ios 学习笔记 7 之 protocol
object-c中的protocol有点类似于c#中的委托和接口，下面用实例来说明：
从远程下载图片到UIImage,然后再180度转换图片
View Code
#import <Foundation/Foundation.h>
#define TIMEOUT_SEC 20.0
@interface TSHttpClient : NSObject {
NSURLConnection *connection;
NSMutableData *recievedData;
int statusCode;
BOOL contentTypeIsXml;
int rate_limit;
int rate_limit_remaining;
NSDate *rate_limit_reset;
}
- (void)requestGET:(NSString*)url;
- (void)requestPOST:(NSString*)url body:(NSString*)body;
- (void)requestGET:(NSString*)url username:(NSString*)username password:(NSString*)password;
- (void)requestPOST:(NSString*)url body:(NSString*)body username:(NSString*)username password:(NSString*)password;
- (void)cancel;
- (void)requestSucceeded;
- (void)requestFailed:(NSError*)error;
- (void)reset;
@property (readonly) NSMutableData *recievedData;
@property (readonly) int statusCode;
@end
View Code
#import "TSHttpClient.h"
@implementation TSHttpClient
@synthesize recievedData, statusCode;
- (id)init {
if (self = [super init]) {
[self reset];
}
return self;
}
- (void)dealloc {
NSLog(@"NTLNHttpClient#dealloc");
[connection release];
[recievedData release];
[rate_limit_reset release];
[super dealloc];
}
+ (NSString*)stringEncodedWithBase64:(NSString*)str
{
static const char *tbl = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
const char *s = [str UTF8String];
int length = [str length];
char *tmp = malloc(length * 4 / 3 + 4);
int i = 0;
int n = 0;
char *p = tmp;
while (i < length) {
n = s[i++];
n *= 256;
if (i < length) n += s[i];
i++;
n *= 256;
if (i < length) n += s[i];
i++;
p[0] = tbl[((n & 0x00fc0000) >> 18)];
p[1] = tbl[((n & 0x0003f000) >> 12)];
p[2] = tbl[((n & 0x00000fc0) >> 6)];
p[3] = tbl[((n & 0x0000003f) >> 0)];
if (i > length) p[3] = '=';
if (i > length + 1) p[2] = '=';
p += 4;
}
*p = '\0';
NSString *ret = [NSString stringWithCString:tmp];
free(tmp);
return ret;
}
+ (NSString*) stringOfAuthorizationHeaderWithUsername:(NSString*)username password:(NSString*)password {
return [@"Basic " stringByAppendingString:[TSHttpClient stringEncodedWithBase64:
[NSString stringWithFormat:@"%@:%@", username, password]]];
}
- (NSMutableURLRequest*)makeRequest:(NSString*)url {
NSString *encodedUrl = (NSString*)CFURLCreateStringByAddingPercentEscapes(
NULL, (CFStringRef)url, NULL, NULL, kCFStringEncodingUTF8);
NSMutableURLRequest *request = [[[NSMutableURLRequest alloc] init] autorelease];
[request setURL:[NSURL URLWithString:encodedUrl]];
[request setCachePolicy:NSURLRequestReloadIgnoringLocalAndRemoteCacheData];
[request setTimeoutInterval:TIMEOUT_SEC];
[request setHTTPShouldHandleCookies:FALSE];
[encodedUrl release];
return request;
}
- (NSMutableURLRequest*)makeRequest:(NSString*)url username:(NSString*)username password:(NSString*)password {
NSMutableURLRequest *request = [self makeRequest:url];
[request setValue:[TSHttpClient stringOfAuthorizationHeaderWithUsername:username password:password]
forHTTPHeaderField:@"Authorization"];
return request;
}
- (void)reset {
[recievedData release];
recievedData = [[NSMutableData alloc] init];
[connection release];
connection = nil;
[rate_limit_reset release];
rate_limit_reset = nil;
statusCode = 0;
contentTypeIsXml = NO;
rate_limit = 0;
rate_limit_remaining = 0;
}
- (void)prepareWithRequest:(NSMutableURLRequest*)request {
// do nothing (for OAuthHttpClient)
}
- (void)requestGET:(NSString*)url {
[self reset];
NSMutableURLRequest *request = [self makeRequest:url];
[self prepareWithRequest:request];
connection = [[NSURLConnection alloc] initWithRequest:request delegate:self startImmediately:YES];
}
- (void)requestPOST:(NSString*)url body:(NSString*)body {
[self reset];
NSMutableURLRequest *request = [self makeRequest:url];
[request setHTTPMethod:@"POST"];
if (body) {
[request setHTTPBody:[body dataUsingEncoding:NSUTF8StringEncoding]];
}
[self prepareWithRequest:request];
connection = [[NSURLConnection alloc] initWithRequest:request delegate:self];
}
- (void)requestGET:(NSString*)url username:(NSString*)username password:(NSString*)password {
[self reset];
NSMutableURLRequest *request = [self makeRequest:url username:username password:password];
connection = [[NSURLConnection alloc] initWithRequest:request delegate:self startImmediately:YES];
}
- (void)requestPOST:(NSString*)url body:(NSString*)body username:(NSString*)username password:(NSString*)password {
[self reset];
NSMutableURLRequest *request = [self makeRequest:url username:username password:password];
[request setHTTPMethod:@"POST"];
if (body) {
[request setHTTPBody:[body dataUsingEncoding:NSUTF8StringEncoding]];
}
connection = [[NSURLConnection alloc] initWithRequest:request delegate:self];
}
- (void)cancel {
[connection cancel];
[self reset];
[self requestFailed:nil];
}
- (void)requestSucceeded {
// implement by subclass
}
- (void)requestFailed:(NSError*)error {
// implement by subclass
}
/*
-(void)connection:(NSURLConnection*)connection didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge*)challenge {
[[challenge sender] cancelAuthenticationChallenge:challenge];
}
*/
- (NSCachedURLResponse *)connection:(NSURLConnection *)connection willCacheResponse:(NSCachedURLResponse *)cachedResponse {
return nil;
}
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
NSLog(@"didReceiveResponse");
statusCode = [(NSHTTPURLResponse*)response statusCode];
NSDictionary *header = [(NSHTTPURLResponse*)response allHeaderFields];
contentTypeIsXml = NO;
NSString *content_type = [header objectForKey:@"Content-Type"];
if (content_type) {
NSRange r = [content_type rangeOfString:@"xml"];
if (r.location != NSNotFound) {
contentTypeIsXml = YES;
}
}
for (NSString *s in [header allKeys]) {
NSLog(@"header: %@", s);
}
NSString *rateLimit = [header objectForKey:@"X-Ratelimit-Limit"];
NSString *rateLimitRemaining = [header objectForKey:@"X-Ratelimit-Remaining"];
NSString *rateLimitReset = [header objectForKey:@"X-Ratelimit-Reset"];
if (rateLimit && rateLimitRemaining) {
rate_limit = [rateLimit intValue];
rate_limit_remaining = [rateLimitRemaining intValue];
rate_limit_reset = [[NSDate dateWithTimeIntervalSince1970:[rateLimitReset intValue]] retain];
NSLog(@"rate_limit: %d rate_limit_remaining:%d",rate_limit, rate_limit_remaining);
}
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
NSLog(@"didReceiveData");
[recievedData appendData:data];
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
NSLog(@"connectionDidFinishLoading");
[self requestSucceeded];
[self reset];
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError*) error {
NSLog(@"didFailWithError");
[self requestFailed:error];
[self reset];
}
@end
#import <Foundation/Foundation.h>
#import "TSHttpClient.h"
@class TSMallClient;
@protocol TSClientDelegate
//请求开始
- (void)tsClientBegin:(TSMallClient*)sender;
//请求结束
- (void)tsClientEnd:(TSMallClient*)sender;
//请求成功
- (void)tsClientSucceeded:(TSMallClient*)sender messages:(NSArray*)messages;
//请求失败
- (void)tsClientFailed:(TSMallClient*)sender;
@end
@interface TSMallClient : TSHttpClient
{
//委托
NSObject<TSClientDelegate> *delegate;
}
@property (readwrite, retain) NSObject<TSClientDelegate> *delegate;
@end
@property (readwrite, retain) NSObject<TSClientDelegate> *delegate;
@end
#import "TSMallClient.h"
@implementation TSMallClient
@synthesize delegate;
- (void)requestSucceeded {
if (statusCode == 200) {
[delegate tsClientSucceeded:self messages:nil];
}
}
-(void) dealloc
{
[delegate release];
[super dealloc];
}
@end
#import <UIKit/UIKit.h>
#import "TSMallClient.h"
@interface TSImg : UIView
{
UIImage *img;
UIImageView *imgviews;
//下载指示器
UIActivityIndicatorView *indicator;
}
@end
#import "TSImg.h"
@implementation TSImg
#define SizeAcitivityIndicator 20.0
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
img=[UIImage imageNamed:@"none.gif"];
UILabel *lb=[[UILabel alloc]init];
[lb setText:@"加载图片"];
[lb setFrame:CGRectMake(50, 10, 100, 50)];
imgviews=[[UIImageView alloc]initWithFrame:[[UIScreen mainScreen]applicationFrame]];
imgviews.image=img;
imgviews.bounds=CGRectMake(0, 150, 320, 320);
indicator = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
//位于imgviews中间
indicator.frame = CGRectMake((imgviews.frame.size.width - SizeAcitivityIndicator) / 2.0, (imgviews.frame.size.height - SizeAcitivityIndicator) / 2.0+150, SizeAcitivityIndicator, SizeAcitivityIndicator);
indicator.hidesWhenStopped = YES;
[imgviews addSubview:indicator];
[indicator startAnimating];
[self addSubview:imgviews];
[self addSubview:lb];
[lb release];
[self downloadImg];
}
return self;
}
//下载图片
-(void) downloadImg
{
TSMallClient *tmc=[[[TSMallClient alloc]init]autorelease];
tmc.delegate=(NSObject<TSClientDelegate>*)self;
[tmc requestGET:@"http://www.yishimai.com/ios/protocol/mountain.jpg"];
}
//下载完成后水平转180度
- (void)tsClientSucceeded:(TSHttpClient*)sender messages:(NSArray*)messages
{
[img release];
img = [[UIImage alloc] initWithData:sender.recievedData];
imgviews.image=img;
[indicator performSelector:@selector(stopAnimating)];
UIViewAnimationTransition trans = UIViewAnimationTransitionFlipFromRight;
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:1.0f];
[UIView setAnimationTransition:trans forView:imgviews cache:YES];
[imgviews exchangeSubviewAtIndex:0 withSubviewAtIndex:1];
[UIView commitAnimations];
}
-(void) dealloc
{
[indicator release];
[imgviews release];
[img release];
[super dealloc];
}
@end
