如何在 iPhone 中单击按钮时调用 url

Question

当用户使用此方法单击按钮时，我正在传递一个 URL，但我的应用程序崩溃了，我不知道我做错了什么。

我已经在另一个控制器中编写了这段代码（处理连接的代码），该控制器是从第一个视图中的按钮事件调用的。

特别是，这行代码：

NSURLRequest *theRequest=[NSURLRequest requestWithURL:[NSURL URLWithString:url]cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0];

产生以下错误：

/Users/pradeepyadav/Desktop/RegexKitLiteDemo/Classes/SearchView.m:19:0 /Users/pradeepyadav/Desktop/RegexKitLiteDemo/Classes/SearchView.m:19：警告：不兼容的 Objective-C 类型“struct NSURL *” ，当从不同的 Objective-C 类型传递“URLWithString:”的参数 1 时，预期为“struct NSString *”

这是完整的代码：

- (void)LoadAirport

{    
    NSString *urlString = [NSString stringWithFormat:@"http://www.bookryanair.com/SkySales/FRSearch.aspx?AvailabilitySearchInputFRSearchView%24ButtonSubmit=Search%20For%20Flights%20&AvailabilitySearchInputFRSearchView%24DropDownListMarketDay1=<%i>&AvailabilitySearchInputFRSearchView%24DropDownListMarketDay2=<%i>&AvailabilitySearchInputFRSearchView%24DropDownListMarketDestination1=<%@>&AvailabilitySearchInputFRSearchView%24DropDownListMarketMonth1=<%i>&AvailabilitySearchInputFRSearchView%24DropDownListMarketMonth2=<%i>&AvailabilitySearchInputFRSearchView%24DropDownListMarketOrigin1=<%@>&AvailabilitySearchInputFRSearchView%24DropDownListPassengerType_ADT=1&AvailabilitySearchInputFRSearchView%24DropDownListPassengerType_CHD=0&AvailabilitySearchInputFRSearchView%24DropDownListPassengerType_INFANT=0&AvailabilitySearchInputFRSearchView%24RadioButtonFlowSelector=FlightAndCar&AvailabilitySearchInputFRSearchView%24RadioButtonMarketStructure=RoundTrip&AvailabilitySearchInputFRSearchView%24discountPax=0&__EVENTARGUMENT=&__EVENTTARGET=&__VIEWSTATE=%2FwEPDwUBMGRkg4UKvNNb1NbM14%2F2n9zUxhNQ%2B%2BA%3D&errorlist=",day,day1,DestinCode,fromDate1,fromDate2,OriginCode];
    NSURL *url = [NSURL URLWithString:urlString];
    NSURLRequest *theRequest=[NSURLRequest requestWithURL:[NSURL URLWithString:url]cachePolicy:NSURLRequestUseProtocolCachePolicy
                                          timeoutInterval:60.0];
    NSURLConnection *theConnection=[[NSURLConnection alloc] initWithRequest:theRequest delegate:self];
    if (theConnection) {
        webData = [[NSMutableData data] retain];
        NSLog(@"%@",webData);
    } else {

    }
}

- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response 
{
    //responseData = [[NSMutableData alloc] init];
    [webData setLength: 0]; 
}

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data 
{
    //[responseData appendData:data];
    [webData appendData:data]; 
}

- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error 
{
    [connection release];
    [webData release]; 
    NSLog(@"Connection failed! Error - %@ %@",
          [error localizedDescription],
          [[error userInfo] objectForKey:NSURLErrorFailingURLStringErrorKey]);
    //[textView setString:@"Unable to fetch data"];
}

- (void)connectionDidFinishLoading:(NSURLConnection *)connection 
{
    loginStatus = [[NSString alloc] initWithBytes: [webData mutableBytes] length:[webData length] encoding:NSUTF8StringEncoding]; 
    [connection release];
}

Answer 1

我确信错误是由于注意力不集中而发生的；-) 您正在传递一个 NSURL 实例作为参数，而您应该在其中传递一个 NSString。

就行了，

NSURLRequest *theRequest = [NSURLRequest requestWithURL:...

要么设置，

requestWithURL:url

要么，

requestWithURL:[NSURL URLWithString:urlString];

Answer 2

将此代码用于 NSURLRequest。

NSMutableURLRequest *theRequest = [NSMutableURLRequest requestWithURL:url];