Question

我创建了一个从普通字符串生成属性字符串的方法。下面的attrString值非空，且内容正确。

运行我的应用程序后，第二行失败并显示EXC_BAD_ACCESS。知道为什么吗？

__bridge_retained来电是iOS 5的要求。我也试过__bridge但是没有效果，问题仍然存在。

    NSMutableAttributedString *attrString = (NSMutableAttributedString*)[textLayer attributedString];
    CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString((__bridge_retained CFMutableAttributedStringRef)attrString);

更新

如果我这样做：

    NSMutableAttributedString *attrString = (NSMutableAttributedString*)[textLayer attributedString];
    NSLog(@"%@", attrString);
    CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString((__bridge CFMutableAttributedStringRef)attrString);

然后NSLog行不会编译; Xcode会发出警告和错误，说明"Incompatible pointer types passing 'char[3]' to parameter of type 'NSString *'"。

所以我尝试了这个：

    NSLog([attrString description]);

这会给出以下输出（我已将<snipped>的字符串内容替换为隐私）：

2012-01-19 06:49:11.307 WritePath[2475:707] <Snipped> { CTForegroundColor = "<CGColor 0x281530> [<CGColorSpace 0x22d1a0> (kCGColorSpaceDeviceRGB)] ( 0 0 0 1 )"; NSFont = "<CGFont (0x28f850): ArialMT>"; NSParagraphStyle = "CTParagraphStyle:\nwriting direction = -1, alignment = 3, line break mode = 0, default tab interval = 0\nfirst line head indent = 0, head indent = 0, tail indent = 0\nline height multiple = 0, maximum line height = 0, minimum line height = 0\nline spacing adjustment = 0, paragraph spacing = 0, paragraph spacing before = 0\ntabs:\n<CFArray 0x287b50 [0x3f229630]>{type = immutable, count = 12, values = (\n\t0 : CTTextTab: location = 28, alignment = 0, options = (none)\n\n\t1 : CTTextTab: location = 56, alignment = 0, options = (none)\n\n\t2 : CTTextTab: location = 84, alignment = 0, options = (none)\n\n\t3 : CTTextTab: location = 112, alignment = 0, options = (none)\n\n\t4 : CTTextTab: location = 140, alignment = 0, options = (none)\n\n\t5 : CTTextTab: location = 168, alignment = 0, options = (none)\n\n\t6 : CTTextTab: location = 196, alignment = 0, options = (none)\n\n\t7 : CTTextTab: location = 224, alignment = 0, options = (none)\n\n\t8 : CTTextTab: location = 252, alignment = 0, options = (none)\n\n\t9 : CTTextTab: location = 280, alignment = 0, options = (none)\n\n\t10 : CTTextTab: location = 308, alignment = 0, options = (none)\n\n\t11 : CTTextTab: location = 336, alignment = 0, options = (none)\n\n)}"; }

Answer 1

我在你的属性字符串转储中注意到了这一点：

NSFont = "<CGFont (0x28f850): ArialMT>"

您是否使用CGFontRef作为kCTFontAttributeName键的值创建了属性字符串？您必须使用CTFontRef，而不是CGFontRef。他们是不同的。

iOS：CTFramesetterCreateWithAttributedString导致EXC_BAD_ACCESS，任何猜测为什么？

1 个答案: