ios 自定義0.5的線條UIView

這是本人第一次寫有關ios的博客，也不知道要寫什麼內容，所以先把自己隨手弄的一個自定義View給搞上來，大家覺得好用的話也可以拿去用，後期我再優化一下，感覺在佈局那塊還是蠻好用的，當然，如果你們這羣大神有更好的用法請通知我，我剛涉及ios不久。

在ios xib佈局文件中，用自動佈局約束的時候，UIView的寬和高最小隻能設置1，而不能設置0.5之類的，然後在運行的時候會發現線條太粗，影響整體美觀。

一般出現這種問題的時候我都會選擇自己定義一條線條，然後就在項目上通用，如果是代碼生成的UIView當線條的話，自然可以生成0.5寬高的線條，但是在自動佈局約束的時候就沒辦法了，所以我基於約束佈局的情況下定義的線條。

這裏最重要的是在代碼實現xib佈局中的約束條件，針對約束這一塊，我到時候會另外總結一篇文章出來，然後下面我就直接貼代碼了，可以直接用，還封裝得不是很好。具體我今天優化了一下，把上一次遺留的三個問題都解決了，然後用起來更加方便了

LineView.h

//
//  LineView.h
//  cafe
//
//  Created by xihao on 17/1/13.
//  Copyright © 2017年 yidont. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface LineView : UIView

//@property (nonatomic) BOOL isVertical;

@property (strong,nonatomic)IBOutlet NSString* key_direction;

@property (strong,nonatomic)IBOutlet UIColor * key_color;

//設置線條顏色
-(void)setLineColor:(UIColor*)color;

@end

LineView.m

//
//  LineView.m
//  cafe
//
//  Created by xihao on 17/1/13.
//  Copyright © 2017年 yidont. All rights reserved.
//

#import "LineView.h"

#define LINE_COLOR [UIColor colorWithRed:220/255.0f green:220/255.0f blue:220/255.0f alpha:1.0] //線條顏色

@implementation LineView{
    BOOL isVertical;
    UIView* lineV;
}

-(void)awakeFromNib{
    [super awakeFromNib];
    [self initView];
}


-(void)initView{

    NSLog(@"線條方向==%@",self.key_direction);

    CGRect frame=self.frame;

    NSLog(@"line_h=%i,w=%i,ww=%i",(int)frame.size.height,(int)frame.size.width,(int)SCREEN_W);



    NSArray* array=self.constraints;
    for(NSLayoutConstraint* constraint in array){
        if (constraint.firstAttribute == NSLayoutAttributeHeight) {
            isVertical=false;
        }
        if (constraint.firstAttribute == NSLayoutAttributeWidth) {
            isVertical=true;
        }
    }



    lineV=[[UIView alloc]init];
    lineV.translatesAutoresizingMaskIntoConstraints = NO;
    [self addSubview:lineV];



    if (isVertical) {

        NSLayoutConstraint *top=[NSLayoutConstraint constraintWithItem:lineV attribute:NSLayoutAttributeTop relatedBy:NSLayoutRelationEqual toItem:self attribute:NSLayoutAttributeTop multiplier:1 constant:0];
        top.active=YES;

        NSLayoutConstraint *bottom=[NSLayoutConstraint constraintWithItem:lineV attribute:NSLayoutAttributeBottom relatedBy:NSLayoutRelationEqual toItem:self attribute:NSLayoutAttributeBottom multiplier:1 constant:0];
        bottom.active=YES;

        NSLayoutConstraint *width=[NSLayoutConstraint constraintWithItem:lineV attribute:NSLayoutAttributeWidth relatedBy:NSLayoutRelationEqual toItem:nil attribute:NSLayoutAttributeWidth multiplier:1 constant:0.5f];
        width.active=YES;


        if ([self.key_direction isEqualToString:@"left"]) {
            NSLayoutConstraint *leading=[NSLayoutConstraint constraintWithItem:lineV attribute:NSLayoutAttributeLeading relatedBy:NSLayoutRelationEqual toItem:self attribute:NSLayoutAttributeLeading multiplier:1 constant:0];
            leading.active=YES;
        }else if([self.key_direction isEqualToString:@"right"]){
            NSLayoutConstraint *trailing=[NSLayoutConstraint constraintWithItem:lineV attribute:NSLayoutAttributeTrailing relatedBy:NSLayoutRelationEqual toItem:self attribute:NSLayoutAttributeTrailing multiplier:1 constant:0];
            trailing.active=YES;
        }else{
            NSLayoutConstraint *centerX=[NSLayoutConstraint constraintWithItem:lineV attribute:NSLayoutAttributeCenterX relatedBy:NSLayoutRelationEqual toItem:self attribute:NSLayoutAttributeCenterX multiplier:1 constant:0];
            centerX.active=YES;
        }

    }else{
        NSLayoutConstraint *leading=[NSLayoutConstraint constraintWithItem:lineV attribute:NSLayoutAttributeLeading relatedBy:NSLayoutRelationEqual toItem:self attribute:NSLayoutAttributeLeading multiplier:1 constant:0];
        leading.active=YES;

        NSLayoutConstraint *trailing=[NSLayoutConstraint constraintWithItem:lineV attribute:NSLayoutAttributeTrailing relatedBy:NSLayoutRelationEqual toItem:self attribute:NSLayoutAttributeTrailing multiplier:1 constant:0];
        trailing.active=YES;

        NSLayoutConstraint *height=[NSLayoutConstraint constraintWithItem:lineV attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationEqual toItem:nil attribute:NSLayoutAttributeHeight multiplier:1 constant:0.5f];
        height.active=YES;


        if ([self.key_direction isEqualToString:@"top"]) {
            NSLayoutConstraint *top=[NSLayoutConstraint constraintWithItem:lineV attribute:NSLayoutAttributeTop relatedBy:NSLayoutRelationEqual toItem:self attribute:NSLayoutAttributeTop multiplier:1 constant:0];
            top.active=YES;
        }else if([self.key_direction isEqualToString:@"bottom"]){
            NSLayoutConstraint *bottom=[NSLayoutConstraint constraintWithItem:lineV attribute:NSLayoutAttributeBottom relatedBy:NSLayoutRelationEqual toItem:self attribute:NSLayoutAttributeBottom multiplier:1 constant:0];
            bottom.active=YES;
        }else{
            NSLayoutConstraint *centerY=[NSLayoutConstraint constraintWithItem:lineV attribute:NSLayoutAttributeCenterY relatedBy:NSLayoutRelationEqual toItem:self attribute:NSLayoutAttributeCenterY multiplier:1 constant:0];
            centerY.active=YES;
        }

    }
    if (self.key_color!=nil) {
        [lineV setBackgroundColor:self.key_color];
    }else{
        [lineV setBackgroundColor:LINE_COLOR];
    }


}


-(void)setLineColor:(UIColor *)color{
    [lineV setBackgroundColor:color];
}


@end