UITextField占位符字符串在ios7中始终是顶部对齐的

Question

我有UITextField类的子类并执行以下代码

- (void)drawPlaceholderInRect:(CGRect)rect
{

    [self.placeHolderTextColor setFill];
    [self.placeholder drawInRect:rect
                        withFont:self.placeHolderFont
                   lineBreakMode:NSLineBreakByTruncatingTail
                       alignment:NSTextAlignmentLeft];

}

我也写了 self.contentVerticalAlignment = UIControlContentVerticalAlignmentTop; 一行代码

此占位符文本在ios6中正确对齐,但在ios7中没有显示在顶部对齐.

虽然我输入的文本显示为居中.它只有占位符字符串的问题.

我已经尝试使用xib来设置占位符字符串.在XIB中它正确显示但是当我运行代码时,textfield占位符是顶部对齐的.

有什么解决方法吗？

Vadoff的回答对我有用.这仍然是完整的实现,可以帮助任何有同样问题的人.

drawInRect方法在ios7中已弃用并且drawInRectWithAttributes有效

- (void)drawPlaceholderInRect:(CGRect)rect
{

    [self.placeHolderTextColor setFill];

    CGRect placeholderRect = CGRectMake(rect.origin.x, (rect.size.height- self.placeHolderFont.pointSize)/2 - 2, rect.size.width, self.placeHolderFont.pointSize);
    rect = placeholderRect;

    if(iOS7) {

        NSMutableParagraphStyle* style = [[NSMutableParagraphStyle alloc] init];
        style.lineBreakMode = NSLineBreakByTruncatingTail;
        style.alignment = self.placeHolderTextAlignment;


        NSDictionary *attr = [NSDictionary dictionaryWithObjectsAndKeys:style,NSParagraphStyleAttributeName, self.placeHolderFont, NSFontAttributeName, self.placeHolderTextColor, NSForegroundColorAttributeName, nil];

        [self.placeholder drawInRect:rect withAttributes:attr];


    }
    else {
        [self.placeholder drawInRect:rect
                            withFont:self.placeHolderFont
                       lineBreakMode:NSLineBreakByTruncatingTail
                           alignment:self.placeHolderTextAlignment];
    }

}

Answer 1

drawInRect方法似乎在iOS7中表现不同,您可以尝试添加以下行并将其用作直接绘制的矩形.它也向后兼容iOS7之前的版本.

  CGRect placeholderRect = CGRectMake(rect.origin.x, (rect.size.height- self.font.pointSize)/2, rect.size.width, self.font.pointSize);