iOS：接收崩溃NSInvalidArgumentException NSConcreteMutableAttributedString addAttribute：value：range :: nil value

Question

这是发生错误的行。

 [self addAttribute:(__bridge NSString*)kCTForegroundColorAttributeName value:(__bridge id)color.CGColor range:range];

这是完整的方法代码。

 -(void)setTextColor:(UIColor*)color range:(NSRange)range
 {
if (range.location != NSNotFound) {
// kCTForegroundColorAttributeName
[self removeAttribute:(__bridge NSString*)kCTForegroundColorAttributeName range:range]; // Work around for Apple leak
[self addAttribute:(__bridge NSString*)kCTForegroundColorAttributeName value:(__bridge id)color.CGColor range:range];
   }}

我尝试测试是否找不到范围，但错误仍然存​​在。关于我做错了什么的提示或建议？

Answer 1

这是因为(__bridge id)color.CGColor是nil 就这样做，没有任何额外的转换

[self addAttribute:NSForegroundColorAttributeName value:color range:range];

Answer 2

错误地检查你的情况，你需要：

if (range.location >= 0 && range.location < self.length){
    if (range.location + range.length >= self.length)
        range.length = self.length - range.location;

    [self removeAttribute:(__bridge NSString*)kCTForegroundColorAttributeName range:range]; // Work around for Apple leak
    [self addAttribute:(__bridge NSString*)kCTForegroundColorAttributeName value:(__bridge id)color.CGColor range:range];
}