【IOS】IOS開發總結,持續更新...
阿新 • • 發佈：2019-02-07
- 給一個view截圖
UIGraphicsBeginImageContextWithOptions(view.bounds.size, YES, 0.0);
[view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
2. collectionView的內容小於其寬高的時候是不能滾動的，設定可以滾動：
collectionView.alwaysBounceHorizontal = YES;
collectionView.alwaysBounceVertical = YES;
3. 設定navigationBar上的title顏色和大小
[self.navigationController.navigationBar setTitleTextAttributes:@{NSForegroundColorAttributeName : [UIColor youColor], NSFontAttributeName : [UIFont systemFontOfSize:15]}]
4. 顏色轉圖片
(CGFloat)getCachSize {
NSUInteger imageCacheSize = [[SDImageCache sharedImageCache] getSize]; //獲取自定義快取大小 //用列舉器遍歷 一個資料夾的內容 //1.獲取 資料夾列舉器 NSString *myCachePath = [NSHomeDirectory() stringByAppendingPathComponent:@"Library/Caches"]; NSDirectoryEnumerator *enumerator = [[NSFileManager defaultManager] enumeratorAtPath:myCachePath]; __block NSUInteger count = 0; //2.遍歷 for (NSString *fileName in enumerator) { NSString *path = [myCachePath stringByAppendingPathComponent:fileName]; NSDictionary *fileDict = [[NSFileManager defaultManager] attributesOfItemAtPath:path error:nil]; count += fileDict.fileSize;//自定義所有快取大小 } // 得到是位元組 轉化為M CGFloat totalSize = ((CGFloat)imageCacheSize+count)/1024/1024; return totalSize;
}
5. 獲取APP快取大小
(CGFloat)getCachSize {
NSUInteger imageCacheSize = [[SDImageCache sharedImageCache] getSize]; //獲取自定義快取大小 //用列舉器遍歷 一個資料夾的內容 //1.獲取 資料夾列舉器 NSString *myCachePath = [NSHomeDirectory() stringByAppendingPathComponent:@"Library/Caches"]; NSDirectoryEnumerator *enumerator = [[NSFileManager defaultManager] enumeratorAtPath:myCachePath]; __block NSUInteger count = 0; //2.遍歷 for (NSString *fileName in enumerator) { NSString *path = [myCachePath stringByAppendingPathComponent:fileName]; NSDictionary *fileDict = [[NSFileManager defaultManager] attributesOfItemAtPath:path error:nil]; count += fileDict.fileSize;//自定義所有快取大小 } // 得到是位元組 轉化為M CGFloat totalSize = ((CGFloat)imageCacheSize+count)/1024/1024; return totalSize;
}
6. 清理APP快取
- (void)handleClearView {
//刪除兩部分
//1.刪除 sd 圖片快取
//先清除記憶體中的圖片快取
[[SDImageCache sharedImageCache] clearMemory];
//清除磁碟的快取
[[SDImageCache sharedImageCache] clearDisk];
//2.刪除自己快取
NSString *myCachePath = [NSHomeDirectory() stringByAppendingPathComponent:@"Library/Caches"];
[[NSFileManager defaultManager] removeItemAtPath:myCachePath error:nil];
}```
- 身份證號驗證
- (BOOL)validateIdentityCard {
BOOL flag;
if (self.length <= 0) {
flag = NO;
return flag;
}
NSString *regex2 = @"^(\\d{14}|\\d{17})(\\d|[xX])$";
NSPredicate *identityCardPredicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@",regex2];
return [identityCardPredicate evaluateWithObject:self];
}
- UITextView實現placeHolder佔位文字
通過runtime，我們發現，UITextView內部有一個名為“_placeHolderLabel”的私有成員變數。大家知道，Objective-C沒有絕對的私有變數，因為我們可以通過KVC來訪問私有變數。
特點：雖然Apple官方沒有給我們開發者提供類似於placeholder的屬性，但是通過執行時，我們遍歷出了一個placeHolderLabel的私有變數。這種方法簡單易懂，程式碼量少，推薦大家使用這種方法。
UILabel *label =[JDUtils createLabelWithFrame:CGRectZero Font:18 Text:@"請輸入備註"];
[label sizeToFit];
label.textColor = [UIColor lightGrayColor];
[_textView addSubview:label];
[_textView setValue:label forKey:@"_placeholderLabel"];
[self.view addSubview:_textView];
- 刪除NSUserDefaults所有記錄
//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];
}
// 方法三
[[NSUserDefaults standardUserDefaults] setPersistentDomain:[NSDictionary dictionary] forName:[[NSBundle mainBundle] bundleIdentifier]];
- 自定義cell選中背景顏色
UIView *bgColorView = [[UIView alloc] init];
bgColorView.backgroundColor = [UIColor redColor];
[cell setSelectedBackgroundView:bgColorView];```
- UIView背景顏色漸變
UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 100)];
[self.view addSubview:view];
CAGradientLayer *gradient = [CAGradientLayer layer];
gradient.frame = view.bounds;
gradient.colors = [NSArray arrayWithObjects:(id)[[UIColor blackColor] CGColor], (id)[[UIColor whiteColor] CGColor], nil];
[view.layer insertSublayer:gradient atIndex:0];```
- 在非ViewController的地方彈出UIAlertController對話方塊
// 最好抽成一個分類
UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"Title" message:@"message" preferredStyle:UIAlertControllerStyleAlert];
//...
id rootViewController = [UIApplication sharedApplication].delegate.window.rootViewController;
if([rootViewController isKindOfClass:[UINavigationController class]])
{
rootViewController = ((UINavigationController *)rootViewController).viewControllers.firstObject;
}
if([rootViewController isKindOfClass:[UITabBarController class]])
{
rootViewController = ((UITabBarController *)rootViewController).selectedViewController;
}
[rootViewController presentViewController:alertController animated:YES completion:nil];```
- 獲取一個view所屬的控制器
// view分類方法
- (UIViewController *)belongViewController {
for (UIView next = [self superview]; next; next = next.superview) {
UIResponder nextResponder = [next nextResponder];
if ([nextResponder isKindOfClass:[UIViewController class]]) {
return (UIViewController *)nextResponder;
}
}
return nil;
}
- UIImage和base64互轉
// view分類方法
(NSString *)encodeToBase64String:(UIImage *)image {
return [UIImagePNGRepresentation(image) base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
}(UIImage *)decodeBase64ToImage:(NSString *)strEncodeData {
NSData *data = [[NSData alloc]initWithBase64EncodedString:strEncodeData options:NSDataBase64DecodingIgnoreUnknownCharacters];
return [UIImage imageWithData:data];
}```-
讓推送只有聲音沒有橫幅的方法
把本地推送的alertBody設定為空字串
-
去掉icon上的角標數字
[[UIApplication sharedApplication] setApplicationIconBadgeNumber:0];