Question

我使用下面的代码来解析在线XML文件。当我运行应用程序时，我的文本字段是空的。如何从NSXMLParser中提取字符串并将它们放入IBOutlet，如文本字段，菜单项或标签？

接口文件：

#import <Foundation/Foundation.h>

@interface XMLCurrent : NSObject <NSXMLParserDelegate> {
    IBOutlet NSTextField *location;
    IBOutlet NSTextField *condition;
    IBOutlet NSTextField *degreesF;

    NSMutableString *xmlLocation;
    NSMutableString *xmlWeather;
    NSMutableString *xmlTempF;
}

- (void)fetchCurrentWeather:(id)sender;

@end

实施档案：

#import "XMLCurrent.h"

@implementation XMLCurrent

- (void)fetchCurrentWeather:(id)sender {

    NSURL *xmlURL = [NSURL URLWithString:@"http://www.weather.gov/xml/current_obs/KCLT.xml"];

    NSXMLParser *parser = [[NSXMLParser alloc] initWithContentsOfURL:xmlURL];
    [parser setDelegate:self];
    [parser parse];
}

- (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary *)attributeDict {

    if ([elementName isEqual:@"location"]) {
        xmlLocation = [[NSMutableString alloc] init];
    }

    if ([elementName isEqual:@"weather"]) {
        xmlWeather = [[NSMutableString alloc] init];
    }

    if ([elementName isEqual:@"temp_f"]) {
        xmlTempF = [[NSMutableString alloc] init];
    }
}

- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string {

    [xmlLocation appendString:string];
    [xmlWeather appendString:string];
    [xmlTempF appendString:string];
}

- (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName {

    if ([elementName isEqual:@"location"]) {
        [location setStringValue:xmlLocation];
    }

    if ([elementName isEqual:@"weather"]) {
        [condition setStringValue:xmlWeather];
    }

    if ([elementName isEqual:@"temp_f"]) {
        [degreesF setStringValue:xmlTempF];
    }
}

@end

Answer 1

我认为您的问题可能有两个原因：

您在调用viewDidLoad之前解析XML，这就是为什么所有商店都是零的
您没有在Interface Builder中连接它们。

无法将NSXMLParser数据导入文本字段，菜单项或标签

1 个答案: