将占位符文本居中在UITextField的子类中 [英] Centering Placeholder Text in Subclass of UITextField

问题描述

首先，我需要设置占位符文本颜色，因此我将UITextfield子类化为几个堆栈溢出帖子中显示的内容。这很好用。以下是此示例帖子：如何做我将UITextField子类化并覆盖drawPlaceholderInRect以更改占位符颜色。

So first, I needed to set the placeholder text color, so I subclassed the UITextfield as shown in several stack overflow posts. This works fine. Here is an example post of this: How do I subclass UITextField and override drawPlaceholderInRect to change Placeholder color.

但是，当我尝试使用 searchNameField.textAlignment = UITextAlignmentCenter; 它不再以占位符为中心。输入文本仍然处于中心位置。

But, when I try to use searchNameField.textAlignment = UITextAlignmentCenter; It is no longer centering the placeholder. The input text is still centered fine.

那么，假设由于子类化而使居中不起作用，我必须按顺序添加到我的UITextField子类中占位符文本居中？

So then, assuming that the centering is not working because of the subclassing, what do I have to add to my UITextField subclass in order to have the placeholder text centered?

谢谢

修改

这是我用来解决这个问题的代码。这是放在我的UITextField的子类中。

Here is the code I used to solve this problem. This is placed inside my subclass of UITextField.

- (CGRect)placeholderRectForBounds:(CGRect)bounds 
{
    CGSize size = [[self placeholder] sizeWithFont:[UIFont fontWithName:@"Arial" size:placeholdTextSize]];

    return CGRectMake( (bounds.size.width - size.width)/2 , bounds.origin.y , bounds.size.width , bounds.size.height);
}

请注意，placeholdTextSize是我在初始化期间设置的属性。

Note that placeholdTextSize is a property that I set during initialization.

推荐答案

这里你好伙伴

子类化UITextField将完成工作：

subclassing UITextField will do the work:

// CustomTextField.h
@interface CustomTextField : UITextField {
}
@end

覆盖方法：

@implementation
- (CGRect)placeholderRectForBounds:(CGRect)bounds {
    return CGRectMake(x,y,width,height);//Return your desired x,y position and width,height
}

- (void)drawPlaceholderInRect:(CGRect)rect {
    //draw place holder.
 [[self placeholder] drawInRect:rect withFont:[UIFont systemFontOfSize:12]];

}
@end

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