項(xiàng)目開發(fā)中，使用UITextView 設(shè)置系統(tǒng)私有屬性_placeholderLabel，8.1.3版本出現(xiàn)崩潰，特別為此進(jìn)行版本支持測(cè)試，最后結(jié)果_placeholderLabel，支持版本為8.3

UIAlertController 中的 UIAlertAction 設(shè)置按鈕的文字顏色"TitleTextColor" 支持版本為8.3

@interface UITextView (TXPlaceholder)

/**
 設(shè)置textView placeholder

 @param text 文字
 @param textColor 顏色
 @param font 字體
 */
- (void)addPlaceholderWithText:(NSString *)text
                     textColor:(UIColor *)textColor
                          font:(UIFont *)font;

@end

@implementation UITextView (TXPlaceholder)

/**
 設(shè)置textView placeholder
 
 @param text 文字
 @param textColor 顏色
 @param font 字體
 */
- (void)addPlaceholderWithText:(NSString *)text
                     textColor:(UIColor *)textColor
                          font:(UIFont *)font {
    UILabel *placeHolderLabel = [[UILabel alloc] init];
    placeHolderLabel.text = text;
    placeHolderLabel.numberOfLines = 0;
    placeHolderLabel.textColor = textColor;
    [placeHolderLabel sizeToFit];
    [self addSubview:placeHolderLabel];
    // same font
    placeHolderLabel.font = font;

    if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 8.3) {
        [self setValue:placeHolderLabel forKey:@"_placeholderLabel"];
    }
}

@end

/**
 設(shè)置alert按鈕顏色
 
 @param color
 @param action
 */
+ (void)setActionTitleTextColor:(UIColor *)color action:(UIAlertAction *)action {
    if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 8.3) {
        [action setValue:color forKey:@"titleTextColor"];
    }
}