Question

如何使用像http://img.abc.com/noPhoto4530.gif这样的链接创建带有图像的UIImageView？

Answer 1

NSURL *url = [NSURL URLWithString:@"http://img.abc.com/noPhoto4530.gif"];
NSData *data = [NSData dataWithContentsOfURL:url];
UIImage *image = [UIImage imageWithData:data];
UIImageView *imageView = [[UIImageView alloc] initWithImage:image];

Answer 2

如果你想在后台下载图片，然后在主线程上设置它，你可以这样做：

- (void)downloadPicture {

        dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{

                NSURL *url = [NSURL URLWithString:@"http://img.abc.com/noPhoto4530.gif"];

                UIImage *image = [self getPicture:url];

                dispatch_async(dispatch_get_main_queue(), ^{

                    [self setPicture:image];

                });
            });
}

 - (UIImage *)getPicture:(NSURL *)pictureURL {

        NSData *data = [NSData dataWithContentsOfURL:pictureURL];
        UIImage *image = [UIImage imageWithData:data];

        return image;    
}

 - (void)setPicture:(UIImage *)image {

        UIImageView * imageView = [[UIImageView alloc] initWithFrame:
                               CGRectMake(kPictureX, kPictureY, image.size.height, image.size.width)];

        [imageView setImage:image];

        [self.view addSubview: imageView];

}

Answer 3

以下是那些希望使用iOS 7的新NSURLSession类套件的代码片段：

// Set NSURLSessionConfig to be a default session
NSURLSessionConfiguration *config = [NSURLSessionConfiguration defaultSessionConfiguration];

// Create session using config
NSURLSession *session = [NSURLSession sessionWithConfiguration:config];

// Create URL
NSURL *url = [NSURL URLWithString:@"https://www.google.com/images/srpr/logo11w.png"];

// Create URL request
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
request.HTTPMethod = @"GET";

// Create data task
NSURLSessionDataTask *getDataTask = [session dataTaskWithRequest:request completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {

    // Okay, now we have the image data (on a background thread)
    UIImage *image = [UIImage imageWithData:data];

    // We want to update our UI so we switch to the main thread
    dispatch_async(dispatch_get_main_queue(), ^{

        // Create image view using fetched image (or update an existing one)
        UIImageView *imageView = [[UIImageView alloc] initWithImage:image];

        // Do whatever other UI updates are needed here on the main thread...
    });
}];

// Execute request
[getDataTask resume];

Answer 4

将图片下载到设备上的本地路径，然后从imageWithContentsOfFile获取UIImage，并使用此设置UIImageView中的图片。记得有时清理你的图像文件。

Answer 5

下载图像后，您还需要将其作为子视图放置在视图中，如下所示：

NSURL *url = [NSURL URLWithString:@"http://img.abc.com/noPhoto4530.gif"];
NSData *data = [NSData dataWithContentsOfURL:url];
UIImage *image = [UIImage imageWithData:data];

UIImageView * myImageView = [[UIImageView alloc] initWithImage:image];
[someOtherView addSubview:myImageView];
[myImageView release];

Answer 6

您可以按照here所述进行操作，也可以使用NSURLConnection下载图像数据并创建UIImage以设置为UIImageView。我个人更喜欢使用NSURLConnection异步下载图像。

Answer 7

这里可以有相同的答案

NSURL *urlLink = [NSURL URLWithString:@"http://img.abc.com/noPhoto4530.gif"];
NSData *dataURL = [NSData dataWithContentsOfURL:urlLink];
UIImage *imageData = [UIImage imageWithData:dataURL];
UIImageView *imageView = [[UIImageView alloc] initWithImage:imageData];

Answer 8

你可以试试现代gcd风格（xcode 8.0 +）：

let queue = DispatchQueue(label: "com.mydomain.queue3")
queue.async {
    let imageURL: URL = URL(string: "https://www.brightedge.com/blog/wp-content/uploads/2014/08/Google-Secure-Search_SEL.jpg")!
    guard let imageData = try? Data(contentsOf: imageURL) else {
        return
    }
    DispatchQueue.main.async {
        self.imageView.image = UIImage(data: imageData)
    }
}

您还可以将第一个DispatchQueue替换为URLSession.dataTask

let imageURL: URL = URL(string: "https://www.brightedge.com/blog/wp-content/uploads/2014/08/Google-Secure-Search_SEL.jpg")!

(URLSession(configuration: URLSessionConfiguration.default)).dataTask(with: imageURL, completionHandler: { (imageData, response, error) in

    if let data = imageData {
        print("Did download image data")

        DispatchQueue.main.async {
            self.imageView.image = UIImage(data: data)
        }
    }
}).resume()

如何使用链接中的图像创建UIImageView？

8 个答案: