iPhone 上的 UILabel 尺寸计算错误

发布于 2024-09-15 14:37:39 字数 1365 浏览 14 评论 0原文

我目前正在使用模拟器将我的旧应用程序调整为 iPhone 4，我可以通过 UILabel 绘图和 sizeWithFont:constrainedToSize: 遇到非常奇怪的行为，我目前仅在 iPhone 4 模拟器上看到。

我试图向用户显示以下错误文本： @“用户名或密码错误” 该文本位于一个动态错误框内，该框由三个部分组成：顶部、中心和底部，因此我计算标签的大小，以便可以相应地更改中心背景图像框架。

下面是 UILabel 大小计算代码的示例：

CGRect errorFrame = CGRectMake(40, 0, 240.0, 22.0);
UILabel *errorlabel = [[UILabel alloc] initWithFrame:errorFrame];
errorlabel.adjustsFontSizeToFitWidth = NO;
errorlabel.font = [UIFont fontWithName:@"HelveticaNeue" size:16];
errorlabel.textAlignment = UITextAlignmentLeft;
errorlabel.numberOfLines = 0;
errorlabel.text = @"Incorrect user name or password";
// since only the width is fixed I will use a really large height value
CGSize errorLabelSize = [errorlabel.text sizeWithFont:errorlabel.font constrainedToSize:CGSizeMake(240.0, 4600.0)];
CGRect newFrame = errorlabel.frame;
newFrame.size.height = errorLabelSize.height;
errorlabel.frame = newFrame;
    // added so I can easily see the new frame
errorlabel.backgroundColor = [UIColor redColor];
[self.errorView addSubview:errorlabel];
[errorlabel release];

当我在 iPhone 3 模拟器上运行代码时，sizeWithFont:constrainedToSize: 方法返回 1 行的高度，并在 1 行上绘制此错误文本。当我在 iPhone 4 模拟器上运行相同的代码时， sizeWithFont:constrainedToSize: 返回两行所需的大小 (170.0, 42.0)，但标签本身绘制在 1 行上。就好像 sizeWithFont 代码不使用与渲染代码相同的逻辑。

由于无法更改错误文本:) 知道如何绕过此问题或解决它吗？

提前致谢

原文

I am adjusting my old apps to iPhone 4 using the simulator at the moment and I can across a very strange behavior with UILabel drawing and sizeWithFont:constrainedToSize: that I currently see only on the iPhone 4 simulator.

I am trying to show the following error text to the user:
@"Incorrect user name or password"
This text sits inside a dynamic error box that is built from three parts: top, center and bottom and therefore I calculate the size of the label so I can change the center background image frame accordingly.

Here is an example of the UILabel size calculation code:

CGRect errorFrame = CGRectMake(40, 0, 240.0, 22.0);
UILabel *errorlabel = [[UILabel alloc] initWithFrame:errorFrame];
errorlabel.adjustsFontSizeToFitWidth = NO;
errorlabel.font = [UIFont fontWithName:@"HelveticaNeue" size:16];
errorlabel.textAlignment = UITextAlignmentLeft;
errorlabel.numberOfLines = 0;
errorlabel.text = @"Incorrect user name or password";
// since only the width is fixed I will use a really large height value
CGSize errorLabelSize = [errorlabel.text sizeWithFont:errorlabel.font constrainedToSize:CGSizeMake(240.0, 4600.0)];
CGRect newFrame = errorlabel.frame;
newFrame.size.height = errorLabelSize.height;
errorlabel.frame = newFrame;
    // added so I can easily see the new frame
errorlabel.backgroundColor = [UIColor redColor];
[self.errorView addSubview:errorlabel];
[errorlabel release];

When I run the code on the iPhone 3 simulator the sizeWithFont:constrainedToSize: method returns a height of 1 line and draws this error text on 1 line.
When I run the same code on the iPhone 4 simulator sizeWithFont:constrainedToSize: returns a size of (170.0, 42.0) which is needed for two lines but label itself is drawn on 1 line.
It is as if the sizeWithFont code doesn't use the same logics of the rendering code.

Since changing the error text is no option :) any idea how to bypass this issue or resolve it?

Thanks in advance

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