即使图像较小，如何使UITableViewCell的ImageView成为固定大小

Question

我有一堆用于细胞图像视图的图像，它们都不超过50x50。例如40x50,50x32,20x37 .....

当我加载表格视图时，文本不会对齐，因为图像的宽度会有所不同。此外，我希望小图像出现在中心而不是左侧。

以下是我在'cellForRowAtIndexPath'方法中尝试的代码

cell.imageView.autoresizingMask = ( UIViewAutoresizingNone );
cell.imageView.autoresizesSubviews = NO;
cell.imageView.contentMode = UIViewContentModeCenter;
cell.imageView.bounds = CGRectMake(0, 0, 50, 50);
cell.imageView.frame = CGRectMake(0, 0, 50, 50);
cell.imageView.image = [UIImage imageWithData: imageData];

正如你所看到的，我已经尝试了一些东西，但它们都没有用。

Answer 1

没有必要重写所有内容。我建议改为：

将此内容发布在自定义单元格的.m文件中。

- (void)layoutSubviews {
    [super layoutSubviews];
    self.imageView.frame = CGRectMake(0,0,32,32);
}

这应该很好地完成。 ：

Answer 2

对于那些没有UITableViewCell的子类的人：

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
 [...]

      CGSize itemSize = CGSizeMake(40, 40);
      UIGraphicsBeginImageContextWithOptions(itemSize, NO, UIScreen.mainScreen.scale);
      CGRect imageRect = CGRectMake(0.0, 0.0, itemSize.width, itemSize.height);
      [cell.imageView.image drawInRect:imageRect];
      cell.imageView.image = UIGraphicsGetImageFromCurrentImageContext();
      UIGraphicsEndImageContext();

 [...]
     return cell;
}

上面的代码将大小设置为40x40。

Swift 2

    let itemSize = CGSizeMake(25, 25);
    UIGraphicsBeginImageContextWithOptions(itemSize, false, UIScreen.mainScreen().scale);
    let imageRect = CGRectMake(0.0, 0.0, itemSize.width, itemSize.height);
    cell.imageView?.image!.drawInRect(imageRect)
    cell.imageView?.image! = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

或者您可以使用@Tommy建议的其他（未经测试）方法：

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
 [...]

      CGSize itemSize = CGSizeMake(40, 40);
      UIGraphicsBeginImageContextWithOptions(itemSize, NO, 0.0)          
 [...]
     return cell;
}

Swift 3 +

let itemSize = CGSize.init(width: 25, height: 25)
UIGraphicsBeginImageContextWithOptions(itemSize, false, UIScreen.main.scale);
let imageRect = CGRect.init(origin: CGPoint.zero, size: itemSize)
cell?.imageView?.image!.draw(in: imageRect)
cell?.imageView?.image! = UIGraphicsGetImageFromCurrentImageContext()!;
UIGraphicsEndImageContext();

上面的代码是上面的Swift 3+版本。

Answer 3

我是怎么做到的。此技术负责将文本和详细文本标签适当地移动到左侧：

@interface SizableImageCell : UITableViewCell {}
@end
@implementation SizableImageCell
- (void)layoutSubviews {
    [super layoutSubviews];

    float desiredWidth = 80;
    float w=self.imageView.frame.size.width;
    if (w>desiredWidth) {
        float widthSub = w - desiredWidth;
        self.imageView.frame = CGRectMake(self.imageView.frame.origin.x,self.imageView.frame.origin.y,desiredWidth,self.imageView.frame.size.height);
        self.textLabel.frame = CGRectMake(self.textLabel.frame.origin.x-widthSub,self.textLabel.frame.origin.y,self.textLabel.frame.size.width+widthSub,self.textLabel.frame.size.height);
        self.detailTextLabel.frame = CGRectMake(self.detailTextLabel.frame.origin.x-widthSub,self.detailTextLabel.frame.origin.y,self.detailTextLabel.frame.size.width+widthSub,self.detailTextLabel.frame.size.height);
        self.imageView.contentMode = UIViewContentModeScaleAspectFit;
    }
}
@end

...

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    static NSString *CellIdentifier = @"Cell";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[[SizableImageCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier] autorelease];
        cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
    }

    cell.textLabel.text = ...
    cell.detailTextLabel.text = ...
    cell.imageView.image = ...
    return cell;
}

Answer 4

图像视图作为子视图添加到tableview单元格

UIImageView *imgView=[[UIImageView alloc] initWithFrame:CGRectMake(20, 5, 90, 70)];
imgView.backgroundColor=[UIColor clearColor];
[imgView.layer setCornerRadius:8.0f];
[imgView.layer setMasksToBounds:YES];
[imgView setImage:[UIImage imageWithData: imageData]];
[cell.contentView addSubview:imgView];

Answer 5

整个细胞不需要重新制作。您可以使用tableViewCells的indentationLevel和indentationWidth属性来移动单元格的内容。然后将自定义imageView添加到单元格的左侧。

Answer 6

简单 Swift ，

第1步：创建UITableViewCell的一个子类 第2步：将此方法添加到UITableViewCell的SubClass

override func layoutSubviews() {
    super.layoutSubviews()
    self.imageView?.frame = CGRectMake(0, 0, 10, 10)
}

第3步：使用cellForRowAtIndexPath中的子类创建单元格对象，

Ex: let customCell:CustomCell = CustomCell(style: UITableViewCellStyle.Default, reuseIdentifier: "Cell")

第4步：享受

Answer 7

更好地创建图像视图并将其作为子视图添加到单元格中。然后，您可以获得所需的帧大小。

Answer 8

UIImage *image = cell.imageView.image;

UIGraphicsBeginImageContext(CGSizeMake(35,35));
// draw scaled image into thumbnail context

[image drawInRect:CGRectMake(5, 5, 35, 35)]; //
UIImage *newThumbnail = UIGraphicsGetImageFromCurrentImageContext();
// pop the context
UIGraphicsEndImageContext();
if(newThumbnail == nil)
{
    NSLog(@"could not scale image");
    cell.imageView.image = image;
}
else
{
    cell.imageView.image = newThumbnail;
}

Answer 9

我使用@GermanAttanasio的答案创建了一个扩展程序。它提供了一种将图像大小调整为所需大小的方法，以及在向图像添加透明边距时执行相同操作的另一种方法（这对于您希望图像也具有边距的表视图非常有用）。 / p>

import UIKit

extension UIImage {

    /// Resizes an image to the specified size.
    ///
    /// - Parameters:
    ///     - size: the size we desire to resize the image to.
    ///
    /// - Returns: the resized image.
    ///
    func imageWithSize(size: CGSize) -> UIImage {

        UIGraphicsBeginImageContextWithOptions(size, false, UIScreen.mainScreen().scale);
        let rect = CGRectMake(0.0, 0.0, size.width, size.height);
        drawInRect(rect)

        let resultingImage = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();

        return resultingImage
    }

    /// Resizes an image to the specified size and adds an extra transparent margin at all sides of
    /// the image.
    ///
    /// - Parameters:
    ///     - size: the size we desire to resize the image to.
    ///     - extraMargin: the extra transparent margin to add to all sides of the image.
    ///
    /// - Returns: the resized image.  The extra margin is added to the input image size.  So that
    ///         the final image's size will be equal to:
    ///         `CGSize(width: size.width + extraMargin * 2, height: size.height + extraMargin * 2)`
    ///
    func imageWithSize(size: CGSize, extraMargin: CGFloat) -> UIImage {

        let imageSize = CGSize(width: size.width + extraMargin * 2, height: size.height + extraMargin * 2)

        UIGraphicsBeginImageContextWithOptions(imageSize, false, UIScreen.mainScreen().scale);
        let drawingRect = CGRect(x: extraMargin, y: extraMargin, width: size.width, height: size.height)
        drawInRect(drawingRect)

        let resultingImage = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();

        return resultingImage
    }
}

Answer 10

这对我来说非常有用：

创建UITableViewCell的子类（确保在故事板中链接您的单元格）

class MyTableCell:UITableViewCell{
    override func layoutSubviews() {
        super.layoutSubviews()

        if(self.imageView?.image != nil){

            let cellFrame = self.frame
            let textLabelFrame = self.textLabel?.frame
            let detailTextLabelFrame = self.detailTextLabel?.frame
            let imageViewFrame = self.imageView?.frame

            self.imageView?.contentMode = .ScaleAspectFill
            self.imageView?.clipsToBounds = true
            self.imageView?.frame = CGRectMake((imageViewFrame?.origin.x)!,(imageViewFrame?.origin.y)! + 1,40,40)
            self.textLabel!.frame = CGRectMake(50 + (imageViewFrame?.origin.x)! , (textLabelFrame?.origin.y)!, cellFrame.width-(70 + (imageViewFrame?.origin.x)!), textLabelFrame!.height)
            self.detailTextLabel!.frame = CGRectMake(50 + (imageViewFrame?.origin.x)!, (detailTextLabelFrame?.origin.y)!, cellFrame.width-(70 + (imageViewFrame?.origin.x)!), detailTextLabelFrame!.height)
        }
    }
}

在cellForRowAtIndexPath中，将单元格作为新单元格类型出列队列：

    let cell = tableView.dequeueReusableCellWithIdentifier("MyCell", forIndexPath: indexPath) as! MyTableCell

显然更改数字值以适合您的布局

Answer 11

常规UITableViewCell可以很好地定位事物，但是cell.imageView似乎没有像你想要的那样。我发现通过首先给cell.image查看正确大小的图像（如

），可以让UITableViewCell正确布局。

// Putting in a blank image to make sure text always pushed to the side.
UIGraphicsBeginImageContextWithOptions(CGSizeMake(kGroupImageDimension, kGroupImageDimension), NO, 0.0);
UIImage *blank = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
cell.imageView.image = blank;

然后，您可以使用

连接自己正常工作的UIImageView

// The cell.imageView increases in size to accomodate the image given it.
// We don't want this behaviour so we just attached a view on top of cell.imageView.
// This gives us the positioning of the cell.imageView without the sizing
// behaviour.
UIImageView *anImageView = nil;
NSArray *subviews = [cell.imageView subviews];
if ([subviews count] == 0)
{
    anImageView = [[UIImageView alloc] init];
    anImageView.translatesAutoresizingMaskIntoConstraints = NO;
    [cell.imageView addSubview:anImageView];

    NSLayoutConstraint *aConstraint = [NSLayoutConstraint constraintWithItem:anImageView attribute:NSLayoutAttributeCenterX relatedBy:NSLayoutRelationEqual toItem:cell.imageView attribute:NSLayoutAttributeCenterX multiplier:1.0 constant:0.0];
    [cell.imageView addConstraint:aConstraint];

    aConstraint = [NSLayoutConstraint constraintWithItem:anImageView attribute:NSLayoutAttributeCenterY relatedBy:NSLayoutRelationEqual toItem:cell.imageView attribute:NSLayoutAttributeCenterY multiplier:1.0 constant:0.0];
    [cell.imageView addConstraint:aConstraint];

    aConstraint = [NSLayoutConstraint constraintWithItem:anImageView attribute:NSLayoutAttributeWidth relatedBy:NSLayoutRelationEqual toItem:nil attribute:NSLayoutAttributeNotAnAttribute multiplier:0.0 constant:kGroupImageDimension];
    [cell.imageView addConstraint:aConstraint];

    aConstraint = [NSLayoutConstraint constraintWithItem:anImageView attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationEqual toItem:nil attribute:NSLayoutAttributeNotAnAttribute multiplier:0.0 constant:kGroupImageDimension];
    [cell.imageView addConstraint:aConstraint];
}
else
{
    anImageView = [subviews firstObject];
}

在onImageView上设置图像，它将执行您期望UIImageView执行的操作。无论您提供的图像如何，都是您想要的尺寸。这应该放在tableView：cellForRowAtIndexPath：

中

Answer 12

此解决方案基本上将图像绘制为“适合方面”。在给定的矩形内。

CGSize itemSize = CGSizeMake(80, 80);
UIGraphicsBeginImageContextWithOptions(itemSize, NO, UIScreen.mainScreen.scale);
UIImage *image = cell.imageView.image;

CGRect imageRect;
if(image.size.height > image.size.width) {
    CGFloat width = itemSize.height * image.size.width / image.size.height;
    imageRect = CGRectMake((itemSize.width - width) / 2, 0, width, itemSize.height);
} else {
    CGFloat height = itemSize.width * image.size.height / image.size.width;
    imageRect = CGRectMake(0, (itemSize.height - height) / 2, itemSize.width, height);
}

[cell.imageView.image drawInRect:imageRect];
cell.imageView.image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

Answer 13

这是@germanattanasio的工作方法，为 Swift 3 编写

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    ...
    cell.imageView?.image = myImage
    let itemSize = CGSize(width:42.0, height:42.0)
    UIGraphicsBeginImageContextWithOptions(itemSize, false, 0.0)
    let imageRect = CGRect(x:0.0, y:0.0, width:itemSize.width, height:itemSize.height)
    cell.imageView?.image!.draw(in:imageRect)
    cell.imageView?.image! = UIGraphicsGetImageFromCurrentImageContext()!
        UIGraphicsEndImageContext()
}

Answer 14

如果您使用cell.imageView?.translatesAutoresizingMaskIntoConstraints = false，则可以在imageView上设置约束。这是我在项目中使用的一个工作示例。我避免了子类化，并且不需要使用原型单元创建故事板，但确实花了我很长时间才能运行，所以最好只在没有更简单或更简洁的方式使用时使用。

override func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
    return 80
}



    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = UITableViewCell(style: .subtitle, reuseIdentifier: String(describing: ChangesRequiringApprovalTableViewController.self))

    let record = records[indexPath.row]

    cell.textLabel?.text = "Title text"

    if let thumb = record["thumbnail"] as? CKAsset, let image = UIImage(contentsOfFile: thumb.fileURL.path) {
        cell.imageView?.contentMode = .scaleAspectFill
        cell.imageView?.image = image
        cell.imageView?.translatesAutoresizingMaskIntoConstraints = false
        cell.imageView?.leadingAnchor.constraint(equalTo: cell.contentView.leadingAnchor).isActive = true
        cell.imageView?.widthAnchor.constraint(equalToConstant: 80).rowHeight).isActive = true
        cell.imageView?.heightAnchor.constraint(equalToConstant: 80).isActive = true
        if let textLabel = cell.textLabel {
            let margins = cell.contentView.layoutMarginsGuide
            textLabel.translatesAutoresizingMaskIntoConstraints = false
            cell.imageView?.trailingAnchor.constraint(equalTo: textLabel.leadingAnchor, constant: -8).isActive = true
            textLabel.topAnchor.constraint(equalTo: margins.topAnchor).isActive = true
            textLabel.trailingAnchor.constraint(equalTo: margins.trailingAnchor).isActive = true
            let bottomConstraint = textLabel.bottomAnchor.constraint(equalTo: margins.bottomAnchor)
            bottomConstraint.priority = UILayoutPriorityDefaultHigh
            bottomConstraint.isActive = true
            if let description = cell.detailTextLabel {
                description.translatesAutoresizingMaskIntoConstraints = false
                description.bottomAnchor.constraint(equalTo: margins.bottomAnchor).isActive = true
                description.trailingAnchor.constraint(equalTo: margins.trailingAnchor).isActive = true
                cell.imageView?.trailingAnchor.constraint(equalTo: description.leadingAnchor, constant: -8).isActive = true
                textLabel.bottomAnchor.constraint(equalTo: description.topAnchor).isActive = true
            }
        }
        cell.imageView?.clipsToBounds = true
    }

    cell.detailTextLabel?.text = "Detail Text"

    return cell
}

Answer 15

我有同样的问题。谢谢所有其他回答的人-我能够使用部分答案中的一部分找到解决方案。

我的解决方案是使用Swift 5

我们要解决的问题是，TableViewCell中的图像可能具有不同的长宽比，但是我们希望它们以一致的宽度进行渲染。图像当然应该没有失真地渲染并填充整个空间。就我而言，我可以“裁剪”一些高个，瘦的图像，所以我使用了内容模式.scaleAspectFill

为此，我创建了UITableViewCell的自定义子类。就我而言，我将其命名为StoryTableViewCell。整个课程都粘贴在下面，并带有内联注释。

当我还使用自定义附件视图和长文本标签时，这种方法对我有用。这是最终结果的图像：

Rendered Table View with consistent image width

class StoryTableViewCell: UITableViewCell {

    override func layoutSubviews() {
        super.layoutSubviews()

        // ==== Step 1 ====
        // ensure we have an image
        guard let imageView = self.imageView else {return}

        // create a variable for the desired image width
        let desiredWidth:CGFloat = 70;

        // get the width of the image currently rendered in the cell
        let currentImageWidth = imageView.frame.size.width;

        // grab the width of the entire cell's contents, to be used later
        let contentWidth = self.contentView.bounds.width

        // ==== Step 2 ====
        // only update the image's width if the current image width isn't what we want it to be
        if (currentImageWidth != desiredWidth) {
            //calculate the difference in width
            let widthDifference = currentImageWidth - desiredWidth;

            // ==== Step 3 ====
            // Update the image's frame,
            // maintaining it's original x and y values, but with a new width
            self.imageView?.frame = CGRect(imageView.frame.origin.x,
                                           imageView.frame.origin.y,
                                           desiredWidth,
                                           imageView.frame.size.height);

            // ==== Step 4 ====
            // If there is a texst label, we want to move it's x position to
            // ensure it isn't overlapping with the image, and that it has proper spacing with the image
            if let textLabel = self.textLabel
            {
                let originalFrame = self.textLabel?.frame

                // the new X position for the label is just the original position,
                // minus the difference in the image's width
                let newX = textLabel.frame.origin.x - widthDifference
                self.textLabel?.frame = CGRect(newX,
                                               textLabel.frame.origin.y,
                                               contentWidth - newX,
                                               textLabel.frame.size.height);
                print("textLabel info: Original =\(originalFrame!)", "updated=\(self.textLabel!.frame)")
            }

            // ==== Step 4 ====
            // If there is a detail text label, do the same as step 3
            if let detailTextLabel = self.detailTextLabel {
                let originalFrame = self.detailTextLabel?.frame
                let newX = detailTextLabel.frame.origin.x-widthDifference
                self.detailTextLabel?.frame = CGRect(x: newX,
                                                     y: detailTextLabel.frame.origin.y,
                                                     width: contentWidth - newX,
                                                     height: detailTextLabel.frame.size.height);
                print("detailLabel info: Original =\(originalFrame!)", "updated=\(self.detailTextLabel!.frame)")
            }

            // ==== Step 5 ====
            // Set the image's content modoe to scaleAspectFill so it takes up the entire view, but doesn't get distorted
            self.imageView?.contentMode = .scaleAspectFill;
        }
    }
}

Answer 16

我们最终得到的解决方案与许多其他解决方案类似。但是要获得分隔符的正确位置，我们必须在调用super.layoutSubviews()之前将其设置好。简化示例：

class ImageTableViewCell: UITableViewCell {

    override func layoutSubviews() {
        separatorInset.left = 70
        super.layoutSubviews()

        imageView?.frame = CGRect(x: 0, y: 0, width: 50, height: 50)
        textLabel?.frame = CGRect(x: 70, y: 0, width: 200, height: 50)
    }

}