创建UIButton
UIButton *button = [[UIButton alloc] init];
button.frame = CGRectMake(50, 200, 200, 50);
[button setTitle:@"我是UIButton" forState:UIControlStateNormal];
[button setTitleColor:[UIColor blueColor] forState:UIControlStateNormal];
[button setBackgroundColor:[UIColor orangeColor]];
button.titleLabel.textAlignment = NSTextAlignmentLeft;
button.contentHorizontalAlignment = UIControlContentHorizontalAlignmentLeft;
[self.view addSubview:button];
创建一个button，让button的title居左，以便观察：
button1 (1).png
UIButton的contentEdgeInsets属性
@property(nonatomic) UIEdgeInsets contentEdgeInsets UI_APPEARANCE_SELECTOR; // default is UIEdgeInsetsZero
contentEdgeInsets里有一个content应该指的就是UIButton的title。
参数含义
上一篇文章我们讲了UIEdgeInsets是个结构体类型。里面有四个参数，分别是：top, left, bottom, right。这四个参数表示距离上边界、左边界、下边界、右边界的距离。
这四个参数的值可以为正值，也可以为负值。拿left举例：
left = 10; //代表以当前位置为基准，向右移动10个像素
left = -10; //代表以当前位置为基准，向左移动10个像素
top = 10; //代表以当前位置为基准，向下移动10个像素
top = -10; //代表以当前位置为基准，向上移动10个像素
向右移动20个像素
button.contentEdgeInsets = UIEdgeInsetsMake(0, 20, 0, 0);
Paste_Image.png
向左移动20个像素
button.contentEdgeInsets = UIEdgeInsetsMake(0, -20, 0, 0);
Paste_Image.png
UIButton的titleEdgeInsets属性
titleEdgeInsets和contentEdgeInsets的作用差不多。我们及设置contentEdgeInsets，又设置titleEdgeInsets，会怎样呢？
button.titleEdgeInsets = UIEdgeInsetsMake(0, 20, 0, 0);
button.contentEdgeInsets = UIEdgeInsetsMake(0, 20 , 0, 0);
看一下效果：
3
UIButton的imageEdgeInsets属性
创建一个带照片的button
UIButton *button = [[UIButton alloc] init];
button.frame = CGRectMake(50, 200, 200, 200);
[button setTitleColor:[UIColor blueColor] forState:UIControlStateNormal];
[button setBackgroundColor:[UIColor orangeColor]];
[button setImage:[UIImage imageNamed:@"test"] forState:UIControlStateNormal];
[self.view addSubview:button];
运行一下：
Paste_Image.png
向右移动50个像素
button.imageEdgeInsets = UIEdgeInsetsMake(0, 50, 0, 0);
看看效果：
Paste_Image.png
向左移动50个像素
button.imageEdgeInsets = UIEdgeInsetsMake(0, -50, 0, 0);
看看效果：
Paste_Image.png
