iOS 小技巧總結，絕對有你想要的
在這里總結一些iOS開發中的小技巧，能大大方便我們的開發，持續更新。
UITableView的Group樣式下頂部空白處理
//分組列表頭部空白處理
UIView *view = [[UIViewalloc] initWithFrame:CGRectMake(0, 0, 0, 0.1)];
self.tableView.tableHeaderView = view;
UITableView的plain樣式下，取消區頭停滯效果
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
CGFloatsectionHeaderHeight = sectionHead.height;
if (scrollView.contentOffset.y=0)
{
scrollView.contentInset = UIEdgeInsetsMake(-scrollView.contentOffset.y, 0, 0, 0);
}
else if(scrollView.contentOffset.y>=sectionHeaderHeight)
{
scrollView.contentInset = UIEdgeInsetsMake(-sectionHeaderHeight, 0, 0, 0);
}
}
那個，其實，還是用Group樣式吧哈哈。
獲取某個view所在的控制器
- (UIViewController *)viewController
{
UIViewController *viewController = nil;
UIResponder *next = self.nextResponder;
while (next)
{
if ([nextisKindOfClass:[UIViewControllerclass]])
{
viewController = (UIViewController *)next;
break;
}
next = next.nextResponder;
}
return viewController;
}
兩種方法刪除NSUserDefaults所有記錄
//方法一
NSString *appDomain = [[NSBundlemainBundle] bundleIdentifier];
[[NSUserDefaultsstandardUserDefaults] removePersistentDomainForName:appDomain];
//方法二
- (void)resetDefaults
{
NSUserDefaults * defs = [NSUserDefaultsstandardUserDefaults];
NSDictionary * dict = [defsdictionaryRepresentation];
for (idkeyin dict)
{
[defsremoveObjectForKey:key];
}
[defssynchronize];
}
打印系統所有已注冊的字體名稱
#pragma mark - 打印系統所有已注冊的字體名稱
void enumerateFonts()
{
for(NSString *familyNamein [UIFontfamilyNames])
{
NSLog(@"%@",familyName);
NSArray *fontNames = [UIFontfontNamesForFamilyName:familyName];
for(NSString *fontNamein fontNames)
{
NSLog(@"\t|- %@",fontName);
}
}
}
獲取圖片某一點的顏色
- (UIColor*) getPixelColorAtLocation:(CGPoint)pointinImage:(UIImage *)image
{
UIColor* color = nil;
CGImageRefinImage = image.CGImage;
CGContextRefcgctx = [self createARGBBitmapContextFromImage:inImage];
if (cgctx == NULL) {
return nil; /* error */
}
size_t w = CGImageGetWidth(inImage);
size_t h = CGImageGetHeight(inImage);
CGRectrect = {{0,0},{w,h}};
CGContextDrawImage(cgctx, rect, inImage);
unsigned char* data = CGBitmapContextGetData (cgctx);
if (data != NULL) {
int offset = 4*((w*round(point.y))+round(point.x));
int alpha = data[offset];
int red = data[offset+1];
int green = data[offset+2];
int blue = data[offset+3];
color = [UIColorcolorWithRed:(red/255.0f) green:(green/255.0f) blue:
(blue/255.0f) alpha:(alpha/255.0f)];
}
CGContextRelease(cgctx);
if (data) {
free(data);
}
return color;
}
字符串反轉
第一種：
- (NSString *)reverseWordsInString:(NSString *)str
{
NSMutableString *newString = [[NSMutableStringalloc] initWithCapacity:str.length];
for (NSInteger i = str.length - 1; i >= 0 ; i --)
{
unicharch = [strcharacterAtIndex:i];
[newStringappendFormat:@"%c", ch];
}
return newString;
}
//第二種：
- (NSString*)reverseWordsInString:(NSString*)str
{
NSMutableString *reverString = [NSMutableStringstringWithCapacity:str.length];
[strenumerateSubstringsInRange:NSMakeRange(0, str.length) options:NSStringEnumerationReverse | NSStringEnumerationByComposedCharacterSequences usingBlock:^(NSString *substring, NSRangesubstringRange, NSRangeenclosingRange, BOOL *stop) {
[reverStringappendString:substring];
}];
return reverString;
}
禁止鎖屏，
默認情況下，當設備一段時間沒有觸控動作時，iOS會鎖住屏幕。但有一些應用是不需要鎖屏的，比如視頻播放器。
[UIApplicationsharedApplication].idleTimerDisabled = YES;
或
[[UIApplicationsharedApplication] setIdleTimerDisabled:YES];
模態推出透明界面
UIViewController *vc = [[UIViewControlleralloc] init];
UINavigationController *na = [[UINavigationControlleralloc] initWithRootViewController:vc];
if ([[[UIDevicecurrentDevice] systemVersion] floatValue] >= 8.0)
{
na.modalPresentationStyle = UIModalPresentationOverCurrentContext;
}
else
{
self.modalPresentationStyle=UIModalPresentationCurrentContext;
}
[self presentViewController:naanimated:YEScompletion:nil];
Xcode調試不顯示內存占用
editSCheme 里面有個選項叫叫做enablezoombieObjects 取消選中
顯示隱藏文件
//顯示
defaultswritecom.apple.finderAppleShowAllFiles -bool true
killallFinder
//隱藏
defaultswritecom.apple.finderAppleShowAllFiles -bool false
killallFinder
字符串按多個符號分割
iOS跳轉到App Store下載應用評分
[[UIApplicationsharedApplication] openURL:[NSURLURLWithString:@"itms-apps://itunes.apple.com/WebObjects/MZStore.woa/wa/viewContentsUserReviews?type=Purple+Software&id=APPID"]];
iOS 獲取漢字的拼音
+ (NSString *)transform:(NSString *)chinese
{
//將NSString裝換成NSMutableString
NSMutableString *pinyin = [chinesemutableCopy];
//將漢字轉換為拼音(帶音標)
CFStringTransform((__bridgeCFMutableStringRef)pinyin, NULL, kCFStringTransformMandarinLatin, NO);
NSLog(@"%@", pinyin);
//去掉拼音的音標
CFStringTransform((__bridgeCFMutableStringRef)pinyin, NULL, kCFStringTransformStripCombiningMarks, NO);
NSLog(@"%@", pinyin);
//返回最近結果
return pinyin;
}
手動更改iOS狀態欄的顏色
- (void)setStatusBarBackgroundColor:(UIColor *)color
{
UIView *statusBar = [[[UIApplicationsharedApplication] valueForKey:@"statusBarWindow"] valueForKey:@"statusBar"];
if ([statusBarrespondsToSelector:@selector(setBackgroundColor:)])
{
statusBar.backgroundColor = color;
}
}
判斷當前ViewController是push還是present的方式顯示的
NSArray *viewcontrollers=self.navigationController.viewControllers;
if (viewcontrollers.count > 1)
{
if ([viewcontrollersobjectAtIndex:viewcontrollers.count - 1] == self)
{
//push方式
[self.navigationControllerpopViewControllerAnimated:YES];
}
}
else
{
//present方式
[self dismissViewControllerAnimated:YEScompletion:nil];
}
獲取實際使用的LaunchImage圖片
- (NSString *)getLaunchImageName
{
CGSizeviewSize = self.window.bounds.size;
// 豎屏
NSString *viewOrientation = @"Portrait";
NSString *launchImageName = nil;
NSArray* imagesDict = [[[NSBundlemainBundle] infoDictionary] valueForKey:@"UILaunchImages"];
for (NSDictionary* dictin imagesDict)
{
CGSizeimageSize = CGSizeFromString(dict[@"UILaunchImageSize"]);
if (CGSizeEqualToSize(imageSize, viewSize) && [viewOrientationisEqualToString:dict[@"UILaunchImageOrientation"]])
{
launchImageName = dict[@"UILaunchImageName"];
}
}
return launchImageName;
}
iOS在當前屏幕獲取第一響應
UIWindow * keyWindow = [[UIApplicationsharedApplication] keyWindow];
UIView * firstResponder = [keyWindowperformSelector:@selector(firstResponder)];
判斷對象是否遵循了某協議
if ([self.selectedControllerconformsToProtocol:@protocol(RefreshPtotocol)])
{
[self.selectedControllerperformSelector:@selector(onTriggerRefresh)];
}
判斷view是不是指定視圖的子視圖
BOOL isView = [textViewisDescendantOfView:self.view];
NSArray 快速求總和 最大值 最小值 和 平均值
NSArray *array = [NSArrayarrayWithObjects:@"2.0", @"2.3", @"3.0", @"4.0", @"10", nil];
CGFloatsum = [[array valueForKeyPath:@"@sum.floatValue"] floatValue];
CGFloatavg = [[array valueForKeyPath:@"@avg.floatValue"] floatValue];
CGFloatmax =[[array valueForKeyPath:@"@max.floatValue"] floatValue];
CGFloatmin =[[array valueForKeyPath:@"@min.floatValue"] floatValue];
NSLog(@"%f\n%f\n%f\n%f",sum,avg,max,min);
修改UITextField中Placeholder的文字顏色
[textFieldsetValue:[UIColorredColor] forKeyPath:@"_placeholderLabel.textColor"];
關于NSDateFormatter的格式
G: 公元時代，例如AD公元
yy: 年的后2位
yyyy: 完整年
MM: 月，顯示為1-12
MMM: 月，顯示為英文月份簡寫,如 Jan
MMMM: 月，顯示為英文月份全稱，如 Janualy
dd: 日，2位數表示，如02
d: 日，1-2位顯示，如 2
EEE: 簡寫星期幾，如Sun
EEEE: 全寫星期幾，如Sunday
aa: 上下午，AM/PM
H: 時，24小時制，0-23
K：時，12小時制，0-11
m: 分，1-2位
mm: 分，2位
s: 秒，1-2位
ss: 秒，2位
S: 毫秒
獲取一個類的所有子類
+ (NSArray *) allSubclasses
{
Class myClass = [self class];
NSMutableArray *mySubclasses = [NSMutableArrayarray];
unsigned int numOfClasses;
Class *classes = objc_copyClassList(&numOfClasses;);
for (unsigned int ci = 0; ci
監測IOS設備是否設置了代理，需要CFNetwork.framework
NSDictionary *proxySettings = (__bridgeNSDictionary *)(CFNetworkCopySystemProxySettings());
NSArray *proxies = (__bridgeNSArray *)(CFNetworkCopyProxiesForURL((__bridgeCFURLRef_Nonnull)([NSURLURLWithString:@"http://www.baidu.com"]), (__bridgeCFDictionaryRef_Nonnull)(proxySettings)));
NSLog(@"\n%@",proxies);
NSDictionary *settings = proxies[0];
NSLog(@"%@",[settingsobjectForKey:(NSString *)kCFProxyHostNameKey]);
NSLog(@"%@",[settingsobjectForKey:(NSString *)kCFProxyPortNumberKey]);
NSLog(@"%@",[settingsobjectForKey:(NSString *)kCFProxyTypeKey]);
if ([[settingsobjectForKey:(NSString *)kCFProxyTypeKey] isEqualToString:@"kCFProxyTypeNone"])
{
NSLog(@"沒代理");
}
else
{
NSLog(@"設置了代理");
}
阿拉伯數字轉中文格式
+(NSString *)translation:(NSString *)arebic
{
NSString *str = arebic;
NSArray *arabic_numerals = @[@"1",@"2",@"3",@"4",@"5",@"6",@"7",@"8",@"9",@"0"];
NSArray *chinese_numerals = @[@"一",@"二",@"三",@"四",@"五",@"六",@"七",@"八",@"九",@"零"];
NSArray *digits = @[@"個",@"十",@"百",@"千",@"萬",@"十",@"百",@"千",@"億",@"十",@"百",@"千",@"兆"];
NSDictionary *dictionary = [NSDictionarydictionaryWithObjects:chinese_numeralsforKeys:arabic_numerals];
NSMutableArray *sums = [NSMutableArrayarray];
for (int i = 0; i
Base64編碼與NSString對象或NSData對象的轉換
// Create NSData object
NSData *nsdata = [@"iOS Developer Tips encoded in Base64"
dataUsingEncoding:NSUTF8StringEncoding];
// Get NSString from NSData object in Base64
NSString *base64Encoded = [nsdatabase64EncodedStringWithOptions:0];
// Print the Base64 encoded string
NSLog(@"Encoded: %@", base64Encoded);
// Let's go the other way...
// NSData from the Base64 encoded str
NSData *nsdataFromBase64String = [[NSDataalloc]
initWithBase64EncodedString:base64Encodedoptions:0];
// Decoded NSString from the NSData
NSString *base64Decoded = [[NSStringalloc]
initWithData:nsdataFromBase64Stringencoding:NSUTF8StringEncoding];
NSLog(@"Decoded: %@", base64Decoded);
取消UICollectionView的隱式動畫
UICollectionView在reloadItems的時候，默認會附加一個隱式的fade動畫，有時候很討厭，尤其是當你的cell是復合cell的情況下(比如cell使用到了UIStackView)。
下面幾種方法都可以幫你去除這些動畫
//方法一
[UIViewperformWithoutAnimation:^{
[collectionViewreloadItemsAtIndexPaths:@[[NSIndexPathindexPathForItem:indexinSection:0]]];
}];
//方法二
[UIViewanimateWithDuration:0 animations:^{
[collectionViewperformBatchUpdates:^{
[collectionViewreloadItemsAtIndexPaths:@[[NSIndexPathindexPathForItem:indexinSection:0]]];
} completion:nil];
}];
//方法三
[UIViewsetAnimationsEnabled:NO];
[self.trackPanelperformBatchUpdates:^{
[collectionViewreloadItemsAtIndexPaths:@[[NSIndexPathindexPathForItem:indexinSection:0]]];
} completion:^(BOOL finished) {
[UIViewsetAnimationsEnabled:YES];
}];
讓Xcode的控制臺支持LLDB類型的打印
打開終端輸入三條命令:
touch ~/.lldbinit
echodisplay @importUIKit >> ~/.lldbinit
echotargetstop-hookadd -o \"targetstop-hookdisable\" >> ~/.lldbinit
CocoaPods pod install/pod update更新慢的問題
podinstall --verbose --no-repo-update
podupdate --verbose --no-repo-update
如果不加后面的參數，默認會升級CocoaPods的spec倉庫，加一個參數可以省略這一步，然后速度就會提升不少
UIImage 占用內存大小
UIImage *image = [UIImageimageNamed:@"aa"];
NSUIntegersize = CGImageGetHeight(image.CGImage) * CGImageGetBytesPerRow(image.CGImage);
GCD timer定時器
dispatch_queue_tqueue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
dispatch_source_ttimer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0,queue);
dispatch_source_set_timer(timer,dispatch_walltime(NULL, 0),1.0*NSEC_PER_SEC, 0); //每秒執行
dispatch_source_set_event_handler(timer, ^{
//@"倒計時結束，關閉"
dispatch_source_cancel(timer);
dispatch_async(dispatch_get_main_queue(), ^{
});
});
dispatch_resume(timer);
圖片上繪制文字 寫一個UIImage的category
- (UIImage *)imageWithTitle:(NSString *)titlefontSize:(CGFloat)fontSize
{
//畫布大小
CGSizesize=CGSizeMake(self.size.width,self.size.height);
//創建一個基于位圖的上下文
UIGraphicsBeginImageContextWithOptions(size,NO,0.0);//opaque:NO scale:0.0
[self drawAtPoint:CGPointMake(0.0,0.0)];
//文字居中顯示在畫布上
NSMutableParagraphStyle* paragraphStyle = [[NSParagraphStyledefaultParagraphStyle] mutableCopy];
paragraphStyle.lineBreakMode = NSLineBreakByCharWrapping;
paragraphStyle.alignment=NSTextAlignmentCenter;//文字居中
//計算文字所占的size,文字居中顯示在畫布上
CGSizesizeText=[titleboundingRectWithSize:self.sizeoptions:NSStringDrawingUsesLineFragmentOrigin
attributes:@{NSFontAttributeName:[UIFontsystemFontOfSize:fontSize]}context:nil].size;
CGFloatwidth = self.size.width;
CGFloatheight = self.size.height;
CGRectrect = CGRectMake((width-sizeText.width)/2, (height-sizeText.height)/2, sizeText.width, sizeText.height);
//繪制文字
[titledrawInRect:rectwithAttributes:@{ NSFontAttributeName:[UIFontsystemFontOfSize:fontSize],NSForegroundColorAttributeName:[ UIColorwhiteColor],NSParagraphStyleAttributeName:paragraphStyle}];
//返回繪制的新圖形
UIImage *newImage= UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
查找一個視圖的所有子視圖
- (NSMutableArray *)allSubViewsForView:(UIView *)view
{
NSMutableArray *array = [NSMutableArrayarrayWithCapacity:0];
for (UIView *subViewin view.subviews)
{
[array addObject:subView];
if (subView.subviews.count > 0)
{
[array addObjectsFromArray:[self allSubViewsForView:subView]];
}
}
return array;
}
計算文件大小
//文件大小
- (long long)fileSizeAtPath:(NSString *)path
{
NSFileManager *fileManager = [NSFileManagerdefaultManager];
if ([fileManagerfileExistsAtPath:path])
{
long long size = [fileManagerattributesOfItemAtPath:patherror:nil].fileSize;
return size;
}
return 0;
}
//文件夾大小
- (long long)folderSizeAtPath:(NSString *)path
{
NSFileManager *fileManager = [NSFileManagerdefaultManager];
long long folderSize = 0;
if ([fileManagerfileExistsAtPath:path])
{
NSArray *childerFiles = [fileManagersubpathsAtPath:path];
for (NSString *fileNamein childerFiles)
{
NSString *fileAbsolutePath = [pathstringByAppendingPathComponent:fileName];
if ([fileManagerfileExistsAtPath:fileAbsolutePath])
{
long long size = [fileManagerattributesOfItemAtPath:fileAbsolutePatherror:nil].fileSize;
folderSize += size;
}
}
}
return folderSize;
}
UIView設置部分圓角
你是不是也遇到過這樣的問題，一個button或者label，只要右邊的兩個角圓角，或者只要一個圓角。該怎么辦呢。這就需要圖層蒙版來幫助我們了
CGRectrect = view.bounds;
CGSizeradio = CGSizeMake(30, 30);//圓角尺寸
UIRectCornercorner = UIRectCornerTopLeft|UIRectCornerTopRight;//這只圓角位置
UIBezierPath *path = [UIBezierPathbezierPathWithRoundedRect:rectbyRoundingCorners:cornercornerRadii:radio];
CAShapeLayer *masklayer = [[CAShapeLayeralloc]init];//創建shapelayer
masklayer.frame = view.bounds;
masklayer.path = path.CGPath;//設置路徑
view.layer.mask = masklayer;
取上整與取下整
floor(x),有時候也寫做Floor(x)，其功能是“下取整”，即取不大于x的最大整數 例如：
x=3.14，floor(x)=3
y=9.99999，floor(y)=9
與floor函數對應的是ceil函數，即上取整函數。
ceil函數的作用是求不小于給定實數的最小整數。
ceil(2)=ceil(1.2)=cei(1.5)=2.00
floor函數與ceil函數的返回值均為double型
計算字符串字符長度，一個漢字算兩個字符
//方法一：
- (int)convertToInt:(NSString*)strtemp
{
int strlength = 0;
char* p = (char*)[strtempcStringUsingEncoding:NSUnicodeStringEncoding];
for (int i=0 ; i
給UIView設置圖片
UIImage *image = [UIImageimageNamed:@"image"];
self.MYView.layer.contents = (__bridgeid_Nullable)(image.CGImage);
self.MYView.layer.contentsRect = CGRectMake(0, 0, 0.5, 0.5);
防止scrollView手勢覆蓋側滑手勢
[scrollView.panGestureRecognizerrequireGestureRecognizerToFail:self.navigationController.interactivePopGestureRecognizer];
去掉導航欄返回的back標題
[[UIBarButtonItemappearance]setBackButtonTitlePositionAdjustment:UIOffsetMake(0, -60)forBarMetrics:UIBarMetricsDefault];
字符串中是否含有中文
+ (BOOL)checkIsChinese:(NSString *)string
{
for (int i=0; i
dispatch_group的使用
dispatch_group_tdispatchGroup = dispatch_group_create();
dispatch_group_enter(dispatchGroup);
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(1 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
NSLog(@"第一個請求完成");
dispatch_group_leave(dispatchGroup);
});
dispatch_group_enter(dispatchGroup);
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(10 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
NSLog(@"第二個請求完成");
dispatch_group_leave(dispatchGroup);
});
dispatch_group_notify(dispatchGroup, dispatch_get_main_queue(), ^(){
NSLog(@"請求完成");
});
UITextField每四位加一個空格,實現代理
- (BOOL)textField:(UITextField *)textFieldshouldChangeCharactersInRange:(NSRange)rangereplacementString:(NSString *)string
{
// 四位加一個空格
if ([string isEqualToString:@""])
{
// 刪除字符
if ((textField.text.length - 2) % 5 == 0)
{
textField.text = [textField.textsubstringToIndex:textField.text.length - 1];
}
return YES;
}
else
{
if (textField.text.length % 5 == 0)
{
textField.text = [NSStringstringWithFormat:@"%@ ", textField.text];
}
}
return YES;
}
獲取私有屬性和成員變量 #import
//獲取私有屬性 比如設置UIDatePicker的字體顏色
- (void)setTextColor
{
//獲取所有的屬性，去查看有沒有對應的屬性
unsigned int count = 0;
objc_property_t *propertys = class_copyPropertyList([UIDatePickerclass], &count);
for(int i = 0;i
//獲得成員變量 比如修改UIAlertAction的按鈕字體顏色
unsigned int count = 0;
Ivar *ivars = class_copyIvarList([UIAlertActionclass], &count);
for(int i =0;i
獲取手機安裝的應用
Class c =NSClassFromString(@"LSApplicationWorkspace");
id s = [(id)c performSelector:NSSelectorFromString(@"defaultWorkspace")];
NSArray *array = [s performSelector:NSSelectorFromString(@"allInstalledApplications")];
for (iditemin array)
{
NSLog(@"%@",[itemperformSelector:NSSelectorFromString(@"applicationIdentifier")]);
//NSLog(@"%@",[item performSelector:NSSelectorFromString(@"bundleIdentifier")]);
NSLog(@"%@",[itemperformSelector:NSSelectorFromString(@"bundleVersion")]);
NSLog(@"%@",[itemperformSelector:NSSelectorFromString(@"shortVersionString")]);
}
判斷兩個日期是否在同一周 寫在NSDate的category里面
- (BOOL)isSameDateWithDate:(NSDate *)date
{
//日期間隔大于七天之間返回NO
if (fabs([self timeIntervalSinceDate:date]) >= 7 * 24 *3600)
{
return NO;
}
NSCalendar *calender = [NSCalendarcurrentCalendar];
calender.firstWeekday = 2;//設置每周第一天從周一開始
//計算兩個日期分別為這年第幾周
NSUIntegercountSelf = [calenderordinalityOfUnit:NSCalendarUnitWeekdayinUnit:NSCalendarUnitYearforDate:self];
NSUIntegercountDate = [calenderordinalityOfUnit:NSCalendarUnitWeekdayinUnit:NSCalendarUnitYearforDate:date];
//相等就在同一周，不相等就不在同一周
return countSelf == countDate;
}
應用內打開系統設置界面
//iOS8之后
[[UIApplicationsharedApplication] openURL:[NSURLURLWithString:UIApplicationOpenSettingsURLString]];
//如果App沒有添加權限，顯示的是設定界面。如果App有添加權限（例如通知），顯示的是App的設定界面。
//iOS8之前
//先添加一個url type如下圖，在代碼中調用如下代碼,即可跳轉到設置頁面的對應項
[[UIApplicationsharedApplication] openURL:[NSURLURLWithString:@"prefs:root=WIFI"]];
可選值如下：
About — prefs:root=General&path=About
Accessibility — prefs:root=General&path=ACCESSIBILITY
AirplaneModeOn — prefs:root=AIRPLANE_MODE
Auto-Lock — prefs:root=General&path=AUTOLOCK
Brightness — prefs:root=Brightness
Bluetooth — prefs:root=General&path=Bluetooth
Date & Time — prefs:root=General&path=DATE_AND_TIME
FaceTime — prefs:root=FACETIME
General — prefs:root=General
Keyboard — prefs:root=General&path=Keyboard
iCloud — prefs:root=CASTLE
iCloudStorage & Backup — prefs:root=CASTLE&path=STORAGE_AND_BACKUP
International — prefs:root=General&path=INTERNATIONAL
LocationServices — prefs:root=LOCATION_SERVICES
Music — prefs:root=MUSIC
MusicEqualizer — prefs:root=MUSIC&path=EQ
MusicVolumeLimit — prefs:root=MUSIC&path=VolumeLimit
Network — prefs:root=General&path=Network
Nike + iPod — prefs:root=NIKE_PLUS_IPOD
Notes — prefs:root=NOTES
Notification — prefs:root=NOTIFICATI*****_ID
Phone — prefs:root=Phone
Photos — prefs:root=Photos
Profile — prefs:root=General&path=ManagedConfigurationList
Reset — prefs:root=General&path=Reset
Safari — prefs:root=Safari
Siri — prefs:root=General&path=Assistant
Sounds — prefs:root=Sounds
SoftwareUpdate — prefs:root=General&path=SOFTWARE_UPDATE_LINK
Store — prefs:root=STORE
推ter — prefs:root=推ter
Usage — prefs:root=General&path=USAGE
V*N — prefs:root=General&path=Network/V*N
Wallpaper — prefs:root=Wallpaper
Wi-Fi — prefs:root=WIFI
屏蔽觸發事件，2秒后取消屏蔽
[[UIApplicationsharedApplication] beginIgnoringInteractionEvents];
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(2 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
[[UIApplicationsharedApplication] endIgnoringInteractionEvents]
});
動畫暫停再開始
-(void)pauseLayer:(CALayer *)layer
{
CFTimeIntervalpausedTime = [layerconvertTime:CACurrentMediaTime() fromLayer:nil];
layer.speed = 0.0;
layer.timeOffset = pausedTime;
}
-(void)resumeLayer:(CALayer *)layer
{
CFTimeIntervalpausedTime = [layertimeOffset];
layer.speed = 1.0;
layer.timeOffset = 0.0;
layer.beginTime = 0.0;
CFTimeIntervaltimeSincePause = [layerconvertTime:CACurrentMediaTime() fromLayer:nil] - pausedTime;
layer.beginTime = timeSincePause;
}
fillRule原理
iOS中數字的格式化
//通過NSNumberFormatter，同樣可以設置NSNumber輸出的格式。例如如下代碼：
NSNumberFormatter *formatter = [[NSNumberFormatteralloc] init];
formatter.numberStyle = NSNumberFormatterDecimalStyle;
NSString *string = [formatterstringFromNumber:[NSNumbernumberWithInt:123456789]];
NSLog(@"Formatted number string:%@",string);
//輸出結果為：[1223:403] Formatted number string:123,456,789
//其中NSNumberFormatter類有個屬性numberStyle，它是一個枚舉型，設置不同的值可以輸出不同的數字格式。該枚舉包括：
typedef NS_ENUM(NSUInteger, NSNumberFormatterStyle) {
NSNumberFormatterNoStyle = kCFNumberFormatterNoStyle,
NSNumberFormatterDecimalStyle = kCFNumberFormatterDecimalStyle,
NSNumberFormatterCurrencyStyle = kCFNumberFormatterCurrencyStyle,
NSNumberFormatterPercentStyle = kCFNumberFormatterPercentStyle,
NSNumberFormatterScientificStyle = kCFNumberFormatterScientificStyle,
NSNumberFormatterSpellOutStyle = kCFNumberFormatterSpellOutStyle
};
//各個枚舉對應輸出數字格式的效果如下：其中第三項和最后一項的輸出會根據系統設置的語言區域的不同而不同。
[1243:403] Formattednumberstring:123456789
[1243:403] Formattednumberstring:123,456,789
[1243:403] Formattednumberstring:￥123,456,789.00
[1243:403] Formattednumberstring:-539,222,988%
[1243:403] Formattednumberstring:1.23456789E8
[1243:403] Formattednumberstring:一億二千三百四十五萬六千七百八十九
如何獲取WebView所有的圖片地址，
在網頁加載完成時，通過js獲取圖片和添加點擊的識別方式
//UIWebView
- (void)webViewDidFinishLoad:(UIWebView *)webView
{
//這里是js，主要目的實現對url的獲取
static NSString * const jsGetImages =
@"function getImages(){\
var objs = document.getElementsByTagName(\"img\");\
var imgScr = '';\
for(var i=0;i
//WKWebView
- (void)webView:(WKWebView *)webViewdidFinishNavigation:(null_unspecifiedWKNavigation *)navigation
{
static NSString * const jsGetImages =
@"function getImages(){\
var objs = document.getElementsByTagName(\"img\");\
var imgScr = '';\
for(var i=0;i
獲取到webview的高度
CGFloatheight = [[self.webViewstringByEvaluatingJavaScriptFromString:@"document.body.offsetHeight"] floatValue];
navigationBar變為純透明
//第一種方法
//導航欄純透明
[self.navigationBarsetBackgroundImage:[UIImagenew] forBarMetrics:UIBarMetricsDefault];
//去掉導航欄底部的黑線
self.navigationBar.shadowImage = [UIImagenew];
//第二種方法
[[self.navigationBarsubviews] objectAtIndex:0].alpha = 0;
tabBar同理
[self.tabBarsetBackgroundImage:[UIImagenew]];
self.tabBar.shadowImage = [UIImagenew];
navigationBar根據滑動距離的漸變色實現
//第一種
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
CGFloatoffsetToShow = 200.0;//滑動多少就完全顯示
CGFloatalpha = 1 - (offsetToShow - scrollView.contentOffset.y) / offsetToShow;
[[self.navigationController.navigationBarsubviews] objectAtIndex:0].alpha = alpha;
}
//第二種
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
CGFloatoffsetToShow = 200.0;
CGFloatalpha = 1 - (offsetToShow - scrollView.contentOffset.y) / offsetToShow;
[self.navigationController.navigationBarsetShadowImage:[UIImagenew]];
[self.navigationController.navigationBarsetBackgroundImage:[self imageWithColor:[[UIColororangeColor]colorWithAlphaComponent:alpha]] forBarMetrics:UIBarMetricsDefault];
}
//生成一張純色的圖片
- (UIImage *)imageWithColor:(UIColor *)color
{
CGRectrect = CGRectMake(0.0f, 0.0f, 1.0f, 1.0f);
UIGraphicsBeginImageContext(rect.size);
CGContextRefcontext = UIGraphicsGetCurrentContext();
CGContextSetFillColorWithColor(context, [colorCGColor]);
CGContextFillRect(context, rect);
UIImage *theImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return theImage;
}
iOS 開發中一些相關的路徑
模擬器的位置:
/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs
文檔安裝位置:
/Applications/Xcode.app/Contents/Developer/Documentation/DocSets
插件保存路徑:
~/Library/ApplicationSupport/Developer/Shared/Xcode/Plug-ins
自定義代碼段的保存路徑:
~/Library/Developer/Xcode/UserData/CodeSnippets/
如果找不到CodeSnippets文件夾，可以自己新建一個CodeSnippets文件夾。
描述文件路徑
~/Library/MobileDevice/ProvisioningProfiles
navigationItem的BarButtonItem如何緊靠屏幕右邊界或者左邊界？
一般情況下，右邊的item會和屏幕右側保持一段距離：
下面是通過添加一個負值寬度的固定間距的item來解決，也可以改變寬度實現不同的間隔：
UIImage *img = [[UIImageimageNamed:@"icon_cog"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
//寬度為負數的固定間距的系統item
UIBarButtonItem *rightNegativeSpacer = [[UIBarButtonItemalloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFixedSpacetarget:nilaction:nil];
[rightNegativeSpacersetWidth:-15];
UIBarButtonItem *rightBtnItem1 = [[UIBarButtonItemalloc]initWithImage:imgstyle:UIBarButtonItemStylePlaintarget:selfaction:@selector(rightButtonItemClicked:)];
UIBarButtonItem *rightBtnItem2 = [[UIBarButtonItemalloc]initWithImage:imgstyle:UIBarButtonItemStylePlaintarget:selfaction:@selector(rightButtonItemClicked:)];
self.navigationItem.rightBarButtonItems = @[rightNegativeSpacer,rightBtnItem1,rightBtnItem2];
NSString進行URL編碼和解碼
NSString *string = @"http://abc.com?aaa=你好&bbb=tttee";
//編碼 打印：http://abc.com?aaa=%E4%BD%A0%E5%A5%BD&bbb=tttee
string = [string stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSetURLQueryAllowedCharacterSet]];
//解碼 打印：http://abc.com?aaa=你好&bbb=tttee
string = [string stringByRemovingPercentEncoding];
UIWebView設置User-Agent。
//設置
NSDictionary *dic = @{@"UserAgent":@"your UserAgent"};
[[NSUserDefaultsstandardUserDefaults] registerDefaults:dic];
//獲取
NSString *agent = [self.WebViewstringByEvaluatingJavaScriptFromString:@"navigator.userAgent"];
獲取硬盤總容量與可用容量:
NSFileManager *fileManager = [NSFileManagerdefaultManager];
NSDictionary *attributes = [fileManagerattributesOfFileSystemForPath:NSHomeDirectory() error:nil];
NSLog(@"容量%.2fG",[attributes[NSFileSystemSize] doubleValue] / (powf(1024, 3)));
NSLog(@"可用%.2fG",[attributes[NSFileSystemFreeSize] doubleValue] / powf(1024, 3));
獲取UIColor的RGBA值
UIColor *color = [UIColorcolorWithRed:0.2 green:0.3 blue:0.9 alpha:1.0];
const CGFloat *components = CGColorGetComponents(color.CGColor);
NSLog(@"Red: %.1f", components[0]);
NSLog(@"Green: %.1f", components[1]);
NSLog(@"Blue: %.1f", components[2]);
NSLog(@"Alpha: %.1f", components[3]);
修改textField的placeholder的字體顏色、大小
[self.textFieldsetValue:[UIColorredColor] forKeyPath:@"_placeholderLabel.textColor"];
[self.textFieldsetValue:[UIFontboldSystemFontOfSize:16] forKeyPath:@"_placeholderLabel.font"];
AFN移除JSON中的NSNull
AFJSONResponseSerializer *response = [AFJSONResponseSerializerserializer];
response.removesKeysWithNullValues = YES;
ceil()和floor()
ceil() 功 能：返回大于或者等于指定表達式的最小整數
floor() 功 能：返回小于或者等于指定表達式的最大整數
UIWebView里面的圖片自適應屏幕
在webView加載完的代理方法里面這樣寫：
- (void)webViewDidFinishLoad:(UIWebView *)webView
{
NSString *js = @"function imgAutoFit() { \
var imgs = document.getElementsByTagName('img'); \
for (var i = 0; i
來自：http://ios.jobbole.com/91214/
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