ios - 从剪贴板粘贴文本时自定义 NSTextStorage 崩溃
问题描述
我试图继承 NSTextStorage。现在,我只关注文档,覆盖原语:
class TextStorage: NSTextStorage {
private lazy var imp: NSTextStorage = NSTextStorage()
override var string: String {
imp.string
}
override func attributes(at location: Int, effectiveRange range: NSRangePointer?) -> [NSAttributedString.Key : Any] {
return imp.attributes(at: location, effectiveRange: range)
}
override func replaceCharacters(in range: NSRange, with str: String) {
imp.replaceCharacters(in: range, with: str)
edited(.editedCharacters, range: range, changeInLength: str.count - range.length)
}
override func setAttributes(_ attrs: [NSAttributedString.Key : Any]?, range: NSRange) {
imp.setAttributes(attrs, range: range)
edited(.editedAttributes, range: range, changeInLength: 0)
}
}
起初,一切正常。但是,当我尝试使用自定义的 TextStorage 将长文本(大约 9000 个字符)粘贴到 UITextView 时,我的应用程序崩溃了:
(lldb) thread backtrace
* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=2, address=0x16ee2c000)
* frame #0: 0x00000001f2a1364c libsystem_platform.dylib`_platform_memmove + 76
frame #1: 0x00000001a6efc910 CoreFoundation`CFStorageGetValues + 864
frame #2: 0x00000001a81daa5c Foundation`-[NSBigMutableString getCharacters:range:] + 168
frame #3: 0x00000001b024d724 UIFoundation`__NSGetClusterHeadWithLimit + 1024
frame #4: 0x00000001b024a29c UIFoundation`_NSFastFillAllGlyphHolesForCharacterRange + 756
我不认为 10k 对于 TextView 来说太大了,如果我使用默认的文本存储,它就可以正常工作。但我找不到问题出在哪里。
我尝试使用 Objective-C 而不是 Swift 来编写我的 TextStorage,但问题仍然存在:
#import "TextStorage.h"
@interface TextStorage ()
@property (nonatomic, strong) NSTextStorage *imp;
@end
@implementation TextStorage
- (NSString *)string
{
return self.imp.string;
}
- (NSDictionary<NSAttributedStringKey,id> *)attributesAtIndex:(NSUInteger)location effectiveRange:(NSRangePointer)range
{
return [self.imp attributesAtIndex:location effectiveRange:range];
}
- (void)replaceCharactersInRange:(NSRange)range withString:(NSString *)str
{
[self.imp replaceCharactersInRange:range withString:str];
[self edited:NSTextStorageEditedCharacters range:range changeInLength:str.length - range.length];
}
- (void)setAttributes:(NSDictionary<NSAttributedStringKey,id> *)attrs range:(NSRange)range
{
[self.imp setAttributes:attrs range:range];
[self edited:NSTextStorageEditedAttributes range:range changeInLength:0];
}
- (NSTextStorage *)imp
{
if (!_imp) {
_imp = [[NSTextStorage alloc] init];
}
return _imp;
}
@end
尝试添加beginEditing()
并endEditing()
喜欢这样,但它没有任何不同:
override func replaceCharacters(in range: NSRange, with str: String) {
beginEditing()
imp.replaceCharacters(in: range, with: str)
edited(.editedCharacters, range: range, changeInLength: str.count - range.length)
endEditing()
}
override func setAttributes(_ attrs: [NSAttributedString.Key : Any]?, range: NSRange) {
beginEditing()
imp.setAttributes(attrs, range: range)
edited(.editedAttributes, range: range, changeInLength: 0)
endEditing()
}
我发现崩溃是在 and 之后发生的replaceCharacters(in:with:)
,setAttributes(_:range:)
在processEditing()
调用下。但我没有覆盖processEditing()
.
解决方案
推荐阅读
- vue.js - TypeError:尝试记录我的 $refs 时无法读取未定义的属性“0”
- c++ - 在 Win32 应用程序中,如何检索应用程序类别信息
- katalon-studio - 如果 sql 查询返回正确的值,katalon 测试用例
- java - How to return the value of an asynchronous callback?
- javascript - Handling errors from forms - Node / Express
- java - Interface null pointer exception in Network Callback onAvailable method
- c# - Problem with huge numbers in an incremental game (C#, Unity)
- nestjs - process.env.NODE_ENV always 'development' when building nestjs app with nrwl nx
- jquery - Why isn't jQuery Number Counter updating on html attribute change?
- python - 为什么 python 抛出 ModuleNotFoundError: No module named `blah`