毫无例外地在[textView insertText:]上停止执行！ [英] execution stops on [textView insertText:] without exception!

问题描述

我正在编写一个非常简单的OSX应用程序.在此应用程序中，有一个主线程不断更新某些内容，然后计算一些统计信息并将其打印在textView上.

I am writing a very simple OSX app. In this app, there is a main thread that keeps updating some stuff, then calculates some statistics and prints them on a textView.

在开发过程中，我使用了相同的接收到的IBAction来执行此循环.我一切正常，然后切换到NSThread以防止UI在计算时锁定.

While developing, i used the same received IBAction to perform this cycle. I got it all working, then switched to NSThread to prevent the UI from locking while computing.

我这样做之后，该应用程序开始运行很少的周期(大约7-8)，然后整个应用程序冻结，没有任何异常.通过调试，我注意到在尝试在textView上打印统计信息时，它冻结了，我对如何解决此问题一无所知.如果不在线程内，它就可以工作...有人可以帮忙吗?下面的代码.在此先感谢:)

As soon as i did that, the app started running very few cycles (about 7-8), then the whole app freezes without any exception. By debugging, i noticed that it freezes when trying to print statistics on the textView, and i have absolutely no clue about how to solve this. It works if not inside a thread... Anyone can help? Code below. Thanks in advance :)

-(IBAction) Evolve:(id)sender{
 NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
 [NSThread detachNewThreadSelector:@selector(Evolve) toTarget:self withObject:nil];
 [pool drain];
}

这是整个周期

-(void) Evolve{

    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];

    srandom(time(NULL));

    //Tag 0: Minimo, Tag 1: Massimo
    int tagMinMax = [MinMax selectedTag];

    //Tag 0: Rimpiazza sempre, Tag 1: Rimpiazza solo se migliori
    int tagRimpiazzo = [[Rimpiazzo selectedItem] tag];

    int PopNum = [tf_popNum intValue];
    int maxGen = [tf_maxGen intValue];
    int target = [tf_targetVal intValue];
    int chromosomeLength = [tf_chromosomeLength intValue];

    Environment *env = [[Environment alloc] init];

    NSMutableArray *pop = [[NSMutableArray alloc] init];
    for (int i = 0; i < PopNum; i++) {
        [pop addObject:[[Individual alloc] initWithRandomGenesWithChromosomeLength:chromosomeLength]];
    }

    [env setPopulation:pop];
    [pop release];

    BOOL earlyBestFound = NO;
    Individual *earlyBest = nil;
    int i=0;
    float best, avg;
    while (i<maxGen && !earlyBestFound) {
        NSLog(@"while");
        NSArray *parents = [env selectParents];
        NSLog(@"parents selected");
        NSMutableArray *offspring = [[NSMutableArray alloc] init];
        for (int i = 0; i < [parents count]; i+=2) {
            if (i+1<[parents count]) {
                NSLog(@"beginning SEX");
                Individual *parent1 = [parents objectAtIndex:i];
                Individual *parent2 = [parents objectAtIndex:i+1];

                NSArray *children = [parent1 kCrossOverWithOtherIndividual:1 individual:parent2];

                Individual *child1 = [children objectAtIndex:0];
                Individual *child2 = [children objectAtIndex:1];

                NSLog(@"children born");

                if (tagRimpiazzo!=0) {
                    if (([child1 fitness] > [parent1 fitness] && tagMinMax == 0)||([child1 fitness] < [parent1 fitness] && tagMinMax == 1)) {
                        child1 = parent1;
                    }
                    if (([child2 fitness] > [parent2 fitness] && tagMinMax == 0)||([child2 fitness] < [parent2 fitness] && tagMinMax == 1)) {
                        child2 = parent2;
                    }
                }

                NSLog(@"Replacement happened");

                [offspring addObject:child1];
                [offspring addObject:child2];
            }
        }
        NSLog(@"Calculating statistics");
        avg = 0;
        for(Individual *X in offspring){

            if (([X fitness] > best && tagMinMax == 1)||([X fitness] < best && tagMinMax == 0)) {
                best = [X fitness];
            }

            avg += [X fitness];

            if ([X fitness]==target) {
                earlyBestFound = YES;
                earlyBest = X;
            }
        }
        avg = avg/(float)PopNum;

        [env setPopulation:offspring];

        NSLog(@"Releasing some memory");

        [offspring release];

        NSLog(@"Printing statistics");
        NSString *toPrint = [NSString stringWithFormat:@"Fine generazione: %d avg: %.2f best: %.2f \r\n", i,avg,best];
        [textView insertText:toPrint];

        i++;
    }

    NSLog(@"Fine");

    NSString *toPrint = [NSString stringWithFormat:@"Fine! best: %.2f - avg: %.2f \r\n", i,avg,best];
    [textView insertText:toPrint];

    [env release];

    [pool drain];
}

P.S.抱歉，如果英语不够完美，我是意大利语:)

P.S. Sorry if the english's not perfect, i'm italian :)

推荐答案

您的应用程序崩溃了，因为您正在从后台线程访问 textView .UI对象只能从主线程访问.

Your application is crashing because you are accessing textView from a background thread. UI objects may only be accessed from the main thread.

要解决此问题，您需要将 textview 更新转发到主 UI 线程.您可以使用 -performSelectorOnMainThread:方法执行此操作.例如:

To solve the problem, you will need to forward you textview updates to the main UI thread. You can do this using the -performSelectorOnMainThread: method. For example:

[textView performSelectorOnMainThread:@selector(insertText:) 
                           withObject:toPrint 
                        waitUntilDone:YES];

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