Question

我希望在我的应用中自动填充UITextFiled。在用户键入一些字母时，它将调用Web服务并在UIpPickerView中显示响应，以便搜索城市。当我们输入任何字母时，它会显示一些城市名称。谁能知道该怎么做？请帮我。

Answer 1

要以异步方式从服务器获取数据，您可以使用NSURLConnection和NSURLConnectionDelegate方法

在界面文件中：

@interface ViewController : UIViewController<NSURLConnectionDelegate, UITextFieldDelegate> {
    NSMutableData *mutableData;
}
-(void)getDataUsingText:(NSString *)text;
@end

在实施档案中：

@implementation ViewController
-(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
    NSString *value =[textField.text stringByReplacingCharactersInRange:range withString:string];
    [self getDataUsingText:value];
    return YES;
}


-(void)getDataUsingText:(NSString *)text;
{
    NSString *urlString = [NSString stringWithFormat:@"http://...."];
    NSURL *url =[NSURL URLWithString:urlString];
    NSURLRequest *request = [[NSURLRequest alloc] initWithURL:url];
    NSURLConnection *conn = [[NSURLConnection alloc] initWithRequest:request delegate:self];
    [conn start];
}


-(void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
    mutableData = [[NSMutableData alloc] init];
}

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


-(void)connectionDidFinishLoading:(NSURLConnection *)connection
{    
    NSString *dataString = [[NSString alloc] initWithData:mutableData encoding:NSUTF8StringEncoding];
    NSLog(@"your data from server: %@", dataString);
    // Here you got the data from server asynchronously.
    // Here you can parse the string and reload the picker view using [picker reloadAllComponents];

}
@end

您必须将委托设置为文本字段，并且必须使用NSURLConnectionDelegate方法中的数据实现选择器。 this是一个加载选择器视图的教程。

如何在iphone中使用异步Web服务调用自动完成TextField？

1 个答案: