Question

我得到了与以下两个函数相关的大量EXC_BAD_ACCESS错误，用于读取和写入plist文件。我认为它的记忆力相关。有什么建议吗？

+(NSString *) getSettingString: (NSString *)key defaultValue:(NSString *)defValue
{
    NSArray *pathArray = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *path = [[pathArray objectAtIndex:0] stringByAppendingFormat:@"FSSettings_v3.plist"];
    [pathArray release];
    BOOL fileExists = [[NSFileManager defaultManager] fileExistsAtPath:path];
    if (fileExists == YES) {
        NSMutableDictionary* plistDictionary = [NSMutableDictionary dictionaryWithContentsOfFile:path];
        NSString *value =  [plistDictionary objectForKey:key];
        return value;
    } else {
        [self setSettingString:key value:defValue];
        return defValue;
    }

}

+(void) setSettingString: (NSString *)key value:(NSString *)value
{
    NSArray *pathArray = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *path = [[pathArray objectAtIndex:0] stringByAppendingFormat:@"FSSettings_v3.plist"];
    BOOL fileExists = [[NSFileManager defaultManager] fileExistsAtPath:path];
    if (fileExists == YES) {
        NSMutableDictionary* plistDictionary = [NSMutableDictionary dictionaryWithContentsOfFile:path];
        [plistDictionary setObject:value forKey:key];
        [plistDictionary writeToFile:path atomically:YES];
        [plistDictionary release];
    } else {
        NSMutableDictionary *dict = [[NSMutableDictionary alloc] init];
        [dict setObject:value forKey:key];
        [dict writeToFile:path atomically:YES];
        [dict release];
    }
    [pathArray release];
}

Answer 1

您不应该在第一种方法中发布pathArray：

NSArray *pathArray = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *path = [[pathArray objectAtIndex:0] stringByAppendingFormat:@"FSSettings_v3.plist"];
[pathArray release];

NSSearchNSSearchPathForDirectoriesInDomains返回一个自动释放的对象。始终在XCode中进行“构建和分析”。它会告诉你许多保留/释放问题。

那就是说，不要重新发明轮子。您可以使用NSUserDefaults。您的代码变为四行：

+(NSString *) settingString: (NSString *)key defaultValue:(NSString *)defValue
{
       NSString*v=[[NSUserDefaults standardUserDefaults] stringForKey:key];
       if(v){
             return v;
       }else{
             return defValue;
       }
}

+(void) setSettingString: (NSString *)key value:(NSString *)value
{
       [[NSUserDefaults standardUserDefaults] setObject:value forKey:key]
}

我会使用registerDefaults:向NSUserDefaults注册默认值，而不是将其提供给-getSettingString。

最后，您不应将get放在getter的名称中。这违背了Objective-C的习惯。在Objective-C中，get通常仅在通过作为方法参数传入的指针返回结果时使用，如-[NSData getBytes:length:]中所示。

EXC_BAD_ACCESS读取和写入plist文件

1 个答案: