如何在Table View中将图像添加到行动作？

Question

从右侧滑动单元格时如何添加自定义图像以删除按钮UITableview,如下图所示？

 func tableView(tableView: UITableView, editActionsForRowAtIndexPath indexPath: NSIndexPath) -> [UITableViewRowAction]? {

    let remove = UITableViewRowAction(style: .Default, title: "\nRemove") { action, indexPath in }
    remove.backgroundColor = UIColor(patternImage: UIImage(named: "remove")!) }

从上面的代码中可以看到Image,但它显示为堆叠在一起的一组图像.我的意思是,我无法设置"ContentMode"到".ScaleToAspectFit"了"UIImage"

这种方法的最佳方法是什么？

示例代码可能很明显.

Answer 1

基本上,您正在绘制上下文,然后从上下文中检索新图像.

let label = UILabel(frame: CGRect(x: 0, y: 0, width: 80, height: 100))
label.text = "ADD"
label.textAlignment = .Center
label.textColor = UIColor.whiteColor()

let img: UIImage = UIImage(named: "delete")

UIGraphicsBeginImageContextWithOptions(imgSize, false, UIScreen.mainScreen().scale)
let context = UIGraphicsGetCurrentContext()

// Set background color
CGContextSetFillColorWithColor(context, UIColor.raangeRed().CGColor)
CGContextFillRect(context, CGRect(x: 0, y: 0, width: 80, height: 80))

// Draw image
img.drawInRect(CGRectMake(30, 15, 20, 20))

// Draw View
label.layer.renderInContext(context!)

// Retrieve new UIImage
let newImage: UIImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()

let deleteRowAction = UITableViewRowAction(style: .Normal, title: "           ") { (rowAction, indexPath) in
     // Do stuff   
    }
deleteRowAction.backgroundColor = UIColor(patternImage: newImage)

您还可以创建自定义视图(使用UIImageView和UILabel)并在上下文中呈现它.

Answer 2

灵感来自Denny的回答.这是他的代码的objective-c版本.

- (NSArray *)tableView:(UITableView *)tableView editActionsForRowAtIndexPath:(NSIndexPath *)indexPath {

    UITableViewRowAction *deleteAction = [UITableViewRowAction rowActionWithStyle:UITableViewRowActionStyleDefault title:@"           " handler:^(UITableViewRowAction *action, NSIndexPath *indexPath)
    {
        UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"Do you really want to delete this comment?" message:@"" delegate:self cancelButtonTitle:@"NO" otherButtonTitles:@"YES", nil];

        [alertView setTag:101];
        [alertView show];
    }];

    UITableViewCell *commentCell = (UITableViewCell *)[tableView cellForRowAtIndexPath:indexPath];

    CGFloat height = commentCell.frame.size.height;

    UIImage *backgroundImage = [self deleteImageForHeight:height];

    deleteAction.backgroundColor = [UIColor colorWithPatternImage:backgroundImage];

    return @[deleteAction];
}

以下是图像绘制方法:

- (UIImage*)deleteImageForHeight:(CGFloat)height{

    CGRect frame = CGRectMake(0, 0, 62, height);

    UIGraphicsBeginImageContextWithOptions(CGSizeMake(62, height), NO, [UIScreen mainScreen].scale);

    CGContextRef context = UIGraphicsGetCurrentContext();

    CGContextSetFillColorWithColor(context, [UIColor redColor].CGColor);
    CGContextFillRect(context, frame);

    UIImage *image = [UIImage imageNamed:@"icon-delete"];

    [image drawInRect:CGRectMake(frame.size.width/2.0, frame.size.height/2.0 - 10, 18, 20)];

    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    return newImage;
}

结果是:

Answer 3

尝试这个

let backImage = UIImageView(image: UIImage(named: "remove"))
backImage.contentMode = .scaleAspectFit
remove.backgroundColor = UIColor(patternImage:backImage.image!)

选择2

var img: UIImage = UIImage(named: "remove")
var imgSize: CGSize = tableView.frame.size
UIGraphicsBeginImageContext(imgSize)
img.drawInRect(CGRectMake(20, 0, 20, 20))
var newImage: UIImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
remove.backgroundColor = UIColor(patternImage: newImage)