UILabel,UIButton等控件动态折行,居中

控件宽度,个数都不确定的情况下, 实现折行和居中效果. 这里以UILabel 和 UIButton为例 , 其他控件思路一致 .

左对齐版:

先看下效果图:

左对齐效果.png

@property (weak, nonatomic) IBOutlet NSLayoutConstraint *bgHeight;

@property (nonatomic, strong) NSArray *scoreArrs;
@property (nonatomic, assign) int lineNum;
@property (nonatomic, strong) UIButton *lastbtn;

@property (nonatomic, strong) NSMutableArray *btnArr;

-(NSArray *)scoreArrs{
    if (_scoreArrs == nil) {
        _scoreArrs = @[@"112",@"这个放不下",@"112",@"112",@"这个放不下",@"112"];
    }
    return _scoreArrs;
}
-(NSMutableArray *)btnArr{
    if (_btnArr == nil) {
        _btnArr = [[NSMutableArray alloc] init];
    }
    return _btnArr;
}

具体实现:

//设置热搜按钮
-(void)setupBtnView{
    
    self.lineNum = 0;
    CGFloat margin = 10;
    CGFloat between = 11;
    for (int i = 0; i < self.scoreArrs.count; i++) {
        
        UIButton *btn = [[UIButton alloc] init];
        [btn setTitle:self.scoreArrs[i] forState:UIControlStateNormal];
        [btn setTitle:self.scoreArrs[i] forState:UIControlStateHighlighted];
        btn.tag = i;
        UIFont *fnt = [UIFont fontWithName:@"HelveticaNeue" size:14.0f];
        btn.titleLabel.textAlignment = NSTextAlignmentCenter;
        btn.titleLabel.font = fnt;
        btn.layer.cornerRadius = 4;

        btn.layer.masksToBounds = YES;
        [btn setBackgroundColor:kFormator_COLOR];
        [btn addTarget:self action:@selector(clickWithBtn:) forControlEvents:UIControlEventTouchUpInside];
        [btn setTitleColor:kGRAY_COLOR forState:UIControlStateNormal];
        
        CGSize size = [btn.titleLabel.text sizeWithAttributes:[NSDictionary dictionaryWithObjectsAndKeys:fnt,NSFontAttributeName, nil]];
        CGFloat nameH = size.height + 14;
        CGFloat nameW = size.width + 20;
        if (i == 0) {
            btn.frame = CGRectMake(margin, self.lineNum * nameH +margin, nameW,nameH);
            self.lastbtn = btn;
        } else {
            
            CGFloat tempSpace = btnView.frame.size.width - CGRectGetMaxX(self.lastbtn.frame)- margin - between;
            if (tempSpace >= nameW) {
                
                btn.frame = CGRectMake(CGRectGetMaxX(self.lastbtn.frame)+ between, self.lineNum * (nameH + between)+margin, nameW,nameH);
                
            } else {
                
                self.lineNum ++;
                btn.frame = CGRectMake(margin, self.lineNum * (nameH + between)+margin, nameW,nameH);
                
            }
            self.lastbtn = btn;
            
        }
        
        if (i == self.scoreArrs.count -1) {
            self.bgHeight.constant = CGRectGetMaxY(btn.frame) + margin;
        }
        
        [btnView addSubview:btn];
        
    }
    
}```
#### 居中版:
先看下效果图:
![居中版效果图.png](http://upload-images.jianshu.io/upload_images/1307566-006f45d6ed051943.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240)

@property (weak, nonatomic) IBOutlet UIButton *bgview;
@property (nonatomic, strong) NSArray *scoreArrs;
@property (weak, nonatomic) IBOutlet NSLayoutConstraint *bgHeight;

@property (nonatomic, strong) UIButton *lastbtn;

@property (nonatomic, assign) int lineNum;

@property (nonatomic, strong) NSMutableArray *btnArr;
@property (nonatomic, strong) NSMutableArray *tempArr;

@property (nonatomic, strong) UIButton *tempLastbtn;```

-(NSArray *)scoreArrs{
    if (_scoreArrs == nil) {
        _scoreArrs = @[@"112",@"112",@"112",@"112",@"这个放不下",@"112",@"112",@"这个放不下",@"这个放不下",@"这个放不下",@"这个放不下",@"这个放不下",@"这个放不下",@"112",@"112",@"这个放不下",@"112",@"112",@"这个放不下",@"这个放不下",@"112",@"112",@"这个放不下",@"这个放不下",@"这个放不下",@"这个放不下",@"这个放不下",@"这个放不下",@"112",@"112",@"这个放不下",@"112",@"112",@"这个放不下",@"112"];
    }
    return _scoreArrs;
}
-(NSMutableArray *)btnArr{
    if (_btnArr == nil) {
        _btnArr = [[NSMutableArray alloc] init];
    }
    return _btnArr;
}

-(NSMutableArray *)tempArr{
    if (_tempArr == nil) {
        _tempArr = [[NSMutableArray alloc] init];
    }
    return _tempArr;
}

具体实现:

self.lineNum = 0;
    CGFloat margin = 10;
    CGFloat between = 8;
    
    for (int i = 0; i= nameW) {
                
                btn.frame = CGRectMake(CGRectGetMaxX(self.lastbtn.frame)+ between, self.lineNum * (nameH + between)+margin, nameW,nameH);
                [self.btnArr addObject:btn];

            } else {
                for (int j = 0; j

- (void)clickWithBtn:(UIButton *)btn{
    
    btn.selected = !btn.selected;
    if (btn.selected) {
        [btn setBackgroundColor:[UIColor redColor]];
        [btn setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];

    } else {
        [btn setBackgroundColor:[UIColor whiteColor]];
        [btn setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];


    }
    
}

注:居中实现方式有点问题, 不应该用Y值来判断, 应该使用计数num来判断, 更准确 .