整理IOS开发常用小Tips

浏览数：33 / 时间：2015年06月11日

在NavigationController中重写 show／pushViewController方法统一在导航栏中添加按钮

- (void)showViewController:(UIViewController *)vc sender:(id)sender

{

    if (self.viewControllers.count > 0) { //首页不显示跳转可以通过只添加leftBtn来间接修改所有返回按钮的图片

    vc.hidesBottomBarWhenPushed = YES;

    vc.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc]initWithTitle:@"left" style:UIBarButtonItemStylePlain target:self action:@selector(back)];

    vc.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemCamera target:self action:nil];

    }
    [super showViewController:vc sender:sender];

}

- (void)back
{
[self popViewControllerAnimated:YES];
}

计算文件/文件夹体积并删除

NSFileManager *mgr = [NSFileManager defaultManager];

    NSString *rootPath = @"/Users/wanghong/Desktop/test";

    NSArray *subPaths = [mgr subpathsAtPath:rootPath];

    long long totolSize = 0;

    for (NSString *pathString in subPaths) {
        NSString *path = [rootPath stringByAppendingPathComponent:pathString];
        //NSLog(@"%@",path);

        BOOL dir = NO;

        [mgr fileExistsAtPath:path isDirectory:&dir];
        if (dir == NO) {

            totolSize += [[mgr attributesOfItemAtPath:path error:nil][NSFileSize] longLongValue];
        }
    }

    CGFloat size = totolSize/1000.0/1000.0; //size结果字节为单位
    _sizeLabel.text = [NSString stringWithFormat:@"%fMB",size];

    //CLEAN
    [mgr removeItemAtPath:rootPath error:nil];

修改UIView或其子类的边框为圆角

[btn.layer setCornerRadius:(btn.frame.size.height/2)];

btn.layer.borderWidth = 2.0f;

self.diskBtn.layer.masksToBounds = YES;(有时候需要裁剪)

SDWebImage 清除位于ache文件夹下的缓存

[[SDWebImageManager sharedManager].imageCache clearDisk]; 用clear不是clean

将image存储到相机胶卷中

UIImage *image = [UIImage imageNamed:@"ceshi"];
UIImageWriteToSavedPhotosAlbum(image, NULL, NULL, NULL);

创建屏幕快照，返回UIView（用CoreGraphic可以转为UIImage）

[self.view snapshotViewAfterScreenUpdates:NO]

UIPanGestureRecognizer 有时候会影响 UITableView 的 Scroll 操作。由于你已经设置了 Cell 的 Pan 手势识别器的 UIGestureRecognizerDelegate ，你只需要实现一个（有些滑稽且冗长命名的） delegate 方法即可将一切恢复正常。

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
return NO;

}

利用UIWebView播放GIF

NSData *gif = [NSData dataWithContentsOfFile: [[NSBundle mainBundle] pathForResource:self.imageName ofType:@"gif"]];
    self.gifView = [[UIWebView alloc]init];
    self.gifView.frame = CGRectMake(0, 0, self.frame.size.width, kCellHeight);

    self.gifView.userInteractionEnabled = NO;
    [self.gifView loadData:gif MIMEType:@"image/gif" textEncodingName:nil baseURL:nil];

self.gifView.scalesPageToFit = YES;

重写push控制器的方法取消导航控制器的动画
- (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated
{
// 不需要动画
[super pushViewController:viewController animated:NO];

}

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整理IOS开发常用小Tips