如何在 iOS 6 中计算给定宽度的 NSAttributedString 的高度
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How to calculate the height of an NSAttributedString with given width in iOS 6
提问by Jake
Possible Duplicate:
How to get height for NSAttributedString at a fixed width
Now NSAttributedString is available in iOS 6. For layout purposes, I want to know how to calculate the required height of an NSAttributedString under fixed width. I'm looking for something that's equivalent to NSString's - (CGSize)sizeWithFont:(UIFont *)font constrainedToSize:(CGSize)sizebut for NSAttributedString.
现在 NSAttributedString 在 iOS 6 中可用。出于布局目的，我想知道如何计算固定宽度下 NSAttributedString 的所需高度。我正在寻找与 NSString 相同- (CGSize)sizeWithFont:(UIFont *)font constrainedToSize:(CGSize)size但用于 NSAttributedString 的东西。
To calculate the drawing size of NSAttributedStrings, there are two methods available:
要计算 NSAttributedStrings 的绘图大小，有两种方法可用：
- (CGSize)sizecan't be used because it does not take any width into consideration.- I tried
- (CGRect)boundingRectWithSize:(CGSize)size options:(NSStringDrawingOptions)options context:(NSStringDrawingContext *)context, but somehow it doesn't give me the correct height. I think the method is buggy. If I run the following code, it gives mebounding size: 572.324951, 19.000000ignoring the given width of 200. It should give me something like 100 of height.
- (CGSize)size不能使用，因为它没有考虑任何宽度。- 我试过了
- (CGRect)boundingRectWithSize:(CGSize)size options:(NSStringDrawingOptions)options context:(NSStringDrawingContext *)context，但不知何故它没有给我正确的高度。我认为这个方法有问题。如果我运行以下代码，它会bounding size: 572.324951, 19.000000忽略给定的宽度 200。它应该给我类似 100 的高度。
NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] init];
NSDictionary *attributes = @{NSFontAttributeName : [UIFont fontWithName:@"HelveticaNeue" size:15], NSForegroundColorAttributeName : [UIColor blueColor]};
[attributedString appendAttributedString:[[NSAttributedString alloc] initWithString:@"Attributed String\n" attributes:attributes]];
[attributedString appendAttributedString:[[NSAttributedString alloc] initWithString:@"Attributed String\n" attributes:attributes]];
[attributedString appendAttributedString:[[NSAttributedString alloc] initWithString:@"Attributed String\n" attributes:attributes]];
[attributedString appendAttributedString:[[NSAttributedString alloc] initWithString:@"Attributed String\n" attributes:attributes]];
[attributedString appendAttributedString:[[NSAttributedString alloc] initWithString:@"Attributed String\n" attributes:attributes]];
CGRect frame = [attributedString boundingRectWithSize:CGSizeMake(200, 1000) options:0 context:nil];
NSLog(@"bounding size: %f, %f", frame.size.width, frame.size.height);
There are other methods available for Mac OS X, but not for iOS.
还有其他方法可用于 Mac OS X，但不适用于 iOS。
回答by rmaddy
Option 2 does work in iOS with the proper parameters.
选项 2 在 iOS 中使用适当的参数确实有效。
NSAttributedString *attrStr = ... // your attributed string
CGFloat width = 300; // whatever your desired width is
CGRect rect = [attrStr boundingRectWithSize:CGSizeMake(width, 10000) options:NSStringDrawingUsesLineFragmentOrigin | NSStringDrawingUsesFontLeading context:nil];
Without the proper values for the optionsparameter you will get the wrong height.
如果没有正确的options参数值，您将得到错误的高度。
It is also required that attrStrcontains a font attribute. Without a font, there is no way to properly calculate the size.
还需要attrStr包含字体属性。没有字体，就无法正确计算大小。
