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我正在尝试我的第一个 xcode-project 从 php 文件中检索数据。我需要在 php 文件中检索的变量将是基于文本的。输出应该在我的项目中的标签或文本字段中输出。

我的编码有问题，需要一些帮助......

这是我的 php 文件的当前结构：

<?php
$idwlctxt = hello;
echo $idwlctxt;
?>

这是我到目前为止的编码。我试图从我发现的其他示例中编译它：

NSString *urlString = @"https://WEBSITE/test.php?";
NSData * dataURL = [NSData dataWithContentsOfURL:[NSURL URLWithString:urlString]];
NSString * result = [[NSString alloc] initWithData:dataURL encoding:NSUTF8StringEncoding];
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1 回答 1

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我认为您的 PHP 代码中缺少引号。您可能打算：

<?php
$idwlctxt = "hello";
echo $idwlctxt;
?>

此外，作为良好的防御性编程问题，您可能希望使用dataWithContentsOfURL为您检测错误的再现：

NSString *urlString = @"https://WEBSITE/test.php?";
NSError  *error     = nil;
NSData   *dataURL   = [NSData dataWithContentsOfURL:[NSURL URLWithString:urlString] options:kNilOptions error:&error];

if (error)
    NSLog(@"%s: dataWithContentsOfURL error: %@", __FUNCTION__, error);
else
{
    NSString *result = [[NSString alloc] initWithData:dataURL encoding:NSUTF8StringEncoding];
    NSLog(@"%s: result = %@", __FUNCTION__, result);

    // if you were updating a label with an `IBOutlet` called `resultLabel`, you'd do something like:

    self.resultLabel.text = result;
}

一旦你得到上面的代码，下一个逻辑增强就是使用 JSON（这是一种更好的将数据从 PHP 传递到 Objective-C 程序的技术）。PHP 代码如下所示：

<?php

$idwlctxt = "hello";

// As your PHP gets more complicated, you might want to handle errors and report
// them back to the client with a non-zero `status`, so I always return a status code.
// Clearly, this is so trivial that no error handling is needed, but it's a good
// habit to write your PHP with an eye on more extensive error handling in the future.

$response = array("status" => 0, "idwlctxt" => $idwlctxt);

echo json_encode($response);

// this should generate a response, something like:
//
//   {"status":0, "idwlctxt":"hello"}

?>

接下来，让我们解析这个 JSON 响应，并异步执行，这样我们就不会阻塞主队列：

NSString     *urlString = @"https://WEBSITE/test.php?";
NSURL        *url       = [NSURL URLWithString:urlString];

// rather than using `dataWithContentsOfURL`, let's use NSURLConnection to do an asynchronous request,
// so that the request doesn't block the main queue

// first, make the NSURLRequest

NSURLRequest *request   = [NSURLRequest requestWithURL:url];

// now, let's send that request asynchronously

[NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {

    // first, check to see if there was an error with sendAsynchronousRequest

    if (connectionError) {
        NSLog(@"%s: sendAsynchronousRequest error: %@", __FUNCTION__, connectionError);
        return;
    }

    // you generally don't do this conversion of the data to a string,
    // but it's useful to use this technique if you are diagnosing problems with your JSON
    //
    // NSString *jsonString = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
    // NSLog(@"%s: raw JSON = %@", __FUNCTION__, jsonString);

    // now, let's parse the JSON

    NSError *parseError = nil;
    NSDictionary *results = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:&parseError];

    if (parseError) {
        NSLog(@"%s: JSONObjectWithData error: %@", __FUNCTION__, parseError);
        return;
    }

    // now, let's extract our data from the JSON

    NSNumber *status   = results[@"status"];
    NSString *idwlctxt = results[@"idwlctxt"];
    NSLog(@"%s: status = %@; idwlctxt = %@", __FUNCTION__, status, idwlctxt);

    self.resultLabel.text = idwlctxt;
}];

还有其他可能的增强功能，但我担心我可能已经向你扔了太多东西，所以我会在这里停下来。

于 2013-09-24T21:31:02.220 回答