Question

我有以下代码从URL获取数据，将其存储在数组中，并在表格中显示。

现在的问题是我的网址，根据按钮点击向表格提供数据更改，即如果用户点击按钮[获取者]，则会从与获取者相关的网址中提取数据，等等。

正如我在didLoad方法中调用了gainer方法，最初的数据是从相应的URL显示的。但是在按钮上单击不执行任何操作。原因是我在方法（gainer和looser）中填充数组，但是表在创建表时从数组中获取数据（此时数组为空）。

我在设计视图中创建了按钮，而我正在以编程方式创建表格。

fetchdataViewController.h

#import <UIKit/UIKit.h>

@interface fetchdataViewController : UIViewController<UITableViewDataSource,UITableViewDelegate>{
    IBOutlet UIWebView *webView;
    NSMutableArray *arr1;
    NSMutableArray *atarr;
    NSMutableArray *arr2;
    NSMutableArray *a;
    NSMutableArray *b;
    NSMutableArray *c;
    NSMutableArray *d;
    UITableView *aTableView;
}
-(IBAction)btnClicked:(id)sender;
-(IBAction)btnClicked1:(id)sender;
-(void)gainer;
-(void)looser;
@property(nonatomic,retain)NSMutableArray *arr1;
@property(nonatomic,retain)NSMutableArray *arr2;
@property(nonatomic,retain)NSMutableArray *atarr;
@property(nonatomic,retain)NSMutableArray *a;
@property(nonatomic,retain)NSMutableArray *b;
@property(nonatomic,retain)NSMutableArray *c;
@property(nonatomic,retain)NSMutableArray *d;
@property(nonatomic,retain)UIWebView *webView;
@property(nonatomic,retain)UITableView *aTableView;
@end

fetchdataViewController.m

#import "fetchdataViewController.h"

@implementation fetchdataViewController

NSMutableArray *atarr;
NSMutableArray *arr1;
NSMutableArray *arr2;
NSMutableArray *a;
NSMutableArray *b;
NSMutableArray *c;
NSMutableArray *d;
NSMutableString *mainstr;
NSMutableString *str;
@synthesize webView;
@synthesize arr1;
@synthesize arr2;
@synthesize atarr;
@synthesize a;
@synthesize b;
@synthesize c;
@synthesize d;
@synthesize aTableView;

int i,j;

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return [a count];
}
- (UITableViewCell *)tableView:(UITableView *)tableView 
         cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    static NSString *CellIdentifier=@"Cell"; 

    static NSInteger StateTag = 1;
    static NSInteger CapitalTag = 2;
    static NSInteger StateTag1 = 3;
    static NSInteger StateTag2 = 4;


    UITableViewCell *cell=[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if(cell == nil){
        cell=[[[UITableViewCell alloc]initWithFrame:CGRectZero reuseIdentifier:CellIdentifier]autorelease];
        CGRect frame;
        frame.origin.x = 10; 
        frame.origin.y = 5;
        frame.size.height = 35;
        frame.size.width = 170;


        UILabel *capitalLabel = [[UILabel alloc] initWithFrame:frame];
        capitalLabel.tag = CapitalTag;
        [cell.contentView addSubview:capitalLabel];     

        frame.origin.x += 125;
        UILabel *stateLabel = [[UILabel alloc] initWithFrame:frame];
        stateLabel.tag = StateTag;
        [cell.contentView addSubview:stateLabel];

        frame.origin.x += 100;
        UILabel *stateLabel1 = [[UILabel alloc] initWithFrame:frame];
        stateLabel1.tag = StateTag1;
        [cell.contentView addSubview:stateLabel1];


        frame.origin.x += 100;
        UILabel *stateLabel2 = [[UILabel alloc] initWithFrame:frame];
        stateLabel2.tag = StateTag2;
        [cell.contentView addSubview:stateLabel2];


    }
    UILabel *capitalLabel = (UILabel *) [cell.contentView viewWithTag:CapitalTag];
    UILabel *stateLabel = (UILabel *) [cell.contentView viewWithTag:StateTag];
    UILabel *stateLabel1 = (UILabel *) [cell.contentView viewWithTag:StateTag1];
    UILabel *stateLabel2 = (UILabel *) [cell.contentView viewWithTag:StateTag2];

    capitalLabel.text=[a objectAtIndex:indexPath.row];
    stateLabel.text = [b objectAtIndex:indexPath.row];
    stateLabel1.text = [c objectAtIndex:indexPath.row];
    stateLabel2.text = [d objectAtIndex:indexPath.row];


    return cell;
}


-(IBAction)btnClicked:(id)sender{
    [self gainer];
}

-(IBAction)btnClicked1:(id)sender {

    [self looser];
}

-(void)gainer{
    arr1=[[NSMutableArray alloc]init];
    arr2=[[NSMutableArray alloc]init];
    a=[[NSMutableArray alloc]init];
    b=[[NSMutableArray alloc]init];
    c=[[NSMutableArray alloc]init];
    d=[[NSMutableArray alloc]init];

    NSURL *url=[NSURL URLWithString:@"http://ipad.idealake.com/default.aspx?id=G"];
    NSURLRequest *req=[NSURLRequest requestWithURL:url];
    [webView loadRequest:req];

    //storing page data in string
    mainstr=[[NSMutableString alloc] initWithContentsOfURL:url];
    atarr=[mainstr componentsSeparatedByString:@"@"];

    NSString *str2;
    NSString *str3;
    for(int i=0; i<[atarr count]-1; i++)
    {
        // NSLog(@"i=:%i",i); 

        NSMutableString *str = [atarr objectAtIndex:i];
        if (str!= nil)            
            arr1=[str componentsSeparatedByString:@";"];
            for (int k=0;k<[arr1 count];k++)
            {                
                str2 = [arr1 objectAtIndex:k];                
                [arr2 addObject:str2];
                            }


        }
        else
        {
            //NSLog (@"Nill");
        }

    }
    for(int l=0;l<[arr2 count]/4;l++){
        str3=[arr2 objectAtIndex:4*l];
        [a addObject:str3];

        str3=[arr2 objectAtIndex:(4*l)+1];
        [b addObject:str3];

        str3=[arr2 objectAtIndex:(4*l)+2];
        [c addObject:str3];

        str3=[arr2 objectAtIndex:(4*l)+3];
        [d addObject:str3];
    }    
}

-(void)looser{

    arr1=[[NSMutableArray alloc]init];
    arr2=[[NSMutableArray alloc]init];
    a=[[NSMutableArray alloc]init];
    b=[[NSMutableArray alloc]init];
    c=[[NSMutableArray alloc]init];
    d=[[NSMutableArray alloc]init];

    NSURL *url=[NSURL URLWithString:@"http://ipad.idealake.com/default.aspx?id=L"];
    NSURLRequest *req=[NSURLRequest requestWithURL:url];
    [webView loadRequest:req];

    mainstr=[[NSMutableString alloc] initWithContentsOfURL:url];
    atarr=[mainstr componentsSeparatedByString:@"@"];

    NSString *str2;
    NSString *str3;
    for(int i=0; i<[atarr count]-1; i++)
    {

        NSMutableString *str = [atarr objectAtIndex:i];
        if (str!= nil)
        {

            arr1=[str componentsSeparatedByString:@";"];
            for (int k=0;k<[arr1 count];k++)
            {

                str2 = [arr1 objectAtIndex:k];
                [arr2 addObject:str2];
            }          

        }
        else
        {
            //NSLog (@"Nill");
        }

    }
    for(int l=0;l<[arr2 count]/4;l++){
        str3=[arr2 objectAtIndex:4*l];
        [a addObject:str3];

        str3=[arr2 objectAtIndex:(4*l)+1];
        [b addObject:str3];

        str3=[arr2 objectAtIndex:(4*l)+2];
        [c addObject:str3];

        str3=[arr2 objectAtIndex:(4*l)+3];
        [d addObject:str3];
    }
}


- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
}

#pragma mark - View lifecycle

- (void)viewDidLoad
{
    arr1=[[NSMutableArray alloc]init];
    arr2=[[NSMutableArray alloc]init];
    a=[[NSMutableArray alloc]init];
    b=[[NSMutableArray alloc]init];
    c=[[NSMutableArray alloc]init];
    d=[[NSMutableArray alloc]init];

    [self gainer];
    [super viewDidLoad];

    aTableView = [[UITableView alloc] initWithFrame:[[UIScreen mainScreen]applicationFrame] style:UITableViewStyleGrouped];
    aTableView.dataSource = self;
    aTableView.delegate = self;
    aTableView.frame = CGRectMake(0, 10, 720, 500);
    [self.view addSubview:aTableView];

    [super viewDidLoad];
}

- (void)viewDidUnload
{
    [super viewDidUnload];
}

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
}

- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];
}

- (void)viewWillDisappear:(BOOL)animated
{
    [super viewWillDisappear:animated];
}

- (void)viewDidDisappear:(BOOL)animated
{
    [super viewDidDisappear:animated];
}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    // Return YES for supported orientations
    return YES;
}

@end

更新

当我运行以下代码时，我得到了这个输出。灰色阴影部分是我主要担心的问题。

Screenshot 感谢提前

Answer 1

您需要通过致电UITableView告诉您的reloadData数据已更改。

Answer 2

每次更改网址后使用[self.tableview reloadData]并填充新数组。

动态填充UITableView

2 个答案: