【移動(dòng)應(yīng)用開(kāi)發(fā)技術(shù)】開(kāi)源中國(guó)iOS客戶端學(xué)習(xí)——(八)網(wǎng)絡(luò)通信AFNetworking類庫(kù)

AFNetworking是一個(gè)輕量級(jí)的iOS網(wǎng)絡(luò)通信類庫(kù)，繼ASI類庫(kù)不在更新之后開(kāi)發(fā)者們有一套不錯(cuò)選擇；AFNetworking類庫(kù)×××和使用教程:

/AFNetworking/AFNetworking如果想深入研究有官方文檔介紹:/AFNetworking/在開(kāi)源中國(guó)iOS客戶端中關(guān)于AFNetworking類庫(kù)的使用只用到了兩個(gè)實(shí)例方法(1)getPath:parameters:success:failure:(2)postPath:parameters:success:failure:他們用法基本相同，只是請(qǐng)求數(shù)據(jù)方式不同，一種是Get請(qǐng)求和Post請(qǐng)求。Get是向服務(wù)器發(fā)索取數(shù)據(jù)的一種請(qǐng)求，也就相當(dāng)于查詢信息功能，不會(huì)修改類容，Post是向服務(wù)器提交數(shù)據(jù)的一種請(qǐng)求，影響數(shù)據(jù)內(nèi)容；兩種方法定義：-(void)getPath:(NSString*)pathparameters:(NSDictionary*)parameterssuccess:(void(^)(AFHTTPRequestOperation*operation,idresponseObject))successfailure:(void(^)(AFHTTPRequestOperation*operation,NSError*error))failure{ NSURLRequest*request=[selfrequestWithMethod:@"GET"path:pathparameters:parameters];AFHTTPRequestOperation*operation=[selfHTTPRequestOperationWithRequest:requestsuccess:successfailure:failure];[selfenqueueHTTPRequestOperation:operation];}-(void)postPath:(NSString*)pathparameters:(NSDictionary*)parameterssuccess:(void(^)(AFHTTPRequestOperation*operation,idresponseObject))successfailure:(void(^)(AFHTTPRequestOperation*operation,NSError*error))failure{ NSURLRequest*request=[selfrequestWithMethod:@"POST"path:pathparameters:parameters]; AFHTTPRequestOperation*operation=[selfHTTPRequestOperationWithRequest:requestsuccess:successfailure:failure];[selfenqueueHTTPRequestOperation:operation];}getPath:parameters:success:failure:方法在程序中使用舉例:NewsView.m-(void)reload:(BOOL)noRefresh{//如果有網(wǎng)絡(luò)連接if([ConfigInstance].isNetworkRunning){if(isLoading||isLoadOver){return;}if(!noRefresh){allCount=0;}intpageIndex=allCount/20;NSString*url;switch(self.catalog){case1:url=[NSStringstringWithFormat:@"%@?catalog=%d&pageIndex=%d&pageSize=%d",api_news_list,1,pageIndex,20];break;case2:url=[NSStringstringWithFormat:@"%@?type=latest&pageIndex=%d&pageSize=%d",api_blog_list,pageIndex,20];break;case3:url=[NSStringstringWithFormat:@"%@?type=recommend&pageIndex=%d&pageSize=%d",api_blog_list,pageIndex,20];break;}[[AFOSCClientsharedClient]getPath:urlparameters:Nilsuccess:^(AFHTTPRequestOperation*operation,idresponseObject){[ToolgetOSCNotice2:operation.responseString];isLoading=NO;if(!noRefresh){[selfclear];}@try{NSMutableArray*newNews=self.catalog<=1?[ToolreadStrNewsArray:operation.responseStringandOld:news]:[ToolreadStrUserBlogsArray:operation.responseStringandOld:news];intcount=[ToolisListOver2:operation.responseString];allCount+=count;if(count<20){isLoadOver=YES;}[newsaddObjectsFromArray:newNews];[self.tableNewsreloadData];[selfdoneLoadingTableViewData];//如果是第一頁(yè)則緩存下來(lái)if(news.count<=20){[ToolsaveCache:5andID:self.catalogandString:operation.responseString];}}@catch(NSException*exception){[NdUncaughtExceptionHandlerTakeException:exception];}@finally{[selfdoneLoadingTableViewData];}}failure:^(AFHTTPRequestOperation*operation,NSError*error){NSLog(@"新聞列表獲取出錯(cuò)");//如果是刷新[selfdoneLoadingTableViewData];if([ConfigInstance].isNetworkRunning==NO){return;}isLoading=NO;if([ConfigInstance].isNetworkRunning){[ToolToastNotification:@"錯(cuò)誤網(wǎng)絡(luò)無(wú)連接"andView:self.viewandLoading:NOandIsBottom:NO];}}];isLoading=YES;[self.tableNewsreloadData];}//如果沒(méi)有網(wǎng)絡(luò)連接else{NSString*value=[ToolgetCache:5andID:self.catalog];if(value){NSMutableArray*newNews=[ToolreadStrNewsArray:valueandOld:news];[self.tableNewsreloadData];isLoadOver=YES;[newsaddObjectsFromArray:newNews];[self.tableNewsreloadData];[selfdoneLoadingTableViewData];}}}分析一下這里面的代碼：首先是做一個(gè)網(wǎng)絡(luò)連接判斷，在開(kāi)源中國(guó)iOS客戶端學(xué)習(xí)——(六)網(wǎng)絡(luò)連接檢測(cè)一文中介紹了，作者并不是用這種方法來(lái)判斷，而是使用getPath:parameters:success:failure:來(lái)判斷網(wǎng)絡(luò)的連接，方法使用AFHTTPRequestOperation和“PATCH”請(qǐng)求HTTP客戶端操作隊(duì)列，使用到了block塊(iOS4.0+特性)，URL請(qǐng)求成功執(zhí)行success塊里操作，這里面block塊沒(méi)有返回值，接受兩個(gè)參數(shù)，創(chuàng)建請(qǐng)求操作和響應(yīng)數(shù)據(jù)請(qǐng)求，URL請(qǐng)求失敗執(zhí)行failure里面的方法，這個(gè)block塊里仍沒(méi)有返回值，接受兩個(gè)參數(shù)創(chuàng)建請(qǐng)求操作和NSError對(duì)象，描述網(wǎng)絡(luò)或解析錯(cuò)誤狀況；在

if()中的方法[ConfigInstance].isNetworkRunning==YES的,如果程序加載或者已經(jīng)加載完畢什么也不返回，如果程序沒(méi)有加載數(shù)據(jù)，將數(shù)據(jù)列表數(shù)量顯示為0，接下來(lái)是在switch()中，根據(jù)使用者選擇設(shè)置不同API接口(下圖)，然后就是解析顯示數(shù)據(jù)信息，顯示在視圖中；

在AFNetwork文件夾中，作者自己添加了一個(gè)AFOSCClient類，該類繼承AFHTTPClient，又設(shè)計(jì)了一個(gè)sharedClient的類方法，從返回的結(jié)果可以推測(cè)出它是通過(guò)API請(qǐng)求返回json類型的數(shù)據(jù)，具體什么作用還沒(méi)看出來(lái)；[ToolgetOSCNotice2:operation.responseString];是封裝在在Tool類中的解析獲取的XML的文件URL請(qǐng)求成功，還做了一個(gè)程序異常處理，防止請(qǐng)求數(shù)據(jù)過(guò)成功程序異常崩潰

關(guān)于@try@catch@finally異常處理的使用：如果URL請(qǐng)求的數(shù)據(jù)出錯(cuò)，則反應(yīng)網(wǎng)絡(luò)不連通，數(shù)據(jù)不能加載，則彈出GCDiscreetNotificationView提示視圖

提示網(wǎng)絡(luò)錯(cuò)誤；postPath:parameters:success:failure:方法在程序中使用舉例:FriendsView.m-(void)reload:(BOOL)noRefresh{if(isLoadOver){[selfdoneLoadingTableViewData];return;}[[AFOSCClientsharedClient]postPath:api_friends_listparameters:[NSDictionarydictionaryWithObjectsAndKeys:segement.selectedSegmentIndex==0?@"1":@"0",@"relation",[NSStringstringWithFormat:@"%d",friends.count/20],@"pageIndex",@"20",@"pageSize",[NSStringstringWithFormat:@"%d",[ConfigInstance].getUID],@"uid",nil]success:^(AFHTTPRequestOperation*operation,idresponseObject){if(!noRefresh){[selfclear];}[selfdoneLoadingTableViewData];isLoading=NO;NSString*response=operation.responseString;[ToolgetOSCNotice2:response];@try{TBXML*xml=[[TBXMLalloc]initWithXMLString:responseerror:nil];TBXMLElement*root=xml.rootXMLElement;//顯示TBXMLElement*_friends=[TBXMLchildElementNamed:@"friends"parentElement:root];if(!_friends){isLoadOver=YES;[self.tableFriendsreloadData];return;}TBXMLElement*first=[TBXMLchildElementNamed:@"friend"parentElement:_friends];if(first==nil){[self.tableFriendsreloadData];isLoadOver=YES;return;}NSMutableArray*newFriends=[[NSMutableArrayalloc]initWithCapacity:20];TBXMLElement*name=[TBXMLchildElementNamed:@"name"parentElement:first];TBXMLElement*userid=[TBXMLchildElementNamed:@"userid"parentElement:first];TBXMLElement*portrait=[TBXMLchildElementNamed:@"portrait"parentElement:first];TBXMLElement*expertise=[TBXMLchildElementNamed:@"expertise"parentElement:first];TBXMLElement*gender=[TBXMLchildElementNamed:@"gender"parentElement:first];Friend*f=[[Friendalloc]initWithParameters:[TBXMLtextForElement:name]andUID:[[TBXMLtextForElement:userid]intValue]andPortrait:[TBXMLtextForElement:portrait]andExpertise:[TBXMLtextForElement:expertise]andMale:[[TBXMLtextForElement:gender]intValue]==1];if(![ToolisRepeatFriend:friendsandFriend:f]){[newFriendsaddObject:f];}while(first){first=[TBXMLnextSiblingNamed:@"friend"searchFromElement:first];if(first){name=[TBXMLchildElementNamed:@"name"parentElement:first];userid=[TBXMLchildElementNamed:@"userid"parentElement:first];portrait=[TBXMLchildElementNamed:@"portrait"parentElement:first];expertise=[TBXMLchildElementNamed:@"expertise"parentElement:first];gender=[TBXMLchildElementNamed:@"gender"parentElement:first];f=[[Friendalloc]initWithParameters:[TBXMLtextForElement:name]andUID:[[TBXMLtextForElement:userid]intValue]andPortrait:[TBXMLtextForElement:portrait]andExpertise:[TBXMLtextForElement:expertise]andMale:[[TBXMLtextForElement:gender]intValue]==1];if(![ToolisRepeatFriend:friendsandFriend:f]){[newFriendsaddObject:f];}}elsebreak;