>UIWhitePointAdaptivityStyleReading</string> // 閱讀模式
  <string>UIWhitePointAdaptivityStylePhoto</string> // 圖片模式
  <string>UIWhitePointAdaptivityStyleVideo</string> // 視頻模式
  <string>UIWhitePointAdaptivityStyleStandard</string> // 游戲模式

也就是說如果你的項目是閱讀類的,就選擇UIWhitePointAdaptivityStyleReading這個模式,五種模式的顯示效果是從上往下遞減,也就是說如果你的項目是圖片處理類的,你選擇的是閱讀模式,給選擇太好的效果會影響性能.

11.UIRefreshControl

在iOS 10 中, UIRefreshControl可以直接在UICollectionView和UITableView中使用,并且脫離了UITableViewController.現(xiàn)在RefreshControl是UIScrollView的一個屬性.
使用方法:

  UIRefreshControl *refreshControl = [[UIRefreshControl alloc] init];
  [refreshControl addTarget:self action:@selector(loadData)      forControlEvents:UIControlEventValueChanged];
  collectionView.refreshControl = refreshControl;

12 UIImage圖片轉(zhuǎn)成Base64字符串：

UIImage *originImage = [UIImage imageNamed:@"Cover.png"];

NSData *data = UIImageJPEGRepresentation(originImage, 1.0f);

NSString *encodedImageStr = [data base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
NSLog(@"encodedImageStr==%@",encodedImageStr);

//Base64字符串轉(zhuǎn)UIImage圖片：

NSData *decodedImageData = [[NSData alloc]initWithBase64EncodedString:encodedImageStr options:NSDataBase64DecodingIgnoreUnknownCharacters];

UIImage *decodedImage = [UIImage imageWithData:decodedImageData];

UIImageView *imgView = [[UIImageView alloc] initWithFrame:CGRectMake(60, 100, 200, 400)];

[imgView setImage:decodedImage];

[self.view addSubview:imgView];

NSLog(@"decodedImage==%@",decodedImageData);

13.iOS如何快速得到數(shù)組所有元素累加結(jié)果，平均值和最大最小值

NSArray *values = @[@72, @78, @75, @70, @72, @73, @77, @78, @75, @70, @72, @73, @87, @78, @75, @70, @72];

NSNumber *avg = [values valueForKeyPath:@"@avg.self"];

NSNumber *sum = [values valueForKeyPath:@"@sum.self"];

NSNumber *max = [values valueForKeyPath:@"@max.self"];

NSNumber *min = [values valueForKeyPath:@"@min.self"];

14.隱藏導(dǎo)航欄

    @interface WLHomePageController () <UINavigationControllerDelegate>

    @end

    @implementation WLHomePageController 

    #pragma mark - lifeCycle
    - (void)viewDidLoad {
    [super viewDidLoad];
    // 設(shè)置導(dǎo)航控制器的代理為self
    self.navigationController.delegate = self;
  }

  #pragma mark - UINavigationControllerDelegate
// 將要顯示控制器
- (void)navigationController:(UINavigationController *)navigationController   willShowViewController:(UIViewController *)viewController animated:(BOOL)animated {
    // 判斷要顯示的控制器是否是自己
    BOOL isShowHomePage = [viewController isKindOfClass:[self class]];

    [self.navigationController setNavigationBarHidden:isShowHomePage animated:YES];
}

- (void)dealloc {
    self.navigationController.delegate = nil;
}

15.防止scrollView手勢覆蓋側(cè)滑手勢

[scrollView.panGestureRecognizerrequireGestureRecognizerToFail:self.navigationController.interactivePopGestureRecognizer];

16.字符串中是否含有中文

+ (BOOL)checkIsChinese:(NSString *)string
{
for (int i=0; i<string.length; i++)
{
    unichar ch = [string characterAtIndex:i];
    if (0x4E00 <= ch  && ch <= 0x9FA5)
    {
        return YES;
    }
}
return NO;
}
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