如何将 UIButton 的标题设置为左对齐？

I need to display the email address from left side of a UIButton, but it is being positioned in the centre.

Is there any way to set the alignment to the left side of a UIButton?

This is my current code:

UIButton* emailBtn = [[UIButton alloc] initWithFrame:CGRectMake(5,30,250,height+15)];
emailBtn.backgroundColor = [UIColor clearColor];
[emailBtn setTitle:obj2.customerEmail forState:UIControlStateNormal];
emailBtn.titleLabel.font = [UIFont systemFontOfSize:12.5];
[emailBtn setTitleColor:[[[UIColor alloc]initWithRed:0.121 green:0.472 blue:0.823 alpha:1]autorelease] forState:UIControlStateNormal];
[emailBtn addTarget:self action:@selector(emailAction:) forControlEvents:UIControlEventTouchUpInside];
[elementView addSubview:emailBtn];
[emailBtn release];

Set the contentHorizontalAlignment:

emailBtn.contentHorizontalAlignment = UIControlContentHorizontalAlignmentLeft;

You might also want to adjust the content left inset otherwise the text will touch the left border:

emailBtn.contentEdgeInsets = UIEdgeInsetsMake(0, 10, 0, 0);

There is a small error in the code of @DyingCactus. Here is the correct solution to add an UILabel to an UIButton to align the button text to better control the button 'title':

NSString *myLabelText = @"Hello World";
UIButton *myButton = [UIButton buttonWithType:UIButtonTypeCustom];

// position in the parent view and set the size of the button
myButton.frame = CGRectMake(myX, myY, myWidth, myHeight); 

CGRect myButtonRect = myButton.bounds;
UILabel *myLabel = [[UILabel alloc] initWithFrame: myButtonRect];   
myLabel.text = myLabelText;
myLabel.backgroundColor = [UIColor clearColor];
myLabel.textColor = [UIColor redColor]; 
myLabel.font = [UIFont fontWithName:@"Helvetica Neue" size:14.0];   
myLabel.textAlignment = UITextAlignmentLeft;

[myButton addSubview:myLabel];
[myLabel release];

Hope this helps....

Al

Here is explained how to do it and why it works so: http://cocoathings.blogspot.com/2013/03/how-to-make-uibutton-text-left-or-right.html

Using emailBtn.titleEdgeInsets is better than contentEdgeInsets, in case you don't want to change the whole content position inside the button.

You can also use interface builder if you don't want to make the adjustments in code. Here I left align the text and also indent it some:

Don't forget you can also align an image in the button too.:

UIButton *btn;
btn.contentVerticalAlignment = UIControlContentVerticalAlignmentTop;
btn.contentHorizontalAlignment = UIControlContentHorizontalAlignmentLeft;

In Swift 3+:

button.contentHorizontalAlignment = .left

For Swift 2.0:

emailBtn.contentHorizontalAlignment = UIControlContentHorizontalAlignment.Left  

This can help if any one needed.

in xcode 8.2.1 in the interface builder it moves to:

Swift 4+

button.contentHorizontalAlignment = .left
button.contentVerticalAlignment = .top
button.contentEdgeInsets = UIEdgeInsets(top: 10, left: 10, bottom: 10, right: 10)