Question

您好我正在使用SDWebImage加载图片确定没问题

这里我从服务中获取图片，我想调整这些图片的大小，我想使用SDWebImage加载它们

为此我写了下面的代码

Obj.imageYH---> this is imageURL

  NSData *imageData = [[NSData alloc] initWithContentsOfURL:[NSURL URLWithString:Obj.imageYH]];

    UIImage *actualImage = [UIImage imageWithData:imageData];
    UIGraphicsBeginImageContext(CGSizeMake(150, 150));
    [actualImage drawInRect:CGRectMake(0,0,150, 150)];
    UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    NSData *smallData = UIImagePNGRepresentation(newImage);

    NSString *Finalstring = [[NSString alloc] initWithData:smallData encoding:NSUTF8StringEncoding] ;


    [Mainimage sd_setImageWithURL:[NSURL URLWithString: Finalstring] placeholderImage:[UIImage imageNamed:@"collectionViewIcon.png"]];

但是在上面的代码中，我在Finalstring中获得了空值。如何调整大小以及如何使用SDWebImage加载图像？

Answer 1

第1步：安装SDWebImage

首先，请确保您使用的是最新版本的SDWebImage，并通过CocoaPods安装（不建议手动链接库）。

您的Podfile应包含以下行：

pod 'SDWebImage', '~>3.7'

之后，关闭Xcode项目并在项目目录中运行pod install。安装后使用Xcode 工作区。

第2步：使用代码

首先，您已导入库

#import <SDWebImage/UIImageView+WebCache.h>

此时，请尝试清洁＆amp;构建工作区。如果一切顺利，项目应该没有错误地构建。

然后，在你的函数中：

SDWebImageManager *manager = [SDWebImageManager sharedManager];
[manager downloadImageWithURL:Obj.imageYH
                  options:0
                 progress:^(NSInteger receivedSize, NSInteger expectedSize) {
                     // progression tracking code, optional. 
                     // You can set the progress block to nil
                 }
                 completed:^(UIImage *image, NSError *error, SDImageCacheType cacheType, BOOL finished, NSURL *imageURL) {
                     if (image) {
                         // Resize your image here, then set it to UIImageView
                         Mainimage.image = [UIImage imageWithData:UIImagePNGRepresentation(image) scale:0.5f]; 
                         // resize to 0.5x, function available since iOS 6
                     }
                 }];

进行。

Answer 2

 SDWebImageManager *manager = [SDWebImageManager sharedManager];
 [manager downloadWithURL:url delegate:self options:0 success:^(UIImage
 *image)  {
     cell.profilePicture.image = [self imageByScalingAndCroppingForSize:CGSizeMake(cell.profilePicture.frame.size.width,
 cell.profilePicture.frame.size.height) image:image]; } failure:nil];

不要忘记包含

#import <SDWebImage/UIImageView+WebCache.h>
@interface YourViewController : UIViewController <SDWebImageManagerDelegate>

Answer 3

使用以下代码行代替您的代码：

UIImage *actualImage = [UIImage imageWithData:imageData];
UIGraphicsBeginImageContext(CGSizeMake(150, 150));
[actualImage drawInRect:CGRectMake(0,0,150, 150)];
UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
NSData *smallData = UIImagePNGRepresentation(newImage);

[smallData writeToFile:Finalstring atomically:YES];// Finalstring is file path of resize image 

[Mainimage sd_setImageWithURL:[NSURL URLWithString: Finalstring] placeholderImage:[UIImage imageNamed:@"collectionViewIcon.png"]];

如何使用SDWebImage库

3 个答案: