实现 UISegmentControl 与 UIScrollView的上下级联（分别在相应的方法中加入级联代码）

实现 UISegmentControl 与 UIScrollView的上下级联，需要在

[segmentCtr addTarget:self action:@selector(segmentedControlValueChanged:) forControlEvents:UIControlEventValueChanged];方法中加入// （级联）根据选中的第几段来计算scrollView的滚动位置（contentOffSet）

和

-(void)scrollViewDidScroll:(UIScrollView *)scrollView;方法中分别加入"@@级联@@"的代码计算// （级联）根据scrollView的滚动位置决定显示第几段

//

//  ViewController.m

//  ScrollPlayerDemo

//

//  Created by diesel on 16/2/21.

//  Copyright © 2016年 JingFang. All rights reserved.

//

#import "ViewController.h"

#define ScreenWidth self.view.frame.size.width

#define ScreenHeight self.view.frame.size.height

@interface ViewController ()<UITableViewDataSource,UITableViewDelegate>

{

UIScrollView *myScrollView;

UITableView *tableView0;

NSArray *dataSource0;

//    UITableView *tableView1;

NSArray *dataSource1;

//

//    UITableView *tableView2;

NSArray *dataSource2;

UISegmentedControl *segmentCtr;

}

@end

@implementation ViewController

- (void)viewDidLoad {

[super viewDidLoad];

[self createUI];

}

- (void)createUI{

segmentCtr = [[UISegmentedControl alloc]initWithItems:@[@"昨天",@"今天",@"明天"]];

segmentCtr.frame = CGRectMake(100, 20, 200, 40);

segmentCtr.selectedSegmentIndex = 0;

[segmentCtr addTarget:self action:@selector(segmentedControlValueChanged:) forControlEvents:UIControlEventValueChanged];

[self.view addSubview:segmentCtr];

dataSource0 = @[@"1",@"2",@"3",@"4",@"1",@"2",@"3",@"4",@"1",@"2",@"3",@"4"];

dataSource1 = @[@"11",@"22",@"33",@"44"];

dataSource2 = @[@"1111",@"211",@"311",@"4",@"1",@"2",@"3",@"4"];

myScrollView = [[UIScrollView alloc]initWithFrame:CGRectMake(0, 80, ScreenWidth , ScreenHeight)];

myScrollView.backgroundColor = [UIColor yellowColor];

myScrollView.pagingEnabled = YES;

myScrollView.delegate = self;

myScrollView.showsHorizontalScrollIndicator = NO;

myScrollView.contentSize = CGSizeMake(ScreenWidth * 3, ScreenHeight);

[self.view addSubview:myScrollView];

for (int i = 0; i<3; i++) {

tableView0 = [[UITableView alloc]init];

tableView0.frame = CGRectMake(0+ScreenWidth*i, 0, ScreenWidth, ScreenHeight-160);

tableView0.tag = i+1;

tableView0.dataSource = self;

tableView0.delegate = self;

[myScrollView addSubview:tableView0];

}

}

-(void)segmentedControlValueChanged:(UISegmentedControl *)segment{

//级联

CGFloat offsetX = segment.selectedSegmentIndex * ScreenWidth;

CGPoint offset = CGPointMake(offsetX, 0);

[myScrollView setContentOffset:offset animated:YES];

//    UITableView *tableView = [myScrollView viewWithTag:segmentCtr.selectedSegmentIndex + 1];

//    [tableView reloadData];

}

-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{

if (segmentCtr.selectedSegmentIndex == 0) {

return dataSource0.count;

}else if(segmentCtr.selectedSegmentIndex == 1){

return dataSource1.count;

}

return dataSource2.count;

}

-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{

static NSString *string = @"string";

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:string];

if (!cell) {

cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:string];

}

if (segmentCtr.selectedSegmentIndex == 0) {

cell.textLabel.text = dataSource0[indexPath.row];

}else if(segmentCtr.selectedSegmentIndex == 1){

cell.textLabel.text = dataSource1[indexPath.row];

}else{

cell.textLabel.text = dataSource2[indexPath.row];

}

return cell;

}

-(void)scrollViewDidScroll:(UIScrollView *)scrollView{

// （级联）根据scrollView的滚动位置决定显示 第几段

CGFloat scrollW = scrollView.frame.size.width;

int page = (scrollView.contentOffset.x + scrollW * 0.5) / scrollW;

segmentCtr.selectedSegmentIndex = page;

//当换页时，重新加载数据源（注意：tag值不能从0开始）

UITableView *tableView = [self.view viewWithTag:segmentCtr.selectedSegmentIndex + 1];

[tableView reloadData];

}

- (void)didReceiveMemoryWarning {

[super didReceiveMemoryWarning];

// Dispose of any resources that can be recreated.

}

@end