UIFont设置

+ (UIFont *)preferredFontForTextStyle:(NSString *)style

style:

UIKIT_EXTERNNSString *const UIFontTextStyleHeadlineNS_AVAILABLE_IOS(7_0);
UIKIT_EXTERNNSString *const UIFontTextStyleBodyNS_AVAILABLE_IOS(7_0);
UIKIT_EXTERNNSString *const UIFontTextStyleSubheadlineNS_AVAILABLE_IOS(7_0);
UIKIT_EXTERNNSString *const UIFontTextStyleFootnoteNS_AVAILABLE_IOS(7_0);
UIKIT_EXTERNNSString *const UIFontTextStyleCaption1NS_AVAILABLE_IOS(7_0);
UIKIT_EXTERNNSString *const UIFontTextStyleCaption2NS_AVAILABLE_IOS(7_0);

+ (UIFont *)fontWithName:(NSString *)fontName size:(CGFloat)fontSize;

fontName:
NSArray *fontFamilies = [UIFontfamilyNames];
NSLog(@"%@",fontFamilies);

根据Rect设置Font size

int currentFontSize = 17.0;
CGSize requiredSize = [str boundingRectWithSize:maxSize
options:NSStringDrawingUsesFontLeading
attributes:@{NSFontAttributeName : [UIFont systemFontOfSize:currentFontSize]}
context:nil].size;
if(requiredSize.height <= maxSize.height){
while (requiredSize.height <= maxSize.height && requiredSize.width <= maxSize.width) {
currentFontSize ++;
requiredSize = [str boundingRectWithSize:maxSize
options:NSStringDrawingUsesFontLeading
attributes:@{NSFontAttributeName:[UIFont systemFontOfSize:currentFontSize]}
context:nil].size;
}
}else{
while (requiredSize.height > maxSize.height || requiredSize.width > maxSize.height) {
currentFontSize --;
requiredSize = [str boundingRectWithSize:maxSize
options:NSStringDrawingUsesFontLeading
attributes:@{NSFontAttributeName:[UIFont systemFontOfSize:currentFontSize]}
context:nil].size;

}
requiredSize = [str boundingRectWithSize:maxSize
options:NSStringDrawingUsesFontLeading
attributes:@{NSFontAttributeName:[UIFont systemFontOfSize:currentFontSize]}
context:nil].size;
}