iOS开发常用代码块

遍历可变数组的同时删除数组元素

NSMutableArray *copyArray = [NSMutableArray arrayWithArray:array];
NSString *str1 = @“zhangsan”;
for (AddressPerson *perName in copyArray) {
if ([[perName name] isEqualToString:str1]) {
[array removeObject:perName];
}
}

获取系统当前语言

NSString *currentLanguage = [[NSLocale preferredLanguages] objectAtIndex:];
NSLog(@"currentlanguage = %@",currentLanguage); if ([currentLanguage containsString:@"zh-Hans"]) {
NSLog(@"zh-Hans简体中文");
}else if ([currentLanguage containsString:@"zh-Hant"]) {
NSLog(@"zh-Hant繁体中文");
}

UITableView的Group样式下顶部空白处理

UIView *view = [[UIView alloc] initWithFrame:CGRectMake(, , , 0.1)];
self.tableView.tableHeaderView = view;

UITableView的plain样式下,取消区头停滞效果

- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
CGFloat sectionHeaderHeight = sectionHead.height;
if (scrollView.contentOffset.y<=sectionHeaderHeight&&scrollView;.contentOffset.y>=)
{
scrollView.contentInset = UIEdgeInsetsMake(-scrollView.contentOffset.y, , , );
}
else if(scrollView.contentOffset.y>=sectionHeaderHeight)
{
scrollView.contentInset = UIEdgeInsetsMake(-sectionHeaderHeight, , , );
}
}

获取某个view所在的控制器

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

两种方法删除NSUserDefaults所有记录

//方法一
NSString *appDomain = [[NSBundle mainBundle] bundleIdentifier];
[[NSUserDefaults standardUserDefaults] removePersistentDomainForName:appDomain]; //方法二
- (void)resetDefaults
{
NSUserDefaults * defs = [NSUserDefaults standardUserDefaults];
NSDictionary * dict = [defs dictionaryRepresentation];
for (id key in dict)
{
[defs removeObjectForKey:key];
}
[defs synchronize];
}

打印系统所有已注册的字体名称

void enumerateFonts()
{
for(NSString *familyName in [UIFont familyNames])
{
NSLog(@"%@",familyName);
NSArray *fontNames = [UIFont fontNamesForFamilyName:familyName];
for(NSString *fontName in fontNames)
{
NSLog(@"\t|- %@",fontName);
}
}
}

获取图片某一点的颜色

- (UIColor*) getPixelColorAtLocation:(CGPoint)point inImage:(UIImage *)image
{ UIColor* color = nil;
CGImageRef inImage = image.CGImage;
CGContextRef cgctx = [self createARGBBitmapContextFromImage:inImage]; if (cgctx == NULL) {
return nil; /* error */
}
size_t w = CGImageGetWidth(inImage);
size_t h = CGImageGetHeight(inImage);
CGRect rect = {{,},{w,h}}; CGContextDrawImage(cgctx, rect, inImage);
unsigned char* data = CGBitmapContextGetData (cgctx);
if (data != NULL) {
int offset = *((w*round(point.y))+round(point.x));
int alpha = data[offset];
int red = data[offset+];
int green = data[offset+];
int blue = data[offset+];
color = [UIColor colorWithRed:(red/255.0f) green:(green/255.0f) blue:
(blue/255.0f) alpha:(alpha/255.0f)];
}
CGContextRelease(cgctx);
if (data) {
free(data);
}
return color;
}

字符串反转

//第一种:
- (NSString *)reverseWordsInString:(NSString *)str
{
NSMutableString *newString = [[NSMutableString alloc] initWithCapacity:str.length];
for (NSInteger i = str.length - ; i >= ; i --)
{
unichar ch = [str characterAtIndex:i];
[newString appendFormat:@"%c", ch];
}
return newString;
} //第二种:
- (NSString*)reverseWordsInString:(NSString*)str
{
NSMutableString *reverString = [NSMutableString stringWithCapacity:str.length];
[str enumerateSubstringsInRange:NSMakeRange(, str.length) options:NSStringEnumerationReverse | NSStringEnumerationByComposedCharacterSequences usingBlock:^(NSString *substring, NSRange substringRange, NSRange enclosingRange, BOOL *stop) {
[reverString appendString:substring];
}];
return reverString;
}

禁止锁屏

//第一种
[UIApplication sharedApplication].idleTimerDisabled = YES;
//第二种
[[UIApplication sharedApplication] setIdleTimerDisabled:YES];

模态推出透明界面

UIViewController *vc = [[UIViewController alloc] init];
UINavigationController *na = [[UINavigationController alloc] initWithRootViewController:vc]; if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 8.0)
{
na.modalPresentationStyle = UIModalPresentationOverCurrentContext;
}
else
{
self.modalPresentationStyle=UIModalPresentationCurrentContext;
} [self presentViewController:na animated:YES completion:nil];

iOS跳转到App Store下载应用评分

[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"itms-apps://itunes.apple.com/WebObjects/MZStore.woa/wa/viewContentsUserReviews?type=Purple+Software&id=APPID"]];

手动更改iOS状态栏的颜色

- (void)setStatusBarBackgroundColor:(UIColor *)color
{
UIView *statusBar = [[[UIApplication sharedApplication] valueForKey:@"statusBarWindow"] valueForKey:@"statusBar"]; if ([statusBar respondsToSelector:@selector(setBackgroundColor:)])
{
statusBar.backgroundColor = color;
}
}

判断当前ViewController是push还是present的方式显示

NSArray *viewcontrollers=self.navigationController.viewControllers;

if (viewcontrollers.count > )
{
if ([viewcontrollers objectAtIndex:viewcontrollers.count - ] == self)
{
//push方式
[self.navigationController popViewControllerAnimated:YES];
}
}
else
{
//present方式
[self dismissViewControllerAnimated:YES completion:nil];
}

获取实际使用的LaunchImage图片

- (NSString *)getLaunchImageName
{
CGSize viewSize = self.window.bounds.size;
// 竖屏
NSString *viewOrientation = @"Portrait";
NSString *launchImageName = nil;
NSArray* imagesDict = [[[NSBundle mainBundle] infoDictionary] valueForKey:@"UILaunchImages"];
for (NSDictionary* dict in imagesDict)
{
CGSize imageSize = CGSizeFromString(dict[@"UILaunchImageSize"]);
if (CGSizeEqualToSize(imageSize, viewSize) && [viewOrientation isEqualToString:dict[@"UILaunchImageOrientation"]])
{
launchImageName = dict[@"UILaunchImageName"];
}
}
return launchImageName;
}

iOS在当前屏幕获取第一响应

UIWindow * keyWindow = [[UIApplication sharedApplication] keyWindow];
UIView * firstResponder = [keyWindow performSelector:@selector(firstResponder)];

判断对象是否遵循了某协议

if ([self.selectedController conformsToProtocol:@protocol(RefreshPtotocol)])
{
[self.selectedController performSelector:@selector(onTriggerRefresh)];
}

判断view是不是指定视图的子视图

BOOL isView = [textView isDescendantOfView:self.view];

NSArray 快速求总和 最大值 最小值 和 平均值

NSArray *array = [NSArray arrayWithObjects:@"2.0", @"2.3", @"3.0", @"4.0", @"", nil];
CGFloat sum = [[array valueForKeyPath:@"@sum.floatValue"] floatValue];
CGFloat avg = [[array valueForKeyPath:@"@avg.floatValue"] floatValue];
CGFloat max =[[array valueForKeyPath:@"@max.floatValue"] floatValue];
CGFloat min =[[array valueForKeyPath:@"@min.floatValue"] floatValue];
NSLog(@"%f\n%f\n%f\n%f",sum,avg,max,min);

修改UITextField中Placeholder的文字颜色

[textField setValue:[UIColor redColor] forKeyPath:@"_placeholderLabel.textColor"];

获取一个类的所有子类

+ (NSArray *) allSubclasses
{
Class myClass = [self class];
NSMutableArray *mySubclasses = [NSMutableArray array];
unsigned int numOfClasses;
Class *classes = objc_copyClassList(&numOfClasses;);
for (unsigned int ci = ; ci < numOfClasses; ci++)
{
Class superClass = classes[ci];
do{
superClass = class_getSuperclass(superClass);
} while (superClass && superClass != myClass); if (superClass)
{
[mySubclasses addObject: classes[ci]];
}
}
free(classes);
return mySubclasses;
}

阿拉伯数字转中文格式

+(NSString *)translation:(NSString *)arebic
{
NSString *str = arebic;
NSArray *arabic_numerals = @[@"",@"",@"",@"",@"",@"",@"",@"",@"",@""];
NSArray *chinese_numerals = @[@"一",@"二",@"三",@"四",@"五",@"六",@"七",@"八",@"九",@"零"];
NSArray *digits = @[@"个",@"十",@"百",@"千",@"万",@"十",@"百",@"千",@"亿",@"十",@"百",@"千",@"兆"];
NSDictionary *dictionary = [NSDictionary dictionaryWithObjects:chinese_numerals forKeys:arabic_numerals]; NSMutableArray *sums = [NSMutableArray array];
for (int i = ; i < str.length; i ++) {
NSString *substr = [str substringWithRange:NSMakeRange(i, )];
NSString *a = [dictionary objectForKey:substr];
NSString *b = digits[str.length -i-];
NSString *sum = [a stringByAppendingString:b];
if ([a isEqualToString:chinese_numerals[]])
{
if([b isEqualToString:digits[]] || [b isEqualToString:digits[]])
{
sum = b;
if ([[sums lastObject] isEqualToString:chinese_numerals[]])
{
[sums removeLastObject];
}
}else
{
sum = chinese_numerals[];
} if ([[sums lastObject] isEqualToString:sum])
{
continue;
}
} [sums addObject:sum];
} NSString *sumStr = [sums componentsJoinedByString:@""];
NSString *chinese = [sumStr substringToIndex:sumStr.length-];
NSLog(@"%@",str);
NSLog(@"%@",chinese);
return chinese;
}

取消UICollectionView的隐式动画

//方法一
[UIView performWithoutAnimation:^{
[collectionView reloadItemsAtIndexPaths:@[[NSIndexPath indexPathForItem:index inSection:]]];
}]; //方法二
[UIView animateWithDuration: animations:^{
[collectionView performBatchUpdates:^{
[collectionView reloadItemsAtIndexPaths:@[[NSIndexPath indexPathForItem:index inSection:]]];
} completion:nil];
}]; //方法三
[UIView setAnimationsEnabled:NO];
[self.trackPanel performBatchUpdates:^{
[collectionView reloadItemsAtIndexPaths:@[[NSIndexPath indexPathForItem:index inSection:]]];
} completion:^(BOOL finished) {
[UIView setAnimationsEnabled:YES];
}];

判断邮箱格式是否正确的代码

-(BOOL)isValidateEmail:(NSString *)email

  {

  NSString *emailRegex = @"[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,4}";

  NSPredicate *emailTest = [NSPredicate predicateWithFormat:@"SELF MATCHES%@",emailRegex];

  return [emailTest evaluateWithObject:email];

  }

iOS中UITextField的字数限制

//在viewDidLoad中注册<UITextFieldTextDidChangeNotification>通知
[[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(textFiledEditChanged:)
name:@"UITextFieldTextDidChangeNotification" object:myTextField];
//实现监听方法
#pragma mark - Notification Method
-(void)textFieldEditChanged:(NSNotification *)obj
{
UITextField *textField = (UITextField *)obj.object;
NSString *toBeString = textField.text; //获取高亮部分
UITextRange *selectedRange = [textField markedTextRange];
UITextPosition *position = [textField positionFromPosition:selectedRange.start offset:]; // 没有高亮选择的字,则对已输入的文字进行字数统计和限制
if (!position)
{
if (toBeString.length > MAX_STARWORDS_LENGTH)
{
NSRange rangeIndex = [toBeString rangeOfComposedCharacterSequenceAtIndex:MAX_STARWORDS_LENGTH];
if (rangeIndex.length == )
{
textField.text = [toBeString substringToIndex:MAX_STARWORDS_LENGTH];
}
else
{
NSRange rangeRange = [toBeString rangeOfComposedCharacterSequencesForRange:NSMakeRange(, MAX_STARWORDS_LENGTH)];
textField.text = [toBeString substringWithRange:rangeRange];
}
}
}
}

小伙伴们,今天就分享到这里,下期更精彩!

上一篇:线段树+离散化 IP地址段检查 SEGMENT TREE


下一篇:Windows的命令行查看,修改,删除,添加环境变量