iOS常用小功能（获得屏幕图像、压缩图片、加边框、调整label的size）

- (UIImage *)imageFromView: (UIView *) theView{  UIGraphicsBeginImageContext(theView.frame.size);  CGContextRef context = UIGraphicsGetCurrentContext();  [theView.layer renderInContext:context];  UIImage *theImage = UIGraphicsGetImageFromCurrentImageContext();  UIGraphicsEndImageContext();  return theImage;}

- (CGSize)labelAutoCalculateRectWith:(NSString*)text FontSize:(CGFloat)fontSize MaxSize:(CGSize)maxSize{  NSMutableParagraphStyle* paragraphStyle = [[NSMutableParagraphStyle alloc]init]; paragraphStyle.lineBreakMode=NSLineBreakByWordWrapping;  NSDictionary* attributes =@{NSFontAttributeName:[UIFont fontWithName:@"MicrosoftYaHei" size:fontSize],NSParagraphStyleAttributeName:paragraphStyle.copy};  CGSize labelSize = [text boundingRectWithSize:maxSize options:NSStringDrawingUsesLineFragmentOrigin|NSStringDrawingUsesFontLeading|NSStringDrawingTruncatesLastVisibleLine attributes:attributes context:nil].size;  labelSize.height=ceil(labelSize.height);  return labelSize;}

-(NSString*)TimeTrasformWithDate:(NSString *)dateString{  NSDateFormatter *formatter = [[NSDateFormatter alloc]init];  [formatter setDateFormat:@"YY-MM-dd HH:mm"];  [formatter setTimeZone:[NSTimeZone timeZoneWithName:@"Asia/Beijing"]];  NSString *date = [formatter stringFromDate:[NSDate dateWithTimeIntervalSince1970:dateString.integerValue]];  //NSLog(@"date1:%@",date);  return date;}

+ (UIColor *)colorFromHexRGB:(NSString *)inColorString{  UIColor *result = nil;  unsigned int colorCode = 0;  unsigned char redByte, greenByte, blueByte;  if (nil != inColorString)  {    NSScanner *scanner = [NSScanner scannerWithString:inColorString];    (void) [scanner scanHexInt:&colorCode]; // ignore error  }  redByte = (unsigned char) (colorCode >> 16);  greenByte = (unsigned char) (colorCode >> 8);  blueByte = (unsigned char) (colorCode); // masks off high bits  result = [UIColor       colorWithRed: (float)redByte / 0xff       green: (float)greenByte/ 0xff       blue: (float)blueByte / 0xff       alpha:1.0];  return result;}

UIRectCorner corners=UIRectCornerTopLeft | UIRectCornerTopRight;  UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:view.bounds        byRoundingCorners:corners cornerRadii:CGSizeMake(4, 0)];CAShapeLayer *maskLayer = [CAShapeLayer layer];maskLayer.frame     = view.bounds;maskLayer.path     = maskPath.CGPath;view.layer.mask     = maskLayer;

+ (UIImage*)imageWithImageSimple:(UIImage*)image scaledToSize:(CGSize)newSize{  //创建一个图形上下文形象  UIGraphicsBeginImageContext(newSize);  // 告诉旧图片画在这个新的环境,所需的  // new size  [image drawInRect:CGRectMake(0,0,newSize.width,newSize.height)];  //获取上下文的新形象  UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();  // 结束上下文  UIGraphicsEndImageContext();  return newImage;}

[textF setValue:[UIColor whiteColor] forKeyPath:@"_placeholderLabel.textColor"];[textF setValue:[UIFont boldSystemFontOfSize:15] forKeyPath:@"_placeholderLabel.font"];

butLeft. imageEdgeInsets = UIEdgeInsetsMake (7 , 5 , 7 , 25 );butLeft.contentHorizontalAlignment = UIControlContentHorizontalAlignmentCenter;

- (void)label:(UILabel *)label BehindTextSize:(NSInteger)integer{  NSMutableAttributedString *mutaString = [[NSMutableAttributedString alloc] initWithString:label.text];  [mutaString addAttribute:NSFontAttributeName value:[UIFont boldSystemFontOfSize:16] range:NSMakeRange(label.text.length-2, 2)];  label.attributedText = mutaString;}

- (void)ChangeLabelTextColor:(UILabel *)label{  NSMutableAttributedString *mutaString = [[NSMutableAttributedString alloc] initWithString:label.text];  [mutaString addAttribute:NSForegroundColorAttributeName value:[UIColor colorWithRed:207/255.0 green:34/255.0 blue:42/255.0 alpha:1] range:NSMakeRange(0, 5)];  label.attributedText = mutaString;}

if ([tableView respondsToSelector:@selector(setSeparatorInset:)]) {    [tableView setSeparatorInset:UIEdgeInsetsZero];  }  if ([[UIDevice currentDevice].systemVersion floatValue] >= 8.0) {    if ([tableView respondsToSelector:@selector(setLayoutMargins:)]) {    [tableView setLayoutMargins:UIEdgeInsetsZero];  }  }  // Do any additional setup after loading the view.}- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath{  if ([cell respondsToSelector:@selector(setSeparatorInset:)]) {    [cell setSeparatorInset:UIEdgeInsetsZero];  }  if ([[UIDevice currentDevice].systemVersion floatValue] >= 8.0) {    if ([cell respondsToSelector:@selector(setLayoutMargins:)]) {    [cell setLayoutMargins:UIEdgeInsetsZero];  }  }  }

-(UIImage *) grayscaleImage: (UIImage *) image{  CGSize size = image.size;  CGRect rect = CGRectMake(0.0f, 0.0f, image.size.width,               image.size.height);  // Create a mono/gray color space  CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceGray();  CGContextRef context = CGBitmapContextCreate(nil, size.width,                         size.height, 8, 0, colorSpace, kCGImageAlphaNone);  CGColorSpaceRelease(colorSpace);  // Draw the image into the grayscale context  CGContextDrawImage(context, rect, [image CGImage]);  CGImageRef grayscale = CGBitmapContextCreateImage(context);  CGContextRelease(context);  // Recover the image  UIImage *img = [UIImage imageWithCGImage:grayscale];  CFRelease(grayscale);  return img;}

#define UIColorFromRGB(rgbValue) [UIColor colorWithRed:((float)((rgbValue & 0xFF0000) >> 16))/255.0 green:((float)((rgbValue & 0xFF00) >> 8))/255.0 blue:((float)(rgbValue & 0xFF))/255.0 alpha:1.0]