項目中的要求總是多種多樣的.最近公司項目有新的要求.舉個例子來說,UIlabel在5s上的字體是16號,正常情況下在6p上面也是16號.但這樣看起來在6p上面就顯的字體太小.于是需求也應運而生,就是字體在6p上也要有一定的放大,放大比例就是是屏幕寬度的放大比例.
這樣也很簡單,就是在初始化的時候,只需要讓label的font乘以一個比例值就行了,但項目已經成形,之前的label辣么多一個一個改起來也是相當的費勁.
思考之下.做了一個方案.就是創建label的類別,在其中用runtime方法實現setFont方法的交換,在自己的方法中在進行設置比例的設定.這樣,之前寫過的也就不用改了.
再者,就是計算高度,用frame初始化的Label,左右間距都是數字,這樣很容易計算.但,現在項目中估計大多數都是XIB或者用Masonry做的約束吧.這樣以來,如果左右間距的約束也有相應比例值的計算.臨時用臨時計算也是個麻煩事.現在,我在label的類別中實現了這樣的計算方法,就是用frame初始化的label有獲取高度的方法,包括行間距的設定.用約束設置的label,只需要把label的父視圖和內容contentStr傳進方法中,也能同樣計算出高度.
代碼技術含量也不高.但想用的話也不用大家在自己寫了.copy過去就OK了.
==========================代碼分割線==============================
.h類中的代碼
#import@interface UILabel (XbnFontScale)
/**
*? @author Zn, 16-07-08 13:07:21
*
*? 返回帶有自定義行間距高度的label內容高度
*
*? @param str? ? ? 內容
*? @param width? ? 基準寬度
*? @param lineSpace 自定義的行高
*
*? @return
*/
- (CGFloat)returnTheLabelContentHeightWithContentStr:(NSString *)str baseWidth:(CGFloat)width baseCustomLineSpace:(CGFloat)lineSpace;
/**
*? @author , 16-07-08 13:07:00
*
*? 返回label內容高度
*
*? @param str? 內容
*? @param width 基準寬度
*
*? @return
*/
- (CGFloat)returnTheLabelContentHeightWithContentStr:(NSString *)str baseWidth:(CGFloat)width;
/**
*? @author , 16-07-08 16:07:32
*
*? 如果label不是用frame初始化,而是用約束設置的左右間距,那這個時候用這個方法來返回內容高度
*? 左右約束必須都有,不然也沒有意義
*? @param str? ? ? 內容
*? @param lineSpace 行間距,沒有傳0
*? @param superView label的父視圖
*
*? @return 內容高度
*/
- (CGFloat)returnTheConstraintsLabelContentHeightWithContentStr:(NSString *)str baseCustomLineSpace:(CGFloat)lineSpace accordingToLabelSuperView:(UIView *)superView;
@end
.m中代碼
#import "UILabel+XbnFontScale.h"
#import <objc/runtime.h>
#define? W [UIScreen mainScreen].bounds.size.width
#define? H [UIScreen mainScreen].bounds.size.height
#define? wScale W/320
#define? hScale H/568
@implementation UILabel (XbnFontScale)
/**
*? @author Zn, 16-07-08 09:07:47
*
*? 交換setFont? 方法,在新方法中進行適配.代碼中依然調用.font方法即可
*/
+ (void)load
{
Class class = [self class];
SEL originalSelector = @selector(setFont:);
SEL swizzledSelector = @selector(setFontScale:);
Method originalMethod = class_getInstanceMethod(class, originalSelector);
Method swizzledMethod = class_getInstanceMethod(class, swizzledSelector);
BOOL didAddMethod =class_addMethod(class,
originalSelector,
method_getImplementation(swizzledMethod),
method_getTypeEncoding(swizzledMethod));
if (didAddMethod) {
class_replaceMethod(class,
swizzledSelector,
method_getImplementation(originalMethod),
method_getTypeEncoding(originalMethod));
} else {
method_exchangeImplementations(originalMethod, swizzledMethod);
}
}
- (void)setFontScale:(UIFont *)font {
CGFloat s = font.pointSize*wScale;
UIFont *scaleFont = [UIFont systemFontOfSize:s];
[self setFontScale:scaleFont];
}
/**
*? @author Zn, 16-07-08 14:07:45
*
*? 返回有自定義行間距的label高度
*
*
*/
- (CGFloat)returnTheLabelContentHeightWithContentStr:(NSString *)str baseWidth:(CGFloat)width baseCustomLineSpace:(CGFloat)lineSpace
{
NSMutableParagraphStyle *paraStyle = [[NSMutableParagraphStyle alloc] init];
paraStyle.lineBreakMode = NSLineBreakByCharWrapping;
paraStyle.lineSpacing = lineSpace; //行高
paraStyle.hyphenationFactor = 0.0;
paraStyle.firstLineHeadIndent = 0.0;//第一行縮進
paraStyle.paragraphSpacingBefore = 0.0;//段落間距
paraStyle.headIndent = 0.0;//頭縮進
paraStyle.tailIndent = 0.0;//尾縮進
//NSKernAttributeName 會影響高度的計算.并且是四舍五入的.0.4就是0.? 0.5就是1.具體作用需要再測
NSDictionary *dic = @{NSFontAttributeName:self.font,NSParagraphStyleAttributeName:paraStyle,NSKernAttributeName:@0.0f};
CGSize s = [str boundingRectWithSize:CGSizeMake(width, CGFLOAT_MAX) options:NSStringDrawingUsesLineFragmentOrigin attributes:dic context:nil].size;
return s.height;
}
/**
*? @author Zn, 16-07-08 14:07:08
*
*? 返回默認行間距的label高度
*
*
*/
- (CGFloat)returnTheLabelContentHeightWithContentStr:(NSString *)str baseWidth:(CGFloat)width
{
CGSize s = [str boundingRectWithSize:CGSizeMake(width, CGFLOAT_MAX) options:NSStringDrawingUsesLineFragmentOrigin attributes:@{NSFontAttributeName : self.font,NSKernAttributeName:@0.0f} context:nil].size;
return s.height;
}
/**
*? @author Zn, 16-07-08 16:07:32
*
*? 如果label不是用frame初始化,而是用約束設置的左右間距,那這個時候用這個方法來返回內容高度
*? 左右約束必須都有,不然也沒有意義
*
*/
- (CGFloat)returnTheConstraintsLabelContentHeightWithContentStr:(NSString *)str baseCustomLineSpace:(CGFloat)lineSpace accordingToLabelSuperView:(UIView *)superView
{
CGFloat height = 0.0;
if (str.length <= 0) {
return height;
}
NSArray *constrainsArr = superView.constraints;//獲取約束集
if (constrainsArr.count == 0) {
return height;
}
CGFloat leftSpace = 0.0;
CGFloat rightSpace = 0.0;
for (NSLayoutConstraint *constraint in constrainsArr) {//masonry也是繼承自NSLayoutConstraint
/*
舉例解釋:A B兩個視圖,B 是A的子視圖. [A addSubView: B];
B 設置的top,leading, bottom, trailing四個約束,無論在何種情況下:
top 與 leading 的約束的firstItem都是子視圖B,secondItem 是父視圖A
bottom 與 trailing 的約束的firstItem都是父視圖A, secondItem是子視圖B
*/
//這里獲取本 label
UILabel *labelFirst = (UILabel *)constraint.firstItem;
UILabel *lableSecond = (UILabel *)constraint.secondItem;
if (labelFirst == self || lableSecond == self) {
if (constraint.firstAttribute == NSLayoutAttributeLeading || constraint.firstAttribute == NSLayoutAttributeLeft) {//獲取到label的左側約束
leftSpace = constraint.constant;
NSLog(@"================%lf",leftSpace);
}
if (constraint.secondAttribute == NSLayoutAttributeTrailing || constraint.secondAttribute == NSLayoutAttributeRight) {//獲取到label的右側約束
rightSpace = -constraint.constant;
NSLog(@"------------------===%lf",rightSpace);
}
}
}
//最終拿到了label的基準寬度,往下計算高度就簡單了
CGFloat baseWidth = W - leftSpace - rightSpace;
//調用方法計算高度
if (lineSpace <= 0.0) {
height = [self returnTheLabelContentHeightWithContentStr:str baseWidth:baseWidth];
}else{
height = [self returnTheLabelContentHeightWithContentStr:str baseWidth:baseWidth baseCustomLineSpace:lineSpace];
}
return height;
}
@end
例子調用
UILabel *l = [[UILabel alloc] init];
l.backgroundColor = [UIColor orangeColor];
l.font = [UIFont systemFontOfSize:15];
l.textAlignment = NSTextAlignmentCenter;
l.numberOfLines = 0;
[self.view addSubview:l];
[l mas_makeConstraints:^(MASConstraintMaker *make) {
make.leading.mas_equalTo(50);
make.top.mas_equalTo(180);
make.trailing.mas_equalTo(-30);
}];
NSString *str? = @"阿薩德;卡上;當客服;愛迪生;開了房間啊;速度快了解放;阿卡麗束帶結發;案例看世界東方;阿卡麗世紀東方;阿卡麗束帶結發;阿卡麗束帶結發;卡死了都放假;";
NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithString:str];
NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
float lineSpace = 5.0;
[paragraphStyle setLineSpacing:lineSpace];
[attributedString addAttribute:NSParagraphStyleAttributeName value:paragraphStyle range:NSMakeRange(0, [str length])];
l.attributedText = attributedString;
CGFloat www = W - 80.0;
//? ? CGFloat h1 = [l returnTheLabelContentHeightWithContentStr:str baseWidth:www];
CGFloat h2 = [l returnTheLabelContentHeightWithContentStr:str baseWidth:www baseCustomLineSpace:lineSpace];
NSLog(@"=====%lf",h2);
CGFloat hh = [l returnTheConstraintsLabelContentHeightWithContentStr:str baseCustomLineSpace:lineSpace accordingToLabelSuperView:self.view];
NSLog(@"=======%lf",hh);
測試結果,h2 與 hh 高度一樣.
時間倉促,如果有問題或者不對的地方,敬請指正.謝謝
