动态新增UIButton

因为工程中要用到，所以自己写了一个这样的控件
实现比较简单，这里继承了UIButoon类 重写了这个方法

• (CGRect)imageRectForContentRect:(CGRect)contentRect

这里还有几个方法是对按钮的扩展

具体实现参照如下：
HomeMoreViewController.h文件

#import <UIKit/UIKit.h>
@interface MoreButton : UIButton
@end

@interface HomeMoreViewController : UIViewController
@property (retain, nonatomic) NSMutableArray *listArr;

@end

HomeMoreViewController.m文件

#import "HomeMoreViewController.h"

@implementation MoreButton

- (CGRect)imageRectForContentRect:(CGRect)contentRect{
    return CGRectMake((ScreenWidth/4-50)/2, 5, 50, 50);
}
@end

@interface HomeMoreViewController ()

@end

@implementation HomeMoreViewController
@synthesize FirstDelegate;

- (void)viewDidLoad {
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor whiteColor];
    
    self.title = @"更多";
    UIColor * color = [UIColor blackColor];
    NSDictionary *attributes=[NSDictionary dictionaryWithObjectsAndKeys:color,NSForegroundColorAttributeName,nil];
    [self.navigationController.navigationBar setTitleTextAttributes:attributes];
    
    UIButton *backBtn = [UIButton buttonWithType:UIButtonTypeCustom];
    backBtn.frame = CGRectMake(0, 0, 32, 32);
    backBtn.titleLabel.font = [UIFont fontWithName:imagefont size: 16];
    [backBtn setTitle:@"\U0000e80e" forState:UIControlStateNormal];
    [backBtn setTitleColor:key_BgColorF6E forState:UIControlStateNormal];
    backBtn.contentHorizontalAlignment = UIControlContentHorizontalAlignmentLeft;
    [backBtn addTarget:self action:@selector(doBack:) forControlEvents:UIControlEventTouchUpInside];
    
    UIBarButtonItem *rightItem = [[UIBarButtonItem alloc] initWithCustomView:backBtn];
    self.navigationItem.leftBarButtonItem = rightItem;
    
    

    float y = 64.0;
    float w = [UIScreen mainScreen].bounds.size.width;
    float h = 75;
    
    NSInteger num = self.listArr.count;//(ps:这里显示按钮的数量，我这边是api接口提供的数据，根据自己的项目需求来吧！)
    
    w = [UIScreen mainScreen].bounds.size.width/4;
    
    
    for (int i = 0; i<num; i++) {
        MoreButton *Btn = [MoreButton buttonWithType:UIButtonTypeCustom];
        Btn.frame = CGRectMake((i-(floor(i/4))*4)*w, y+(floor(i/4))*h, w, h);
        Btn.imageView.contentMode = UIViewContentModeScaleAspectFit;
        Btn.tag = i;
        Btn.contentHorizontalAlignment = UIControlContentHorizontalAlignmentCenter;
        [Btn setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
        Btn.titleLabel.adjustsFontSizeToFitWidth=YES;
        [Btn addTarget:self action:@selector(setMethond:) forControlEvents:UIControlEventTouchUpInside];
        //缩略图
        NSString * imageStr = [NSString stringWithFormat:@"%@", [[self.listArr objectAtIndex:i] objectForKey:@"image"]];
        NSURL *imageurl = [NSURL URLWithString:imageStr];
        SDWebImageManager *manager = [SDWebImageManager sharedManager];
        [manager downloadImageWithURL:imageurl options:SDWebImageRetryFailed progress:^(NSInteger receivedSize, NSInteger expectedSize) {
        } completed:^(UIImage *image, NSError *error, SDImageCacheType cacheType, BOOL finished, NSURL *imageURL) {
            //                UIImage *myimage  = [self imageByScalingAndCroppingForSize:<#(CGSize)#> :<#(UIImage *)#>:image :CGSizeMake(50, 50)];
            UIImage *myimage = [self circleImageWithName:image borderWidth:1.0 borderColor:[UIColor whiteColor]];
           //这里可以对按钮进行图片的设置，我这里的图片资源是api接口提供  如果不需要设置按钮图片的话可以直接忽略这里的代码  直接在上面设置按钮的文字什么的
        }];
        Btn.clipsToBounds = YES;
        [self.view addSubview:Btn];
    }
}

- (void)doBack:(id)sender
{
    [self.navigationController dismissViewControllerAnimated:YES completion:nil];
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (void)setMethond:(UIButton *)sender{
   
}

- (UIImage *)circleImageWithName:(UIImage *)name borderWidth:(CGFloat)borderWidth borderColor:(UIColor *)borderColor
{
    // 1.加载原图
    //    UIImage *oldImage = [self OriginImage:name scaleToSize:CGSizeMake(name.size.width*(iPhone5?0.67:1), name.size.height*(iPhone5?0.67:1))];
    UIImage *oldImage = name;
    // 2.开启上下文
    CGFloat imageW = oldImage.size.width ;
    CGFloat imageH = oldImage.size.height;
    CGSize imageSize = CGSizeMake(imageW, imageH);
    UIGraphicsBeginImageContextWithOptions(imageSize, NO, 0.0);
    
    // 3.取得当前的上下文,这里得到的就是上面刚创建的那个图片上下文
    CGContextRef ctx = UIGraphicsGetCurrentContext();
    
    // 4.画边框(大圆)
    [borderColor set];
    CGFloat bigRadius = imageW * 0.5; // 大圆半径
    CGFloat centerX = bigRadius; // 圆心
    CGFloat centerY = bigRadius;
    CGContextAddArc(ctx, centerX, centerY, bigRadius, 0, M_PI * 2, 0);
    CGContextFillPath(ctx); // 画圆。As a side effect when you call this function, Quartz clears the current path.
    
    // 5.小圆
    CGFloat smallRadius = bigRadius - borderWidth;
    CGContextAddArc(ctx, centerX, centerY, smallRadius, 0, M_PI * 2, 0);
    // 裁剪(后面画的东西才会受裁剪的影响)
    CGContextClip(ctx);
    
    // 6.画图
    [oldImage drawInRect:CGRectMake(borderWidth, borderWidth, oldImage.size.width, oldImage.size.height)];
    
    // 7.取图
    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
    
    // 8.结束上下文
    UIGraphicsEndImageContext();
    
    return newImage;
}