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如何在nsxmlparser运行时禁用按钮,然后在完成时启用它?

cocoa-touch cocoa iphone

conorgriffin · 技术社区 · 15 年前

我有一个 viewController 哪些进口 XMLParser.h 作为班级 xmlParser

我路过一个 NSURL 我的对象 可视控制器 到 XML分析器 类与 getXML 方法如下

goButton 我按的按钮是呼叫 获取XML 方法如下。我禁用了我点击触发的按钮 获取XML 方法,但我不确定在XML解析器完成对返回的XML的解析后,将代码放在何处再次启用它。

- (IBAction) getXML {
    goButton.enabled = NO;

    // allocate and initialize the xmlParser 
    xmlParser = [[XMLParser alloc] init];

// then generate the URL we are going to pass to it and call the fetchXML method passing the URL.
    NSURL *xmlurl = [[NSURL alloc] initWithString:@"http://www.mysite.com/myfile.xml"];
    [xmlParser fetchXMLFromURL:xmlurl];

    // release objects
    [xmlurl release];
    [xmlParser release];

}

根据@squegy的建议,我修改了我的代码。

- (IBAction) getXML {
    goButton.enabled = NO;

    xmlParser = [[XMLParser alloc] init];

    [self performSelectorInBackground:@selector(parseInBackground:) withObject:xmlParser];

}

- (void)parseInBackground:(XMLParser*)parser {
    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];

    NSURL *xmlurl = [[NSURL alloc] initWithString:@"http://www.mysite.com/myfile.xml"];

    [parser fetchXMLFromURL:xmlurl];
    [self performSelectorOnMainThread:@selector(didFinishXMLParsing:) withObject:parser];

    [xmlurl release];
    [pool drain];

}

- (void)didFinishXMLParsing:(NSXMLParser*)parser {
    goButton.enabled = YES;
}

在到达生产线之前看起来一直在工作

[self performSelectorOnMainThread:@selector(didFinishXMLParsing:) withObject:parser];

编译器的投诉如下:

2010-02-17 00:22:20.574 XMLApp[2443:521b] *** -[viewController performSelectorOnMainThread:withObject:]: unrecognized selector sent to instance 0x1285a0
2010-02-17 00:22:20.578 XMLApp[2443:521b] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[viewController performSelectorOnMainThread:withObject:]: unrecognized selector sent to instance 0x1285a0'
2010-02-17 00:22:20.583 XMLApp[2443:521b] Stack: (
    861696817,
    860329709,
    861700631,
    861203093,
    861166272,
    18715,
    846004025,
    845672609,
    848189713
)

2 回复 | 直到 15 年前

Alex Wayne 15 年前

- (IBAction)getXML {
    goButton.enabled = NO;

    xmlParser = [[XMLParser alloc] init];
    NSURL *xmlurl = [[NSURL alloc] initWithString:@"http://www.mysite.com/myfile.xml"];
    [xmlParser fetchXMLFromURL:xmlurl];

    [self performSelectorInBackground:@selector(parseInBackground) withObject:xmlParser];

    [xmlurl release];
    [xmlParser release];
}

- (void)parseInBackground:(NSXMLParser*)parser {
    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];

    [parser parse];
    [self performSelectorOnMainThread:@selector(didFinishXMLParsing:)
                           withObject:parser
                        waitUntilDone:NO];

    [pool drain];
}

- (void)didFinishXMLParsing:(NSXMLParser*)parser {
    goButton.enabled = YES;
}

-1

pgb 15 年前

- (void)parserDidEndDocument:(NSXMLParser *)parser

performSelectorInMainThread