如何在UICollectionViewCell上显示标准复选标记？ [英] How do I display the standard checkmark on a UICollectionViewCell?
本文介绍了如何在UICollectionViewCell上显示标准复选标记？的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我正在设计一个带有UICollectionView的iOS应用程序，我希望用户能够在此视图中选择多个项目。似乎Apple在这种情况下使用了标准的复选标记。例如，在下图中，您可以在共享表中选择多张照片时看到它。
根据。这是他们的样子：
它们是用矢量图形绘制的，所以无论你想要什么尺寸，它们都会很棒。这些是30x30。我还提供了一个选项，可以在未选择项目时使用灰色选中标记而不是空心圆圈。
要使用这些选项，请将以下类复制到项目中。然后，将UIView添加到storyboard或xib，并将其自定义类设置为SSCheckMark。
SSCheckMark.h
#import< UIKit / UIKit.h>
typedef NS_ENUM（NSUInteger，SSCheckMarkStyle）
{
SSCheckMarkStyleOpenCircle，
SSCheckMarkStyleGrayedOut
};
@interface SSCheckMark：UIView
@property（readwrite）bool checked;
@property（readwrite）SSCheckMarkStyle checkMarkStyle;
@end
SSCheckMark.m
#importSSCheckMark.h
@implementation SSCheckMark
- （void）drawRect：（CGRect ）rect
{
[super drawRect：rect];
if（self.checked）
[self drawRectChecked：rect];
else
{
if（self.checkMarkStyle == SSCheckMarkStyleOpenCircle）
[self drawRectOpenCircle：rect];
else if（self.checkMarkStyle == SSCheckMarkStyleGrayedOut）
[self drawRectGrayedOut：rect];
}
}
- （无效）setChecked :( bool）选中
{
_checked = checked;
[self setNeedsDisplay];
}
- （void）setCheckMarkStyle：（SSCheckMarkStyle）checkMarkStyle
{
_checkMarkStyle = checkMarkStyle;
[self setNeedsDisplay];
}
- （void）drawRectChecked：（CGRect）rect
{
////一般声明
CGContextRef context = UIGraphicsGetCurrentContext（）;
////颜色声明
UIColor * checkmarkBlue2 = [UIColor colorWithRed：0.078绿色：0.435蓝色：0.875 alpha：1];
////暗影声明
UIColor * shadow2 = [UIColor blackColor];
CGSize shadow2Offset = CGSizeMake（0.1，-0.1）;
CGFloat shadow2BlurRadius = 2.5;
////帧
CGRect frame = self.bounds;
////子帧
CGRect组= CGRectMake（CGRectGetMinX（帧）+ 3，CGRectGetMinY（帧）+ 3，CGRectGetWidth（帧） - 6，CGRectGetHeight（帧） - 6） ;
////组
{
//// CheckedOval绘图
UIBezierPath * checkedOvalPath = [UIBezierPath bezierPathWithOvalInRect：CGRectMake（CGRectGetMinX（group） + floor（CGRectGetWidth（group）* 0.00000 + 0.5），CGRectGetMinY（group）+ floor（CGRectGetHeight（group）* 0.00000 + 0.5），floor（CGRectGetWidth（group）* 1.00000 + 0.5） - floor（CGRectGetWidth（group）* 0.00000 + 0.5），floor（CGRectGetHeight（group）* 1.00000 + 0.5） - floor（CGRectGetHeight（group）* 0.00000 + 0.5））];
CGContextSaveGState（context）;
CGContextSetShadowWithColor（context，shadow2Offset，shadow2BlurRadius，shadow2.CGColor）;
[checkmarkBlue2 setFill];
[checkedOvalPath fill];
CGContextRestoreGState（context）;
[[UIColor whiteColor] setStroke];
checkedOvalPath.lineWidth = 1;
[checkedOvalPath stroke];
//// Bezier绘图
UIBezierPath * bezierPath = [UIBezierPath bezierPath];
[bezierPath moveToPoint：CGPointMake（CGRectGetMinX（group）+ 0.27083 * CGRectGetWidth（group），CGRectGetMinY（group）+ 0.54167 * CGRectGetHeight（group））];
[bezierPath addLineToPoint：CGPointMake（CGRectGetMinX（group）+ 0.41667 * CGRectGetWidth（group），CGRectGetMinY（group）+ 0.68750 * CGRectGetHeight（group））];
[bezierPath addLineToPoint：CGPointMake（CGRectGetMinX（group）+ 0.75000 * CGRectGetWidth（group），CGRectGetMinY（group）+ 0.35417 * CGRectGetHeight（group））];
bezierPath.lineCapStyle = kCGLineCapSquare;
[[UIColor whiteColor] setStroke];
bezierPath.lineWidth = 1.3;
[bezierPath stroke];
}
}
- （void）drawRectGrayedOut：（CGRect）rect
{
////一般声明
CGContextRef context = UIGraphicsGetCurrentContext（）;
////颜色声明
UIColor * grayTranslucent = [UIColor colorWithRed：1绿色：1蓝色：1 alpha：0.6];
////暗影声明
UIColor * shadow2 = [UIColor blackColor];
CGSize shadow2Offset = CGSizeMake（0.1，-0.1）;
CGFloat shadow2BlurRadius = 2.5;
////帧
CGRect frame = self.bounds;
////子帧
CGRect组= CGRectMake（CGRectGetMinX（帧）+ 3，CGRectGetMinY（帧）+ 3，CGRectGetWidth（帧） - 6，CGRectGetHeight（帧） - 6） ;
////组
{
//// UncheckedOval绘图
UIBezierPath * uncheckedOvalPath = [UIBezierPath bezierPathWithOvalInRect：CGRectMake（CGRectGetMinX（group） + floor（CGRectGetWidth（group）* 0.00000 + 0.5），CGRectGetMinY（group）+ floor（CGRectGetHeight（group）* 0.00000 + 0.5），floor（CGRectGetWidth（group）* 1.00000 + 0.5） - floor（CGRectGetWidth（group）* 0.00000 + 0.5），floor（CGRectGetHeight（group）* 1.00000 + 0.5） - floor（CGRectGetHeight（group）* 0.00000 + 0.5））];
CGContextSaveGState（context）;
CGContextSetShadowWithColor（context，shadow2Offset，shadow2BlurRadius，shadow2.CGColor）;
[grayTranslucent setFill];
[uncheckedOvalPath fill];
CGContextRestoreGState（context）;
[[UIColor whiteColor] setStroke];
uncheckedOvalPath.lineWidth = 1;
[uncheckedOvalPath stroke];
//// Bezier绘图
UIBezierPath * bezierPath = [UIBezierPath bezierPath];
[bezierPath moveToPoint：CGPointMake（CGRectGetMinX（group）+ 0.27083 * CGRectGetWidth（group），CGRectGetMinY（group）+ 0.54167 * CGRectGetHeight（group））];
[bezierPath addLineToPoint：CGPointMake（CGRectGetMinX（group）+ 0.41667 * CGRectGetWidth（group），CGRectGetMinY（group）+ 0.68750 * CGRectGetHeight（group））];
[bezierPath addLineToPoint：CGPointMake（CGRectGetMinX（group）+ 0.75000 * CGRectGetWidth（group），CGRectGetMinY（group）+ 0.35417 * CGRectGetHeight（group））];
bezierPath.lineCapStyle = kCGLineCapSquare;
[[UIColor whiteColor] setStroke];
bezierPath.lineWidth = 1.3;
[bezierPath stroke];
}
}
- （void）drawRectOpenCircle：（CGRect）rect
{
////一般声明
CGContextRef context = UIGraphicsGetCurrentContext（）;
////暗影声明
UIColor * shadow = [UIColor blackColor];
CGSize shadowOffset = CGSizeMake（0.1，-0.1）;
CGFloat shadowBlurRadius = 0.5;
UIColor * shadow2 = [UIColor blackColor];
CGSize shadow2Offset = CGSizeMake（0.1，-0.1）;
CGFloat shadow2BlurRadius = 2.5;
////帧
CGRect frame = self.bounds;
////子帧
CGRect组= CGRectMake（CGRectGetMinX（帧）+ 3，CGRectGetMinY（帧）+ 3，CGRectGetWidth（帧） - 6，CGRectGetHeight（帧） - 6） ;
////组
{
//// EmptyOval绘图
UIBezierPath * emptyOvalPath = [UIBezierPath bezierPathWithOvalInRect：CGRectMake（CGRectGetMinX（group） + floor（CGRectGetWidth（group）* 0.00000 + 0.5），CGRectGetMinY（group）+ floor（CGRectGetHeight（group）* 0.00000 + 0.5），floor（CGRectGetWidth（group）* 1.00000 + 0.5） - floor（CGRectGetWidth（group）* 0.00000 + 0.5），floor（CGRectGetHeight（group）* 1.00000 + 0.5） - floor（CGRectGetHeight（group）* 0.00000 + 0.5））];
CGContextSaveGState（context）;
CGContextSetShadowWithColor（context，shadow2Offset，shadow2BlurRadius，shadow2.CGColor）;
CGContextRestoreGState（context）;
CGContextSaveGState（context）;
CGContextSetShadowWithColor（context，shadowOffset，shadowBlurRadius，shadow.CGColor）;
[[UIColor whiteColor] setStroke];
emptyOvalPath.lineWidth = 1;
[emptyOvalPath stroke];
CGContextRestoreGState（context）;
}
}
@end
I'm designing an iOS app with a UICollectionView, and I'd like users to be able to select multiple items within this view. It seems there's a standard style of checkmark Apple uses in this kind of situation. For example, in the image below you can see it when selecting multiple photos in a share sheet.
According to the documentation, you are responsible for updating the UI of your cells to reflect their selection state. I know on a UITableViewCell you can set the accessoryType property to add a checkmark, but I can't seem to find any equivalent for a UICollectionViewCell.
Is there a way Apple provides to use this checkmark in my app, besides trying to rip this icon out of a screenshot?
解决方案
I ended up recreating the checkmarks using PaintCode. Here's what they look like:
They're drawn with vector graphics, so they'll look great at whatever size you want. These are 30x30. I also included an option to use a grayed-out checkmark instead of the open circle when an item is not selected.
To use these, copy the following class into your project. Then, add a UIView to your storyboard or xib, and set its custom class to SSCheckMark.
SSCheckMark.h
#import <UIKit/UIKit.h>
typedef NS_ENUM( NSUInteger, SSCheckMarkStyle )
{
SSCheckMarkStyleOpenCircle,
SSCheckMarkStyleGrayedOut
};
@interface SSCheckMark : UIView
@property (readwrite) bool checked;
@property (readwrite) SSCheckMarkStyle checkMarkStyle;
@end
SSCheckMark.m
#import "SSCheckMark.h"
@implementation SSCheckMark
- (void) drawRect:(CGRect)rect
{
[super drawRect:rect];
if ( self.checked )
[self drawRectChecked:rect];
else
{
if ( self.checkMarkStyle == SSCheckMarkStyleOpenCircle )
[self drawRectOpenCircle:rect];
else if ( self.checkMarkStyle == SSCheckMarkStyleGrayedOut )
[self drawRectGrayedOut:rect];
}
}
- (void) setChecked:(bool)checked
{
_checked = checked;
[self setNeedsDisplay];
}
- (void) setCheckMarkStyle:(SSCheckMarkStyle)checkMarkStyle
{
_checkMarkStyle = checkMarkStyle;
[self setNeedsDisplay];
}
- (void) drawRectChecked: (CGRect) rect
{
//// General Declarations
CGContextRef context = UIGraphicsGetCurrentContext();
//// Color Declarations
UIColor* checkmarkBlue2 = [UIColor colorWithRed: 0.078 green: 0.435 blue: 0.875 alpha: 1];
//// Shadow Declarations
UIColor* shadow2 = [UIColor blackColor];
CGSize shadow2Offset = CGSizeMake(0.1, -0.1);
CGFloat shadow2BlurRadius = 2.5;
//// Frames
CGRect frame = self.bounds;
//// Subframes
CGRect group = CGRectMake(CGRectGetMinX(frame) + 3, CGRectGetMinY(frame) + 3, CGRectGetWidth(frame) - 6, CGRectGetHeight(frame) - 6);
//// Group
{
//// CheckedOval Drawing
UIBezierPath* checkedOvalPath = [UIBezierPath bezierPathWithOvalInRect: CGRectMake(CGRectGetMinX(group) + floor(CGRectGetWidth(group) * 0.00000 + 0.5), CGRectGetMinY(group) + floor(CGRectGetHeight(group) * 0.00000 + 0.5), floor(CGRectGetWidth(group) * 1.00000 + 0.5) - floor(CGRectGetWidth(group) * 0.00000 + 0.5), floor(CGRectGetHeight(group) * 1.00000 + 0.5) - floor(CGRectGetHeight(group) * 0.00000 + 0.5))];
CGContextSaveGState(context);
CGContextSetShadowWithColor(context, shadow2Offset, shadow2BlurRadius, shadow2.CGColor);
[checkmarkBlue2 setFill];
[checkedOvalPath fill];
CGContextRestoreGState(context);
[[UIColor whiteColor] setStroke];
checkedOvalPath.lineWidth = 1;
[checkedOvalPath stroke];
//// Bezier Drawing
UIBezierPath* bezierPath = [UIBezierPath bezierPath];
[bezierPath moveToPoint: CGPointMake(CGRectGetMinX(group) + 0.27083 * CGRectGetWidth(group), CGRectGetMinY(group) + 0.54167 * CGRectGetHeight(group))];
[bezierPath addLineToPoint: CGPointMake(CGRectGetMinX(group) + 0.41667 * CGRectGetWidth(group), CGRectGetMinY(group) + 0.68750 * CGRectGetHeight(group))];
[bezierPath addLineToPoint: CGPointMake(CGRectGetMinX(group) + 0.75000 * CGRectGetWidth(group), CGRectGetMinY(group) + 0.35417 * CGRectGetHeight(group))];
bezierPath.lineCapStyle = kCGLineCapSquare;
[[UIColor whiteColor] setStroke];
bezierPath.lineWidth = 1.3;
[bezierPath stroke];
}
}
- (void) drawRectGrayedOut: (CGRect) rect
{
//// General Declarations
CGContextRef context = UIGraphicsGetCurrentContext();
//// Color Declarations
UIColor* grayTranslucent = [UIColor colorWithRed: 1 green: 1 blue: 1 alpha: 0.6];
//// Shadow Declarations
UIColor* shadow2 = [UIColor blackColor];
CGSize shadow2Offset = CGSizeMake(0.1, -0.1);
CGFloat shadow2BlurRadius = 2.5;
//// Frames
CGRect frame = self.bounds;
//// Subframes
CGRect group = CGRectMake(CGRectGetMinX(frame) + 3, CGRectGetMinY(frame) + 3, CGRectGetWidth(frame) - 6, CGRectGetHeight(frame) - 6);
//// Group
{
//// UncheckedOval Drawing
UIBezierPath* uncheckedOvalPath = [UIBezierPath bezierPathWithOvalInRect: CGRectMake(CGRectGetMinX(group) + floor(CGRectGetWidth(group) * 0.00000 + 0.5), CGRectGetMinY(group) + floor(CGRectGetHeight(group) * 0.00000 + 0.5), floor(CGRectGetWidth(group) * 1.00000 + 0.5) - floor(CGRectGetWidth(group) * 0.00000 + 0.5), floor(CGRectGetHeight(group) * 1.00000 + 0.5) - floor(CGRectGetHeight(group) * 0.00000 + 0.5))];
CGContextSaveGState(context);
CGContextSetShadowWithColor(context, shadow2Offset, shadow2BlurRadius, shadow2.CGColor);
[grayTranslucent setFill];
[uncheckedOvalPath fill];
CGContextRestoreGState(context);
[[UIColor whiteColor] setStroke];
uncheckedOvalPath.lineWidth = 1;
[uncheckedOvalPath stroke];
//// Bezier Drawing
UIBezierPath* bezierPath = [UIBezierPath bezierPath];
[bezierPath moveToPoint: CGPointMake(CGRectGetMinX(group) + 0.27083 * CGRectGetWidth(group), CGRectGetMinY(group) + 0.54167 * CGRectGetHeight(group))];
[bezierPath addLineToPoint: CGPointMake(CGRectGetMinX(group) + 0.41667 * CGRectGetWidth(group), CGRectGetMinY(group) + 0.68750 * CGRectGetHeight(group))];
[bezierPath addLineToPoint: CGPointMake(CGRectGetMinX(group) + 0.75000 * CGRectGetWidth(group), CGRectGetMinY(group) + 0.35417 * CGRectGetHeight(group))];
bezierPath.lineCapStyle = kCGLineCapSquare;
[[UIColor whiteColor] setStroke];
bezierPath.lineWidth = 1.3;
[bezierPath stroke];
}
}
- (void) drawRectOpenCircle: (CGRect) rect
{
//// General Declarations
CGContextRef context = UIGraphicsGetCurrentContext();
//// Shadow Declarations
UIColor* shadow = [UIColor blackColor];
CGSize shadowOffset = CGSizeMake(0.1, -0.1);
CGFloat shadowBlurRadius = 0.5;
UIColor* shadow2 = [UIColor blackColor];
CGSize shadow2Offset = CGSizeMake(0.1, -0.1);
CGFloat shadow2BlurRadius = 2.5;
//// Frames
CGRect frame = self.bounds;
//// Subframes
CGRect group = CGRectMake(CGRectGetMinX(frame) + 3, CGRectGetMinY(frame) + 3, CGRectGetWidth(frame) - 6, CGRectGetHeight(frame) - 6);
//// Group
{
//// EmptyOval Drawing
UIBezierPath* emptyOvalPath = [UIBezierPath bezierPathWithOvalInRect: CGRectMake(CGRectGetMinX(group) + floor(CGRectGetWidth(group) * 0.00000 + 0.5), CGRectGetMinY(group) + floor(CGRectGetHeight(group) * 0.00000 + 0.5), floor(CGRectGetWidth(group) * 1.00000 + 0.5) - floor(CGRectGetWidth(group) * 0.00000 + 0.5), floor(CGRectGetHeight(group) * 1.00000 + 0.5) - floor(CGRectGetHeight(group) * 0.00000 + 0.5))];
CGContextSaveGState(context);
CGContextSetShadowWithColor(context, shadow2Offset, shadow2BlurRadius, shadow2.CGColor);
CGContextRestoreGState(context);
CGContextSaveGState(context);
CGContextSetShadowWithColor(context, shadowOffset, shadowBlurRadius, shadow.CGColor);
[[UIColor whiteColor] setStroke];
emptyOvalPath.lineWidth = 1;
[emptyOvalPath stroke];
CGContextRestoreGState(context);
}
}
@end
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