iOS 从代码 : can't control UIButton titlebar text alignment 添加 UIButton

Question

我在 UIView 中添加了一个 UIButton，

    UIButton *switchButtonL = [UIButton buttonWithType: UIButtonTypeSystem];
    [switchButtonL addTarget:self action:@selector(switchCity:) forControlEvents:UIControlEventTouchUpInside];
    switchButtonL.frame =  CGRectMake(0, 50, self.screenWidth/2, 30);
    [switchButtonL setTitle: NSLocalizedString(@"switchcity", nil) forState:UIControlStateNormal];
    [switchButtonL setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
    [switchButtonL setTitleColor:[UIColor blueColor] forState:UIControlStateSelected];
    [switchButtonL setBackgroundColor:[UIColor clearColor] ];
    switchButtonL.titleLabel.textAlignment = NSTextAlignmentLeft; // this line can't work
    switchButtonL.titleLabel.font = [UIFont fontWithName:@"HelveticaNeue-Light" size:18];
    [self addSubview:switchButtonL];

并且注释行不起作用，文本总是居中对齐。

Answer 1

尝试替代

switchButtonL.titleLabel.textAlignment = NSTextAlignmentLeft; // this line can't work

与:

switchButtonL.contentHorizontalAlignment = UIControlContentHorizontalAlignmentLeft;
switchButtonL.contentEdgeInsets = UIEdgeInsetsMake(0, 10, 0, 0);