tableView上面多出來20個像素，是因為自動布局的緣故，設(shè)置一下屬性就可以解決問題

self.edgesForExtendedLayout = UIRectEdgeNone;

如果想數(shù)組進行倒序排列

NSMutableArray *array = [NSMutableArray arrayWithObjects:@“1”,@“2”,@“3”,nil];

NSArray *reversedArray = [[array reverseObjectEnumerator allObjects];

如果想scrollView不能上下滑動只能左右滑動下面設(shè)置可以實現(xiàn)

- (void)scrollViewDidScroll:(UIScrollView *)scrollView{

Float oldY = 0.0;

[scrollView setContentOffset:CGPointMake(scrollView.contentOffset.x,oldY)];

}

設(shè)置UILabel行間距和字間距

+(void)setLabelSpace:(UILabel*)label withValue:(NSString*)str withFont:(UIFont*)font{

NSMutableParagraphStyle*paraStyle = [[NSMutableParagraphStylealloc]init];

paraStyle.lineBreakMode=NSLineBreakByCharWrapping;

paraStyle.alignment=NSTextAlignmentLeft;

paraStyle.lineSpacing=UILABEL_LINE_SPACE;//設(shè)置行間距

paraStyle.hyphenationFactor=1.0;

paraStyle.firstLineHeadIndent=0.0;

paraStyle.paragraphSpacingBefore=0.0;

paraStyle.headIndent=0;

paraStyle.tailIndent=0;

//設(shè)置字間距NSKernAttributeName:@1.5f

NSDictionary*dic =@{NSFontAttributeName:font,NSParagraphStyleAttributeName:paraStyle,NSKernAttributeName:@0.0f};

NSAttributedString*attributeStr = [[NSAttributedStringalloc]initWithString:strattributes:dic];

label.attributedText= attributeStr;

}

5、計算UILabel的高度(帶有行間距的情況)

+(CGFloat)getSpaceLabelHeight:(NSString*)str withFont:(UIFont*)font withWidth:(CGFloat)width {

NSMutableParagraphStyle*paraStyle = [[NSMutableParagraphStylealloc]init];

paraStyle.lineBreakMode=NSLineBreakByCharWrapping;

paraStyle.alignment=NSTextAlignmentLeft;

paraStyle.lineSpacing=UILABEL_LINE_SPACE;

paraStyle.hyphenationFactor=1.0;

paraStyle.firstLineHeadIndent=0.0;

paraStyle.paragraphSpacingBefore=0.0;

paraStyle.headIndent=0;

paraStyle.tailIndent=0;

NSDictionary*dic =@{NSFontAttributeName:font,NSParagraphStyleAttributeName:paraStyle,NSKernAttributeName:@0.0f};

CGSizesize = [strboundingRectWithSize:CGSizeMake(width,KHeight)options:NSStringDrawingUsesLineFragmentOriginattributes:diccontext:nil].size;

returnsize.height;

}