iOS开发——实用性技巧
分享一些项目中常用的方法,可以保存起来,作为自己的工具集哦。
+ (CGFloat)diskOfAllSizeMBytes { CGFloat size = 0.0; NSError *error; NSDictionary *dic = [[NSFileManager defaultManager] attributesOfFileSystemForPath:NSHomeDirectory() error:&error]; if (error) { #ifdef DEBUG NSLog(@"error: %@", error.localizedDescription); #endif }else{ NSNumber *number = [dic objectForKey:NSFileSystemSize]; size = [number floatValue]/1024/1024; } return size; }
+ (CGFloat)diskOfFreeSizeMBytes { CGFloat size = 0.0; NSError *error; NSDictionary *dic = [[NSFileManager defaultManager] attributesOfFileSystemForPath:NSHomeDirectory() error:&error]; if (error) { #ifdef DEBUG NSLog(@"error: %@", error.localizedDescription); #endif }else{ NSNumber *number = [dic objectForKey:NSFileSystemFreeSize]; size = [number floatValue]/1024/1024; } return size; }
+ (NSDictionary *)dictionaryOrderByCharacterWithOriginalArray:(NSArray *)array { if (array.count == 0) { return nil; } for (id obj in array) { if (![obj isKindOfClass:[NSString class]]) { return nil; } } UILocalizedIndexedCollation *indexedCollation = [UILocalizedIndexedCollation currentCollation]; NSMutableArray *objects = [NSMutableArray arrayWithCapacity:indexedCollation.sectionTitles.count]; //创建27个分组数组 for (int i = 0; i < indexedCollation.sectionTitles.count; i++) { NSMutableArray *obj = [NSMutableArray array]; [objects addObject:obj]; } NSMutableArray *keys = [NSMutableArray arrayWithCapacity:objects.count]; //按字母顺序进行分组 NSInteger lastIndex = -1; for (int i = 0; i < array.count; i++) { NSInteger index = [indexedCollation sectionForObject:array[i] collationStringSelector:@selector(uppercaseString)]; [[objects objectAtIndex:index] addObject:array[i]]; lastIndex = index; } //去掉空数组 for (int i = 0; i < objects.count; i++) { NSMutableArray *obj = objects[i]; if (obj.count == 0) { [objects removeObject:obj]; } } //获取索引字母 for (NSMutableArray *obj in objects) { NSString *str = obj[0]; NSString *key = [self firstCharacterWithString:str]; [keys addObject:key]; } NSMutableDictionary *dic = [NSMutableDictionary dictionary]; [dic setObject:objects forKey:keys]; return dic; }
+ (NSDictionary *)dictionaryOrderByCharacterWithOriginalArray:(NSArray *)array { if (array.count == 0) { return nil; } for (id obj in array) { if (![obj isKindOfClass:[NSString class]]) { return nil; } } UILocalizedIndexedCollation *indexedCollation = [UILocalizedIndexedCollation currentCollation]; NSMutableArray *objects = [NSMutableArray arrayWithCapacity:indexedCollation.sectionTitles.count]; //创建27个分组数组 for (int i = 0; i < indexedCollation.sectionTitles.count; i++) { NSMutableArray *obj = [NSMutableArray array]; [objects addObject:obj]; } NSMutableArray *keys = [NSMutableArray arrayWithCapacity:objects.count]; //按字母顺序进行分组 NSInteger lastIndex = -1; for (int i = 0; i < array.count; i++) { NSInteger index = [indexedCollation sectionForObject:array[i] collationStringSelector:@selector(uppercaseString)]; [[objects objectAtIndex:index] addObject:array[i]]; lastIndex = index; } //去掉空数组 for (int i = 0; i < objects.count; i++) { NSMutableArray *obj = objects[i]; if (obj.count == 0) { [objects removeObject:obj]; } } //获取索引字母 for (NSMutableArray *obj in objects) { NSString *str = obj[0]; NSString *key = [self firstCharacterWithString:str]; [keys addObject:key]; } NSMutableDictionary *dic = [NSMutableDictionary dictionary]; [dic setObject:objects forKey:keys]; return dic; }
// 怀旧 --> CIPhotoEffectInstant 单色 --> CIPhotoEffectMono // 黑白 --> CIPhotoEffectNoir 褪色 --> CIPhotoEffectFade // 色调 --> CIPhotoEffectTonal 冲印 --> CIPhotoEffectProcess // 岁月 --> CIPhotoEffectTransfer 铬黄 --> CIPhotoEffectChrome // CILinearToSRGBToneCurve, CISRGBToneCurveToLinear, CIGaussianBlur, CIBoxBlur, CIDiscBlur, CISepiaTone, CIDepthOfField + (UIImage *)filterWithOriginalImage:(UIImage *)image filterName:(NSString *)name { CIContext *context = [CIContext contextWithOptions:nil]; CIImage *inputImage = [[CIImage alloc] initWithImage:image]; CIFilter *filter = [CIFilter filterWithName:name]; [filter setValue:inputImage forKey:kCIInputImageKey]; CIImage *result = [filter valueForKey:kCIOutputImageKey]; CGImageRef cgImage = [context createCGImage:result fromRect:[result extent]]; UIImage *resultImage = [UIImage imageWithCGImage:cgImage]; CGImageRelease(cgImage); return resultImage; }
// CIGaussianBlur ---> 高斯模糊 // CIBoxBlur ---> 均值模糊(Available in iOS 9.0 and later) // CIDiscBlur ---> 环形卷积模糊(Available in iOS 9.0 and later) // CIMedianFilter ---> 中值模糊, 用于消除图像噪点, 无需设置radius(Available in iOS 9.0 and later) // CIMotionBlur ---> 运动模糊, 用于模拟相机移动拍摄时的扫尾效果(Available in iOS 9.0 and later) + (UIImage *)blurWithOriginalImage:(UIImage *)image blurName:(NSString *)name radius:(NSInteger)radius { CIContext *context = [CIContext contextWithOptions:nil]; CIImage *inputImage = [[CIImage alloc] initWithImage:image]; CIFilter *filter; if (name.length != 0) { filter = [CIFilter filterWithName:name]; [filter setValue:inputImage forKey:kCIInputImageKey]; if (![name isEqualToString:@"CIMedianFilter"]) { [filter setValue:@(radius) forKey:@"inputRadius"]; } CIImage *result = [filter valueForKey:kCIOutputImageKey]; CGImageRef cgImage = [context createCGImage:result fromRect:[result extent]]; UIImage *resultImage = [UIImage imageWithCGImage:cgImage]; CGImageRelease(cgImage); return resultImage; }else{ return nil; } }
//Avilable in iOS 8.0 and later + (UIVisualEffectView *)effectViewWithFrame:(CGRect)frame { UIBlurEffect *effect = [UIBlurEffect effectWithStyle:UIBlurEffectStyleLight]; UIVisualEffectView *effectView = [[UIVisualEffectView alloc] initWithEffect:effect]; effectView.frame = frame; return effectView; }
+ (void)setLineSpaceWithString:(UILabel *)label { NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithString:label.text]; NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init]; [paragraphStyle setLineSpacing:3]; //调整行间距 [attributedString addAttribute:NSParagraphStyleAttributeName value:paragraphStyle range:NSMakeRange(0, [label.text length])]; label.attributedText = attributedString; }
- (void)scrollViewDidScroll:(UIScrollView *)scrollView { if(scrollView == self.myTab) { CGFloat sectionHeaderHeight = 40; 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); } } }优质内容筛选与推荐>>