Original article link: http://blog.devtang.com/2011/11/20/set-uilabel-text-align-top/
The default Uilabel is aligned vertically, and if your uilabel height has multiple lines, it will automatically center vertically when the content is low.
As shown (image from StackOverflow):
It is depressing that Uilabel does not provide the option to set its vertical alignment. So if you want to align the top of your text, you need to find a way to do it yourself. Several methods are available on the stackoverflow.com to achieve top-aligned effects.
Method One
When displaying text, first calculate how wide and how high the current text is displayed, and then change the size of the corresponding Uilabel to the corresponding width and height. The phase of this method is as follows:
When displaying text, first calculate how wide and how high the current text is displayed, and then change the size of the corresponding Uilabel to the corresponding width and height. The phase of this method is as follows:
Cgsize MaximumSize =Cgsizemake (300,9999); NSString *datestring =@ "The date today is January 1st, 1999"; Uifont *datefont = [uifont fontwithname:@ "Helvetica" size:14]; Cgsize datestringsize = [DateString Sizewithfont:datefont Constrainedtosize:maximumsize Linebreakmode:selfdatelabel. Linebreakmode]; CGRect dateframe = CGRectMake (Ten, ten, datestringsize. height); Self. Datelabel. frame = Dateframe;
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Method Two
This method is more simple and rude, but effective. The method is to add more \ n after the text.
It is important to note that after \ n is added at least one space, otherwise the extra \ n will be ignored by Uilabel. From this point of view, Uilabel seems to be too "smart".
The method is as follows:
The code for this method is as follows:
for (int i=0; i<newlinestopad; i++) Self. Text = [self. Text stringbyappendingstring:@ "\ n"];
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Method Three
The most orthodox method, using the OBJECTIVE-C category feature, modifies the Uilabel drawing code. The sample code is as follows:
--File:uilabel+verticalalign.h #pragma Mark VerticalAlign @interfaceUILabel (VerticalAlign) - (void) AlignTop; - (void) AlignBottom; @end
--FILE:UILABEL+VERTICALALIGN.M @implementationUILabel (VerticalAlign) - (void) AlignTop { Cgsize fontSize = [Self. Text Sizewithfont:Self. Font]; Double finalheight = fontSize. Height *Self. NumberOfLines; Double finalwidth =Self. Frame. Size. width;Expected width of label Cgsize thestringsize = [Self. Text Sizewithfont:Self. Font Constrainedtosize:Cgsizemake (Finalwidth, finalheight) Linebreakmode:Self. Linebreakmode]; int newlinestopad = (finalheight-thestringsize. Height)/fontSize. Height; Forint i=0; i<newlinestopad; i++) Self. Text = [Self. Text stringbyappendingstring:@ "\ n"]; }
- (void) AlignBottom { Cgsize fontSize = [Self. Text Sizewithfont:Self. Font]; Double finalheight = fontSize. Height *Self. NumberOfLines; Double finalwidth =Self. Frame. Size. width;Expected width of label Cgsize thestringsize = [Self. Text Sizewithfont:Self. Font constrainedtosize:cgsizemake (Finalwidth, Finalheight) Linebreakmode:self. Linebreakmode] ; int newlinestopad = (finalheight-thestringsize. Height)/fontSize. Height; For (int i=0; i<newlinestopad; i++) self. Text = [nsstring stringWithFormat:@ ' \n%@ ',self. text]; } @end
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I chose the simple method of violence two, what about you?
Resources
Http://stackoverflow.com/questions/1054558/how-do-i-vertically-align-text-within-a-uilabel
https://discussions.apple.com/thread/1759957?threadID=1759957
Align the top of the Uilabel text