为什么这段代码什么都不做

Question

我正在制作一个新的实时聊天应用程序，我创建了一个包含聊天室的UIViewController，当有人点击一个单元格时，它打开了我创建的UIViewController，我编写了一个代码，但它没有做任何事情只是打开UIViewController没有任何反应！

这是chatTableView的代码

@implementation DMChatViewController


//---add this---
@synthesize chatTableView;

NSMutableArray *listOfMessages;
NSMutableArray *dateOfMessages;

static CGFloat const FONTSIZE = 14.0;
static int const DATELABEL_TAG = 1;
static int const MESSAGELABEL_TAG = 2;
static int const IMAGEVIEW_TAG_1 = 3;
static int const IMAGEVIEW_TAG_2 = 4;
static int const IMAGEVIEW_TAG_3 = 5;
static int const IMAGEVIEW_TAG_4 = 6;
static int const IMAGEVIEW_TAG_5 = 7;
static int const IMAGEVIEW_TAG_6 = 8;
static int const IMAGEVIEW_TAG_7 = 9;
static int const IMAGEVIEW_TAG_8 = 10;
static int const IMAGEVIEW_TAG_9 = 11;

int bubbleFragment_width, bubbleFragment_height;
int bubble_x, bubble_y;
//--------------

- (id)initWithStyle:(UITableViewStyle)style
{
    self = [super initWithStyle:style];

    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)viewDidLoad
{

    bubble_x = 10;
    bubble_y = 20;

    //---size of the bubble fragment---
    bubbleFragment_width = 56;
    bubbleFragment_height = 32;

    //---contains the messages---
    listOfMessages = [[NSMutableArray alloc] init];

    //---contains the date for each message---
    dateOfMessages = [[NSMutableArray alloc] init];

    //---add a message---
    [listOfMessages addObject:@"Hello!"];
    [dateOfMessages addObject:[NSString stringWithFormat:@"%@",[NSDate date]]];
    //--------------


    [super viewDidLoad];
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (NSInteger)numberOfSectionsInTableView:(UITableView *)chatTableView
{
    return 1;
}

- (NSInteger)chatTableView:(UITableView *)chatTableView numberOfRowsInSection:    (NSInteger)section
{
    return [listOfMessages count];
}

//---calculate the height for the message---
-(CGFloat) labelHeight:(NSString *) text
{
    CGSize maximumLabelSize = CGSizeMake((bubbleFragment_width * 3) - 25,9999);

    CGSize expectedLabelSize = [text sizeWithFont:[UIFont systemFontOfSize: FONTSIZE] constrainedToSize:maximumLabelSize lineBreakMode:NSLineBreakByWordWrapping];
    /** CGSize expectedLabelSize = [text sizeWithFont:[UIFont systemFontOfSize: FONTSIZE] constrainedToSize:maximumLabelSize lineBreakMode:UILineBreakModeWordWrap]; **/

    // CGSize expectedLabelSize = [text sizeWithAttributes: @{NSFontAttributeName: [UIFont systemFontOfSize: FONTSIZE]} /** constrainedToSize:maximumLabelSize lineBreakMode:NSLineBreakByWordWrapping **/];
    return expectedLabelSize.height;
}

//---returns the height for the table view row---
- (CGFloat)chatTableView:(UITableView *)chatTableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
    int labelHeight = [self labelHeight:[listOfMessages objectAtIndex:indexPath.row]];
    labelHeight -= bubbleFragment_height;
    if (labelHeight<0) labelHeight = 0;

    return (bubble_y + bubbleFragment_height * 2 + labelHeight) + 5;
}

- (UITableViewCell *)chatTableView:(UITableView *)chatTableCell cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"Cell";

    //---add this---
    UILabel* dateLabel = nil;
    UILabel* messageLabel = nil;
    UIImageView *imageView_top_left = nil;
    UIImageView *imageView_top_middle = nil;
    UIImageView *imageView_top_right = nil;

    UIImageView *imageView_middle_left = nil;
    UIImageView *imageView_middle_right = nil;
    UIImageView *imageView_middle_middle = nil;

    UIImageView *imageView_bottom_left = nil;
    UIImageView *imageView_bottom_middle = nil;
    UIImageView *imageView_bottom_right = nil;
    //--------------

    UITableViewCell *cell = [chatTableCell dequeueReusableCellWithIdentifier:CellIdentifier];

    if (cell == nil) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];

        //---add this---
        //---date---
        dateLabel = [[UILabel alloc] init];
        dateLabel.tag = DATELABEL_TAG;
        [cell.contentView addSubview: dateLabel];

        //---top left---
        imageView_top_left = [[UIImageView alloc] init];
        imageView_top_left.tag = IMAGEVIEW_TAG_1;
        [cell.contentView addSubview: imageView_top_left];

        //---top middle---
        imageView_top_middle = [[UIImageView alloc] init];
        imageView_top_middle.tag = IMAGEVIEW_TAG_2;
        [cell.contentView addSubview: imageView_top_middle];

        //---top right---
        imageView_top_right = [[UIImageView alloc] init];
        imageView_top_right.tag = IMAGEVIEW_TAG_3;
        [cell.contentView addSubview: imageView_top_right];

        //---middle left---
        imageView_middle_left = [[UIImageView alloc] init];
        imageView_middle_left.tag = IMAGEVIEW_TAG_4;
        [cell.contentView addSubview: imageView_middle_left];

        //---middle middle---
        imageView_middle_middle = [[UIImageView alloc] init];
        imageView_middle_middle.tag = IMAGEVIEW_TAG_5;
        [cell.contentView addSubview: imageView_middle_middle];

        //---middle right---
        imageView_middle_right = [[UIImageView alloc] init];
        imageView_middle_right.tag = IMAGEVIEW_TAG_6;
        [cell.contentView addSubview: imageView_middle_right];

        //---bottom left---
        imageView_bottom_left = [[UIImageView alloc] init];
        imageView_bottom_left.tag = IMAGEVIEW_TAG_7;
        [cell.contentView addSubview: imageView_bottom_left];

        //---bottom middle---
        imageView_bottom_middle = [[UIImageView alloc] init];
        imageView_bottom_middle.tag = IMAGEVIEW_TAG_8;
        [cell.contentView addSubview: imageView_bottom_middle];

        //---bottom right---
        imageView_bottom_right = [[UIImageView alloc] init];
        imageView_bottom_right.tag = IMAGEVIEW_TAG_9;
        [cell.contentView addSubview: imageView_bottom_right];

        //---message---
        messageLabel = [[UILabel alloc] init];
        messageLabel.tag = MESSAGELABEL_TAG;
        [cell.contentView addSubview: messageLabel];

        //---set the images to display for each UIImageView---
        imageView_top_left.image =
            [UIImage imageNamed:@"bubble_top_left.png"];
        imageView_top_middle.image =
            [UIImage imageNamed:@"bubble_top_middle.png"];
        imageView_top_right.image =
            [UIImage imageNamed:@"bubble_top_right.png"];

        imageView_middle_left.image =
            [UIImage imageNamed:@"bubble_middle_left.png"];
        imageView_middle_middle.image =
            [UIImage imageNamed:@"bubble_middle_middle.png"];
        imageView_middle_right.image =
            [UIImage imageNamed:@"bubble_middle_right.png"];

        imageView_bottom_left.image =
            [UIImage imageNamed:@"bubble_bottom_left.png"];
        imageView_bottom_middle.image =
            [UIImage imageNamed:@"bubble_bottom_middle.png"];
        imageView_bottom_right.image =
            [UIImage imageNamed:@"bubble_bottom_right.png"];

    } else {
        //---reuse the old views---
        dateLabel = (UILabel*)[cell.contentView viewWithTag: DATELABEL_TAG];
        messageLabel = (UILabel*)[cell.contentView viewWithTag: MESSAGELABEL_TAG];

        imageView_top_left =
            (UIImageView*)[cell.contentView viewWithTag: IMAGEVIEW_TAG_1];
        imageView_top_middle =
            (UIImageView*)[cell.contentView viewWithTag: IMAGEVIEW_TAG_2];
        imageView_top_right =
            (UIImageView*)[cell.contentView viewWithTag: IMAGEVIEW_TAG_3];

        imageView_middle_left =
            (UIImageView*)[cell.contentView viewWithTag: IMAGEVIEW_TAG_4];
        imageView_middle_middle =
            (UIImageView*)[cell.contentView viewWithTag: IMAGEVIEW_TAG_5];
        imageView_middle_right =
            (UIImageView*)[cell.contentView viewWithTag: IMAGEVIEW_TAG_6];

        imageView_bottom_left =
            (UIImageView*)[cell.contentView viewWithTag: IMAGEVIEW_TAG_7];
        imageView_bottom_middle =
            (UIImageView*)[cell.contentView viewWithTag: IMAGEVIEW_TAG_8];
        imageView_bottom_right =
            (UIImageView*)[cell.contentView viewWithTag: IMAGEVIEW_TAG_9];
    }

    //---calculate the height for the label---
    int labelHeight = [self labelHeight:[listOfMessages objectAtIndex:indexPath.row]];
    labelHeight -= bubbleFragment_height;
    if (labelHeight<0) labelHeight = 0;

    //---you can customize the look and feel for the date for each message here---
    dateLabel.frame = CGRectMake(0.0, 0.0, 200, 15.0);
    dateLabel.font = [UIFont boldSystemFontOfSize: FONTSIZE];
    dateLabel.textAlignment = NSTextAlignmentCenter; // edited
    dateLabel.textColor = [UIColor darkGrayColor];
    dateLabel.backgroundColor = [UIColor clearColor];

    /**

    dateLabel.frame = CGRectMake(0.0, 0.0, 200, 15.0);
    dateLabel.font = [UIFont boldSystemFontOfSize: FONTSIZE];
    dateLabel.textAlignment = UITextAlignmentLeft;
    dateLabel.textColor = [UIColor darkGrayColor];
    dateLabel.backgroundColor = [UIColor clearColor]; **/

    //---top left---
    imageView_top_left.frame =
    CGRectMake(bubble_x, bubble_y, bubbleFragment_width, bubbleFragment_height);
    //---top middle---
    imageView_top_middle.frame =
    CGRectMake(bubble_x + bubbleFragment_width, bubble_y,
               bubbleFragment_width, bubbleFragment_height);
    //---top right---
    imageView_top_right.frame =
    CGRectMake(bubble_x + (bubbleFragment_width * 2), bubble_y,
               bubbleFragment_width, bubbleFragment_height);
    //---middle left---
    imageView_middle_left.frame =
    CGRectMake(bubble_x, bubble_y + bubbleFragment_height,
               bubbleFragment_width, labelHeight);
    //---middle middle---
    imageView_middle_middle.frame =
    CGRectMake(bubble_x + bubbleFragment_width, bubble_y + bubbleFragment_height,
               bubbleFragment_width, labelHeight);
    //---middle right---
    imageView_middle_right.frame =
    CGRectMake(bubble_x + (bubbleFragment_width * 2),
               bubble_y + bubbleFragment_height,
               bubbleFragment_width, labelHeight);
    //---bottom left---
    imageView_bottom_left.frame =
    CGRectMake(bubble_x, bubble_y + bubbleFragment_height + labelHeight,
               bubbleFragment_width, bubbleFragment_height );
    //---bottom middle---
    imageView_bottom_middle.frame =
    CGRectMake(bubble_x + bubbleFragment_width,
               bubble_y + bubbleFragment_height + labelHeight,
               bubbleFragment_width, bubbleFragment_height);
    //---bottom right---
    imageView_bottom_right.frame =
    CGRectMake(bubble_x + (bubbleFragment_width * 2),
               bubble_y + bubbleFragment_height + labelHeight,
               bubbleFragment_width, bubbleFragment_height );

    //---you can customize the look and feel for each message here---
    messageLabel.frame =
    CGRectMake(bubble_x + 10, bubble_y + 5,
               (bubbleFragment_width * 3) - 25,
               (bubbleFragment_height * 2) + labelHeight - 10);

    messageLabel.font = [UIFont systemFontOfSize:FONTSIZE];
    messageLabel.textAlignment = NSTextAlignmentCenter;
    messageLabel.textColor = [UIColor darkTextColor];
    messageLabel.numberOfLines = 0; //---display multiple lines---
    messageLabel.backgroundColor = [UIColor clearColor];
    messageLabel.lineBreakMode = NSLineBreakByWordWrapping;

    dateLabel.text = [dateOfMessages objectAtIndex:indexPath.row];
    messageLabel.text = [listOfMessages objectAtIndex:indexPath.row];
    //--------------

    return cell;
}

/**
//---add a message to the table view---
- (IBAction)btnAdd:(id) sender
{
[listOfMessages addObject:itemName.text];
[dateOfMessages addObject:[NSString stringWithFormat:@"%@",[NSDate date]]];

[self.tableView reloadData];
}
**/


@end

Answer 1

如果您正在尝试提供数据源＆amp;委托UITableView的方法，你已经错误地命名了你的方法。例如，

- (NSInteger)chatTableView:numberOfRowsInSection: 

应该是

- (NSInteger)tableView:numberOfRowsInSection: 

Answer 2

您是否期望UITableViewDelegate调用

chatTableView:(UITableView *)chatTableCell cellForRowAtIndexPath:(NSIndexPath *)indexPath

方法给你？

如果你是，你不知道代表是如何工作的。将该方法更改为：

tableView:(UITableView *)chatTableCell cellForRowAtIndexPath:(NSIndexPath *)indexPath