[iOS Dev] 簡單的網路連結測試 Simple Internet Connection test

2011年2月9日星期三

[iOS Dev] 簡單的網路連結測試 Simple Internet Connection test

以下範例為使用 NSURLConnection 測試網路連結

若網路連結失敗會回傳錯誤訊息 kCFURLErrorNotConnectedToInternet , 則使用UIAlertView來回報錯誤 (也可以做成Cancel and Retry讓使用者選擇)

若用 iPhone Simulator 是用Mac的網路連結, 所以測試前, 要先把Mac的網路斷線

若連結成功, 會在Console裡看到：

2011-02-09 15:28:38.148 ConnectionTest[11804:207] didReceiveResponse
2011-02-09 15:28:38.151 ConnectionTest[11804:207] didReceiveData
...
...
...
2011-02-09 15:28:38.965 ConnectionTest[11804:207] connectionDidFinishLoading

開始實作：先建立一個Template為Window-based Application 的 new project 叫 connectionTest

	//
	// ConnectionTestAppDelegate.h
	// ConnectionTest
	//
	// Created by Hank Wang on 2011/2/9.
	//

	#import <UIKit/UIKit.h>

	@interface ConnectionTestAppDelegate : NSObject <UIApplicationDelegate, UIAlertViewDelegate> {
	UIWindow *window;
	NSURLConnection *urlConnection;
	}

	- (void)startConnection;

	@property (nonatomic, retain) IBOutlet UIWindow *window;
	@property (nonatomic, retain) NSURLConnection *urlConnection;

	@end

view raw ConnectionTestAppDelegate.h hosted with ❤ by GitHub

	//
	// ConnectionTestAppDelegate.m
	// ConnectionTest
	//
	// Created by Hank Wang on 2011/2/9.
	//

	#import "ConnectionTestAppDelegate.h"

	@implementation ConnectionTestAppDelegate

	@synthesize window, urlConnection;


	- (BOOL)application:(UIApplication )application didFinishLaunchingWithOptions:(NSDictionary )launchOptions {
	[self.window makeKeyAndVisible];
	[self startConnection];
	return YES;
	}

	- (void)startConnection {
	// Connection Request
	NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:@"http://www.google.com"]];

	self.urlConnection = [[[NSURLConnection alloc] initWithRequest:request delegate:self] autorelease];

	[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;
	}

	// -------------
	// handleError:error
	// -------------
	- (void)handleError:(NSError *)error
	{
	NSString *errorMessage = [error localizedDescription];
	UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"Connect Test"
	message:errorMessage
	delegate:self
	cancelButtonTitle:@"Cancel"
	otherButtonTitles:@"Retry", nil];
	[alertView show];
	[alertView release];
	}


	// -------------
	// connection:didReceiveResponse:response
	// -------------
	- (void)connection:(NSURLConnection )connection didReceiveResponse:(NSURLResponse )response
	{
	NSLog(@"%@", @"didReceiveResponse");
	}


	// -------------
	// connection:didReceiveData:data
	// -------------
	- (void)connection:(NSURLConnection )connection didReceiveData:(NSData )data
	{
	NSLog(@"%@", @"didReceiveData");
	}


	// -------------
	// connection:didFailWithError:error
	// -------------
	- (void)connection:(NSURLConnection )connection didFailWithError:(NSError )error {
	NSLog(@"%@", @"didFailWithError");

	[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;

	if ([error code] == kCFURLErrorNotConnectedToInternet) {
	// if we can identify the error, we can present a more precise message to the user.
	NSDictionary *userInfo = [NSDictionary dictionaryWithObject:@"Connection Failed"
	forKey:NSLocalizedDescriptionKey];

	NSError *noConnectionError = [NSError errorWithDomain:NSCocoaErrorDomain
	code:kCFURLErrorNotConnectedToInternet
	userInfo:userInfo];
	[self handleError:noConnectionError];

	} else {

	// otherwise handle the error generically
	[self handleError:error];

	}

	self.urlConnection = nil; // release connection
	}


	// -------------
	// connectionDidFinishLoading:connection
	// -------------
	- (void)connectionDidFinishLoading:(NSURLConnection *)connection
	{
	self.urlConnection = nil; // release connection
	[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;

	// show successful
	UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"Connect Test"
	message:@"Connection Successful"
	delegate:nil
	cancelButtonTitle:@"OK"
	otherButtonTitles:nil];
	[alertView show];
	[alertView release];

	NSLog(@"%@", @"connectionDidFinishLoading");
	}


	// -----
	// alertView:alertView clickedButtonAtIndex:buttonIndex
	// -----
	- (void) alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex {
	switch (buttonIndex) {
	case 0:
	NSLog(@"Button Cancel Pressed");
	break;
	case 1:
	NSLog(@"Button Retry Pressed");
	[self startConnection];
	break;

	default:
	break;
	}
	}


	- (void)dealloc {
	[self.urlConnection release];
	[window release];
	[super dealloc];
	}

	@end