在我的应用程序中，我打算让两个（或更多）设备共享和合并 NSDictionaries。我的 Multipeer Connectivity 工作完美，当归结为在每次传输时合并两个字典时，我遇到了一个问题。我现在有两个“for”循环遍历两个字典。如果存在已经存在的键/值对，则会提示用户是否要覆盖已存在的对象或保留它。他们可以选择保留当前对象、覆盖当前对象、保留所有冲突对象或覆盖所有冲突对象。我到目前为止的代码：
-(void)session:(MCSession *)session didReceiveData:(NSData *)data fromPeer:(MCPeerID *)peerID{
pathChooser = 1;
NSLog(@"DATA RECEIVED: %d bytes!", data.length);
dataReceived = data;
receivedDataDict = [[NSMutableDictionary alloc] init];
receivedDataDict = [NSKeyedUnarchiver unarchiveObjectWithData:dataReceived];
for (key1 in receivedDataDict) {
NSLog(@"%@", key1);
if ([dataDict objectForKey:key1] == nil) {
NSLog(@"Writing new folder");
[dataDict setObject:[[NSMutableDictionary alloc] init] forKey:key1];
}
for (key2 in [receivedDataDict objectForKey:key1]) {
if ([[dataDict objectForKey:key1] objectForKey:key2] == nil) {
NSLog(@"Writing a new file");
[[dataDict objectForKey:key1] setObject:[[receivedDataDict objectForKey:key1] objectForKey:key2] forKey:key2];
}
else{
if (pathChooser == 1) {
NSLog(@"MADE IT TO -ALREADY EXISTS-");
UIAlertView *alert1 = [[UIAlertView alloc]initWithTitle: [[NSString alloc] initWithFormat:@"Match %@ already exists in %@!", key2, key1]
message: @"Overwrite?"
delegate: self
cancelButtonTitle:@"Keep"
otherButtonTitles:@"Overwrite", @"Keep All", @"Overwrite All",nil];
[alert1 show];
}
else if (pathChooser == 3){
NSLog(@"Path 3");
[[dataDict objectForKey:key1] setObject:[[receivedDataDict objectForKey:key1] objectForKey:key2] forKey:key2];
}
}
}
}
[dataDict writeToFile:path atomically:YES];
NSLog(@"%@", dataDict);
receivedDataDict = nil;
}
// Buttons for UIAlertView...
-(void)alertView:(UIAlertView *)alert1 clickedButtonAtIndex:(NSInteger)buttonIndex{
//Keep Current
if (buttonIndex == 0) {
pathChooser = 1;
}
//Overwrite Current
else if (buttonIndex == 1) {
[[dataDict objectForKey:key1] setObject:[[receivedDataDict objectForKey:key1] objectForKey:key2] forKey:key2];
}
//Keep All
else if (buttonIndex == 2) {
pathChooser = 2;
}
//Overwrite All
else if (buttonIndex == 3) {
pathChooser = 3;
}
}
当两个 NSDictionaries 之间存在多个相似的键/值对时，我遇到的问题会快速连续创建 UIAlertView 多次，这显然不是一件好事。有没有办法可以延迟 UIAlertView 的每次创建？还有比这更明显的解决方案吗？我尝试使用代码块，但代码块似乎没有读取“key1”和“key2”值，因为它们在 UIAlertView 中显示为“(null)”。我也在 [alert1 show] 之后的行中尝试了这种方法：
while ((!alert1.hidden) && (alert1.superview != nil))
{
[[NSRunLoop currentRunLoop] limitDateForMode:NSDefaultRunLoopMode];
}
但它似乎直到第二次创建 UIAlertView 之后才起作用。我得到的错误是：
-[UIKeyboardTaskQueue performTask:] 中的断言失败，/SourceCache/UIKit/UIKit-2903.23/Keyboard/UIKeyboardTaskQueue.m:388
由于未捕获的异常“NSInternalInconsistencyException”而终止应用程序，原因：“-[UIKeyboardTaskQueue performTask:] 只能从主线程调用。”
欢迎任何建议，我会尽力而为。我找不到很多和我有同样问题的人。