从从php检索的值设置UILabel文本

Question

I need to automatically get a variable from an existing php file to replace the text of a label when the view controller changes. The change of view controller happens with the push of a button (if this is relevant?) I already made the database on our hosting, and the variables are in place.

1) I need to know how to adress the automation problem
2) I need to know how to get the variable from the php file

Answer 1

Your PHP should return the contents in the variable in a format easily consumed by your Objective-C program, for example JSON. So, for example,

<?php

// retrieve the value of $result variable any way you want. I'm going to just set the literal

$result = "Hello World!"; 

// now convert to an array

$result_array = array("result" => $result);

// return the json_encoded rendition

echo json_encode($result_array);

?>

That will end up returning a result that looks like:

{"result":"Hello World!"}

Now, that JSON can be consumed by your Objective-C code, e.g.:

NSURL *url = [NSURL URLWithString:@"..."]; // put your URL in here
NSURLRequest *request = [NSURLRequest requestWithURL:url];
NSOperationQueue *queue = [[NSOperationQueue alloc] init];
[NSURLConnection sendAsynchronousRequest:request queue:queue completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {

    // make sure there wasn't a connection error

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

    // parse the JSON data

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

    // make sure there wasn't a JSON parsing error

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

    // now grab the "result" value from the dictionary we parsed from the JSON
    // make sure to do all UI stuff on the main queue, though

    [[NSOperationQueue mainQueue] addOperationWithBlock:^{
        self.label.text = jsonDictionary[@"result"];
    }];
}];