ios筆記 可視化程式設計字型大小适配

建立個UIButton類目, 名字叫AutoFontSize;

.h檔案代碼

#import <UIKit/UIKit.h>

#import <objc/runtime.h>

@interface UIButton (AutoFontSize)

@end

@interface UILabel (AutoFontSize)

@end

@interface UITextField (AutoFontSize)

@end

@interface UITextView (AutoFontSize)

@end

.m檔案代碼

#import "UIButton+AutoFontSize.h"

@implementation UIButton (AutoFontSize)

+ (void)load{

    Method imp =class_getInstanceMethod([selfclass], @selector(initWithCoder:));

    Method myImp =class_getInstanceMethod([selfclass], @selector(myInitWithCoder:));

    method_exchangeImplementations(imp, myImp);

}

- (id)myInitWithCoder:(NSCoder*)aDecode{

    [selfmyInitWithCoder:aDecode];

    if (self) {

        //部分不像改變字型的把tag值設定成333跳過

        if(self.titleLabel.tag != 333){

            CGFloat fontSize =self.titleLabel.font.pointSize;

            self.titleLabel.font = [UIFontsystemFontOfSize:fontSize *OffWidth];

        }

    }

    returnself;

}

@end

@implementation UILabel (AutoFontSize)

+ (void)load{

    Method imp =class_getInstanceMethod([selfclass], @selector(initWithCoder:));

    Method myImp =class_getInstanceMethod([selfclass], @selector(myInitWithCoder:));

    method_exchangeImplementations(imp, myImp);

}

- (id)myInitWithCoder:(NSCoder*)aDecode{

    [selfmyInitWithCoder:aDecode];

    if (self) {

        NSLog(@"%@",self.font);

        //部分不像改變字型的把tag值設定成333跳過

        if(self.tag != 333){

            CGFloat fontSize =self.font.pointSize;

            self.font = [UIFontsystemFontOfSize:fontSize *OffWidth - 1];

        }

    }

    returnself;

}

@end

@implementation UITextField (AutoFontSize)

+ (void)load{

    Method imp =class_getInstanceMethod([selfclass], @selector(initWithCoder:));

    Method myImp =class_getInstanceMethod([selfclass], @selector(myInitWithCoder:));

    method_exchangeImplementations(imp, myImp);

}

- (id)myInitWithCoder:(NSCoder*)aDecode{

    [selfmyInitWithCoder:aDecode];

    if (self) {

        //部分不像改變字型的把tag值設定成333跳過

        if(self.tag != 333){

            CGFloat fontSize =self.font.pointSize;

            self.font = [UIFontsystemFontOfSize:fontSize *OffWidth];

        }

    }

    returnself;

}

@end

@implementation UITextView (AutoFontSize)

+ (void)load{

    Method imp =class_getInstanceMethod([selfclass], @selector(initWithCoder:));

    Method myImp =class_getInstanceMethod([selfclass], @selector(myInitWithCoder:));

    method_exchangeImplementations(imp, myImp);

}

- (id)myInitWithCoder:(NSCoder*)aDecode{

    [selfmyInitWithCoder:aDecode];

    if (self) {

        //部分不像改變字型的把tag值設定成333跳過

        if(self.tag != 333){

            CGFloat fontSize =self.font.pointSize;

            self.font = [UIFontsystemFontOfSize:fontSize *OffWidth];

        }

    }

    returnself;

}

@end

在pch檔案裡import

#import "UIButton+AutoFontSize.h"

完事

原理:

 中二點的叫rutime黑魔法 :method_exchangeImplementations 交換系統方法, 當系統需要調用initWithCoder方法時使其不去調用initWithCoder而是去調用自己定義的- myInitWithCoder方法, 在方法裡把字型大小乘上螢幕比例