1 //
 2 //  MainViewController.m
 3 //  TableViewSreenShot
 4 //
 5 //  Created by ChenJungang on 14/11/8.
 6 //  Copyright (c) 2014年 ChenJungang. All rights reserved.
 7 //
 8
 9 #import "MainViewController.h"
10 #import "MainCell.h"
11
12 #define kTableViewRowCount 30
13 #define kTableViewHeight 76
14
15 @interface MainViewController ()
16 @property (strong, nonatomic) IBOutlet UITableView *tableView;
17 @end
18
19 @implementation MainViewController
20
21 - (void)viewDidLoad {
22     [super viewDidLoad];
23     // Do any additional setup after loading the view from its nib.
24     self.title = @"screen shot";
25     self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"share" style:UIBarButtonItemStylePlain target:self action:@selector(screenshotAction:)];
26 }
27
28 - (void)screenshotAction:(id)sender{
29
30     NSMutableArray *indexPaths = [NSMutableArray array];
31     for(NSUInteger i = 0; i < [self.tableView numberOfRowsInSection:0]; i++){
32         [indexPaths addObject:[NSIndexPath indexPathForRow:i inSection:0]];
33     }
34     UIImage *image = [self screenShotForIndexPaths:indexPaths];
35     UIActivityViewController *activityVC = [[UIActivityViewController alloc] initWithActivityItems:@[image] applicationActivities:nil];
36     [self.navigationController presentViewController:activityVC animated:YES completion:NULL];
37 }
38
39 #pragma mark - UITableViewDataSource
40 - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
41     return kTableViewRowCount;
42 }
43
44 - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView{
45     return 1;
46 }
47
48 - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
49     static NSString *mainCellId = @"CellId";
50     MainCell *mainCell = [tableView dequeueReusableCellWithIdentifier:mainCellId];
51     if (!mainCell) {
52         mainCell = [MainCell loadFromXib];
53     }
54     mainCell.accountNameLabel.text = [NSString stringWithFormat:@"row : %ld",(long)indexPath.row];
55     return mainCell;
56 }
57
58 #pragma mark - UITableViewDelegate
59 - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
60     [tableView deselectRowAtIndexPath:indexPath animated:YES];
61 }
62 - (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath{
63     return kTableViewHeight;
64 }
65
66 #pragma mark - Screen shot Method
67 - (UIImage*)screenShotForIndexPaths:(NSArray*)indexPaths
68 {
69     CGPoint originalOffset = self.tableView.contentOffset;
70
71     UIGraphicsBeginImageContextWithOptions(CGSizeMake(CGRectGetWidth(self.tableView.frame), self.tableView.rowHeight * indexPaths.count), NO, 0.0);
72     CGContextRef ctx = UIGraphicsGetCurrentContext();
73
74     //将cell逐个渲染到CGContext上
75     MainCell *cell = nil;
76     for (NSIndexPath *indexPath in indexPaths) {
77
78         //找到相应位置的cell，渲染出來
79         [self.tableView scrollToRowAtIndexPath:indexPath atScrollPosition:UITableViewScrollPositionNone animated:NO];
80         cell = (MainCell *)[self.tableView cellForRowAtIndexPath:indexPath];
81         [cell.layer renderInContext:ctx];
82
83         //在context上渲染的origin
84         CGContextTranslateCTM(ctx, 0, self.tableView.rowHeight);
85     }
86
87     UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
88     UIGraphicsEndImageContext();
89     self.tableView.contentOffset = originalOffset;
90     return image;
91 }
92
93
94 - (void)didReceiveMemoryWarning {
95     [super didReceiveMemoryWarning];
96     // Dispose of any resources that can be recreated.
97 }
98
99 @end