ios - 我有一个 TableView 和五个数据源

Question

我有一个表格 View 。有五个数据源。当我点击数据源切换按钮的时候，但是点击第一个按钮会是空的，其他按钮点击正常，一直没有找到原因。

这是代码:

#import "ViewController.h"

@interface ViewController ()<UITableViewDelegate,UITableViewDataSource>

@property(nonatomic,strong)NSMutableArray * dataArr;
@property(nonatomic,strong)NSMutableArray * dataArr0;
@property(nonatomic,strong)NSMutableArray * dataArr1;
@property(nonatomic,strong)NSMutableArray * dataArr2;
@property(nonatomic,strong)NSMutableArray * dataArr3;
@property(nonatomic,strong)NSMutableArray * dataArr4;

@property(nonatomic,strong)UITableView * mainTab;

@end


static NSString * cellID = @"cellID";

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    NSMutableArray * mutarr0 = [NSMutableArray arrayWithObjects:@"all",@"all",@"all",@"all",@"all", nil];
    self.dataArr0 = mutarr0;

    NSMutableArray * mutarr1 = [NSMutableArray arrayWithObjects:@"Waiting",@"Waiting",@"Waiting",@"Waiting",@"Waiting",@"Waiting", nil];
    self.dataArr1 = mutarr1;

    NSMutableArray * mutarr2 = [NSMutableArray arrayWithObjects:@"processing",@"processing",@"processing",@"processing", nil];
    self.dataArr2 = mutarr2;

    NSMutableArray * mutarr3 = [NSMutableArray arrayWithObjects:@"End",@"End",@"End",@"End",@"End",@"End",@"End", nil];
    self.dataArr3 = mutarr3;

    NSMutableArray * mutarr4 = [NSMutableArray arrayWithObjects:@"cancel",@"cancel",@"cancel",@"cancel",@"cancel", nil];
    self.dataArr4 = mutarr4;

    self.dataArr = mutarr0;

    NSArray * segArr = @[@"all",@"Waiting",@"processing",@"End",@"cancel"];

    UISegmentedControl * segC = [[UISegmentedControl alloc]initWithItems:segArr];

    segC.frame = CGRectMake(0,64, self.view.frame.size.width,50);

    [segC addTarget:self action:@selector(change:) forControlEvents:UIControlEventValueChanged];

    UITableView * tabVC = [[UITableView alloc]initWithFrame:CGRectMake(0, CGRectGetMaxY(segC.frame),self.view.frame.size.width, self.view.frame.size.height - 50) style: UITableViewStylePlain];

    tabVC.delegate = self;
    tabVC.dataSource = self;
    self.mainTab = tabVC;

    [tabVC registerClass:[UITableViewCell class] forCellReuseIdentifier:cellID];

    [self.view addSubview:segC];
    [self.view addSubview:tabVC];
}

-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
    return self.dataArr.count;
}

-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
    UITableViewCell * cell = [tableView dequeueReusableCellWithIdentifier:cellID forIndexPath:indexPath];

    cell.textLabel.text = self.dataArr[indexPath.row];

    return cell;
}

-(void)change:(UISegmentedControl *)sender{
    if (sender.selectedSegmentIndex == 0) {
        [self.dataArr removeAllObjects];
        [self.dataArr addObjectsFromArray:self.dataArr0];

        NSLog(@"%lu33333333333333",self.dataArr.count);
        //        NSLog(@"%lu44444444444444",self.dataArr0.count);
        //        //NSLog(@"%@-------%@",self.dataArr0[0],self.dataArr0[1]);
        [self.mainTab reloadData];
    }else if (sender.selectedSegmentIndex == 1){
        [self.dataArr removeAllObjects];
        [self.dataArr addObjectsFromArray:self.dataArr1];

        NSLog(@"2");
        [self.mainTab reloadData];
    }else if (sender.selectedSegmentIndex == 2){
        //
        [self.dataArr removeAllObjects];
        [self.dataArr addObjectsFromArray:self.dataArr2];

        [self.mainTab reloadData];
        NSLog(@"3");
    }else if (sender.selectedSegmentIndex == 3){
        [self.dataArr removeAllObjects];
        [self.dataArr addObjectsFromArray:self.dataArr3];

        [self.mainTab reloadData];
        //        self.view.backgroundColor = [UIColor blueColor];
        NSLog(@"4");
    }else if (sender.selectedSegmentIndex == 4){
        [self.dataArr removeAllObjects];
        [self.dataArr addObjectsFromArray:self.dataArr4];

        [self.mainTab reloadData];
        //        self.view.backgroundColor = [UIColor orangeColor];
        NSLog(@"5");
    }
}

@end

Answer 1

您的主要问题是在 viewDidLoad 中您执行以下操作:

self.dataArr = mutarr0;

然后在您的 change: 方法中执行以下操作:

[self.dataArr removeAllObjects];

这会删除 mutarr0(也是 self.dataArr0)中的所有值。

解决此问题的最佳方法是更改​​表单的所有行:

[self.dataArr removeAllObjects];
[self.dataArr addObjectsFromArray:self.dataArr4];

到:

self.dataArr = self.dataArr4;

就是这样。无需删除或添加任何对象。

有了这个工作，您还可以做出其他重大改进。主要是摆脱所有数组属性。您不需要 5 个单独的数组属性。只需创建一个代表数组的数组即可。

现在您的代码可以简化为:

@interface ViewController ()<UITableViewDelegate,UITableViewDataSource>

@property(nonatomic,strong) NSMutableArray *current;
@property(nonatomic,strong) NSArray *data;

@property(nonatomic,strong)UITableView * mainTab;

@end


static NSString * cellID = @"cellID";

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    NSMutableArray *mutarr0 = [NSMutableArray arrayWithObjects:@"all",@"all",@"all",@"all",@"all", nil];
    NSMutableArray *mutarr1 = [NSMutableArray arrayWithObjects:@"Waiting",@"Waiting",@"Waiting",@"Waiting",@"Waiting",@"Waiting", nil];
    NSMutableArray *mutarr2 = [NSMutableArray arrayWithObjects:@"processing",@"processing",@"processing",@"processing", nil];
    NSMutableArray *mutarr3 = [NSMutableArray arrayWithObjects:@"End",@"End",@"End",@"End",@"End",@"End",@"End", nil];
    NSMutableArray *mutarr4 = [NSMutableArray arrayWithObjects:@"cancel",@"cancel",@"cancel",@"cancel",@"cancel", nil];

    self.data = @[ mutarr0, mutarr1, mutarr2, mutarr3, mutarr4 ];
    self.current = self.data[0];

    NSArray * egArr = @[ @"all", @"Waiting", @"processing", @"End", @"cancel" ];

    UISegmentedControl * segC = [[UISegmentedControl alloc]initWithItems:segArr];

    segC.frame = CGRectMake(0,64, self.view.frame.size.width,50);

    [segC addTarget:self action:@selector(change:) forControlEvents:UIControlEventValueChanged];

    UITableView * tabVC = [[UITableView alloc]initWithFrame:CGRectMake(0, CGRectGetMaxY(segC.frame),self.view.frame.size.width, self.view.frame.size.height - 50) style: UITableViewStylePlain];

    tabVC.delegate = self;
    tabVC.dataSource = self;
    self.mainTab = tabVC;

    [tabVC registerClass:[UITableViewCell class] forCellReuseIdentifier:cellID];

    [self.view addSubview:segC];
    [self.view addSubview:tabVC];
}

-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
    return self.current.count;
}

-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
    UITableViewCell * cell = [tableView dequeueReusableCellWithIdentifier:cellID forIndexPath:indexPath];

    cell.textLabel.text = self.current[indexPath.row];

    return cell;
}

-(void)change:(UISegmentedControl *)sender{
    if (sender.selectedSegmentIndex != UISegmentedControlNoSegment {
        self.current = self.data[sender.selectedSegmentIndex];
        [self.mainTab reloadData];
    }
}

@end