在ios开发中使用 try 和 catch 来捕获错误。

//如果返回的报文是错误信息，则抛出错误
if([outParams count] <= 0)
{
[NSException raise:@"WebService error" format:@"%@", returnJson4SOAP];
}

//从soap 信息中解析出CusotmerDetail 对象
@try
{
customerDetail = [[[SoapRtnJsonParser alloc] init] parse2CustomerDtail:[returnSoapXML dataUsingEncoding:NSUTF8StringEncoding]];
}@catch (NSException * e) {
NSLog(@"Exception: %@", e);
UIAlertView * alert =
[[UIAlertView alloc]
initWithTitle:@"错误"
message: [[NSString alloc] initWithFormat:@"%@",e]
delegate:self
cancelButtonTitle:nil
otherButtonTitles:@"OK", nil];
[alert show];
[alert release];
return;
}