iOS 提升开发效率(工具类别)

1.自定义UITextField.placeholder颜色

新建UITextField类别

.h

@interface UITextField (LXExtension)
/** 占位文字颜色 */
@property (nonatomic, strong) UIColor *lx_placeholderColor;
@end

.m

@implementation UITextField (LXExtension)
/** 通过这个属性名，就可以修改textField内部的占位文字颜色 */
static NSString * const LXPlaceholderColorKeyPath = @"placeholderLabel.textColor";
/**
 *  设置占位文字颜色
 */
- (void)setLx_placeholderColor:(UIColor *)lx_placeholderColor
{
    // 这3行代码的作用：1> 保证创建出placeholderLabel，2> 保留曾经设置过的占位文字
    NSString *placeholder = self.placeholder;
    self.placeholder = @" ";
    self.placeholder = placeholder;
    // 处理xmg_placeholderColor为nil的情况：如果是nil，恢复成默认的占位文字颜色
    if (lx_placeholderColor == nil) {
        lx_placeholderColor = [UIColor colorWithRed:0 green:0 blue:0.0980392 alpha:0.22];
    }
    // 设置占位文字颜色
    [self setValue:lx_placeholderColor forKeyPath:LXPlaceholderColorKeyPath];
}
/**
 *  获得占位文字颜色
 */
- (UIColor *)lx_placeholderColor
{
    return [self valueForKeyPath:LXPlaceholderColorKeyPath];
}
@end

2.快速自定义导航栏按钮

新建UIBarButtonItem类别
.h

@interface UIBarButtonItem (LXExtension)
+ (instancetype)lx_itemWithImage:(NSString *)image highImage:(NSString *)highImage target:(id)target action:(SEL)action;
@end

.m

@implementation UIBarButtonItem (XMGExtension)
+ (instancetype)lx_itemWithImage:(NSString *)image highImage:(NSString *)highImage target:(id)target action:(SEL)action
{
    UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
    [button setImage:[UIImage imageNamed:image] forState:UIControlStateNormal];
    [button setImage:[UIImage imageNamed:highImage] forState:UIControlStateHighlighted];
    [button sizeToFit];
    [button addTarget:target action:action forControlEvents:UIControlEventTouchUpInside];
    return [[self alloc] initWithCustomView:button];
}
@end

3.计算文件大小,生成缓存,计算文本尺寸
新建NSString类别
.h

@interface NSString (LXExtension)
/**
 *  md5加密
 */
+ (NSString*)md5HexDigest:(NSString*)input;
/**
 *  根据文件名计算出文件大小
 */
- (unsigned long long)lx_fileSize;
/**
 *  生成缓存目录全路径
 */
- (instancetype)cacheDir;
/**
 *  生成文档目录全路径
 */
- (instancetype)docDir;
/**
 *  生成临时目录全路径
 */
- (instancetype)tmpDir;

/**
 *  @brief 根据字数的不同,返回UILabel中的text文字需要占用多少Size
 *  @param size 约束的尺寸
 *  @param font 文本字体
 *  @return 文本的实际尺寸
 */
- (CGSize)textSizeWithContentSize:(CGSize)size font:(UIFont *)font;

/**
 *  @brief  根据文本字数/文本宽度约束/文本字体 求得text的Size
 *  @param width 宽度约束
 *  @param font  文本字体
 *  @return 文本的实际高度
 */
- (CGFloat)textHeightWithContentWidth:(CGFloat)width font:(UIFont *)font;

/**
 *  @brief  根据文本字数/文本宽度约束/文本字体 求得text的Size
 *  @param height 宽度约束
 *  @param font  文本字体
 *  @return 文本的实际长度
 */
- (CGFloat)textWidthWithContentHeight:(CGFloat)height font:(UIFont *)font;
@end

.m

#import "NSString+LXExtension.h"
#import <objc/runtime.h>
#import <CommonCrypto/CommonDigest.h>

/*CC_MD5_DIGEST_LENGTH*/

#define  MD5_LENGTH   32
@implementation NSString (LXExtension)

+ (NSString*)md5HexDigest:(NSString*)input {
    const char* str = [input UTF8String];
    unsigned char result[CC_MD5_DIGEST_LENGTH];
    CC_MD5(str, strlen(str), result);
    
    NSMutableString *ret = [NSMutableString stringWithCapacity:CC_MD5_DIGEST_LENGTH*2];
    for(int i = 0; i<CC_MD5_DIGEST_LENGTH; i++) {
        [ret appendFormat:@"%02x",result[i]];
    }
    return ret;
}

- (unsigned long long)lx_fileSize
{
    // 计算self这个文件夹\文件的大小
    
    // 文件管理者
    NSFileManager *mgr = [NSFileManager defaultManager];
    
    // 文件类型
    NSDictionary *attrs = [mgr attributesOfItemAtPath:self error:nil];
    NSString *fileType = attrs.fileType;
    
    if ([fileType isEqualToString:NSFileTypeDirectory]) { // 文件夹
        // 获得文件夹的遍历器
        NSDirectoryEnumerator *enumerator = [mgr enumeratorAtPath:self];
        
        // 总大小
        unsigned long long fileSize = 0;
        
        // 遍历所有子路径
        for (NSString *subpath in enumerator) {
            // 获得子路径的全路径
            NSString *fullSubpath = [self stringByAppendingPathComponent:subpath];
            fileSize += [mgr attributesOfItemAtPath:fullSubpath error:nil].fileSize;
        }
        
        return fileSize;
    }
    
    // 文件
    return attrs.fileSize;
}

- (instancetype)cacheDir
{
    NSString *dir = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject];
    return [dir stringByAppendingPathComponent:[self lastPathComponent]];
}
- (instancetype)docDir
{
    NSString *dir = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];
    return [dir stringByAppendingPathComponent:[self lastPathComponent]];
}

- (instancetype)tmpDir
{
    NSString *dir = NSTemporaryDirectory();
    return [dir stringByAppendingPathComponent:[self lastPathComponent]];
}

- (CGSize)textSizeWithContentSize:(CGSize)size font:(UIFont *)font {
    return [self boundingRectWithSize:size options:NSStringDrawingUsesLineFragmentOrigin attributes:@{NSFontAttributeName : font} context:nil].size;
}

- (CGFloat)textHeightWithContentWidth:(CGFloat)width font:(UIFont *)font {
    CGSize size = CGSizeMake(width, MAXFLOAT);
    return [self textSizeWithContentSize:size font:font].height;
}

- (CGFloat)textWidthWithContentHeight:(CGFloat)height font:(UIFont *)font {
    CGSize size = CGSizeMake(MAXFLOAT, height);
    return [self textSizeWithContentSize:size font:font].width;
}

@end