ios - 如何在 ios7 的 uitableview 单元格中设置背景图像？

Question

我是 ios 的新手，现在有几天我遇到了一个小问题。当加载 TableView 然后上下滚动后背景图像显示 like this这是我的代码

实际上我想将表格显示为聊天设计。我不想使用任何第三方。

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

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


- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {

NSString *comment = [_messages objectAtIndex:indexPath.row];
CGFloat whidt =  250;
UIFont *FONT = [UIFont systemFontOfSize:18];
NSAttributedString *attributedText =[[NSAttributedString alloc]  initWithString:comment  attributes:@  {      NSFontAttributeName: FONT }];
CGRect rect = [attributedText boundingRectWithSize:(CGSize){whidt, MAXFLOAT}
                                           options:NSStringDrawingUsesLineFragmentOrigin
                                           context:nil];
CGSize size = rect.size;
return size.height +50;

}


- (UIFont *)fontForCell{
return [UIFont boldSystemFontOfSize:18.0];
}

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


static NSString *CellIdentifier = @"ChatListItem";

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (!cell) {
    cell = [[UITableViewCell alloc]
            initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];

}

NSString *text = [_messages objectAtIndex:indexPath.row];
CGSize constraint = CGSizeMake(250 , 20000.0f);
UIFont *FONT = [UIFont systemFontOfSize:11];
CGSize size = [text boundingRectWithSize:constraint options:NSStringDrawingUsesLineFragmentOrigin attributes:@{NSFontAttributeName:FONT }context:nil].size;

cell.textLabel.frame = CGRectMake(10, 0, 250, MAX(size.height, 54.0f) + 20.0f);
cell.textLabel.numberOfLines = 0;
cell.textLabel.lineBreakMode = NSLineBreakByWordWrapping;
cell.textLabel.text = text;
cell.textLabel.font = [UIFont systemFontOfSize:18];

UIImage *img = [UIImage imageNamed:@"balloon_selected_right.png"];
CGSize imgSize = cell.textLabel.frame.size;

UIGraphicsBeginImageContext( imgSize );
[img drawInRect:CGRectMake(0,0,250,imgSize.height)];
UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

cell.textLabel.backgroundColor = [UIColor colorWithPatternImage:newImage];

/*[cell.textLabel setText:[_messages objectAtIndex:indexPath.row]];
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
cell.textLabel.text = [_messages objectAtIndex:indexPath.row];*/

return cell;
}

提前致谢!

Answer 1

为此使用自定义委托(delegate)方法。这是您的问题的解决方案...

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    // Configure the cell in each row
    static NSString *CellIdentifier = @"Cell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    cell = [self getCellContentView:CellIdentifier];

    UILabel *textLabel = (UILabel *)[cell viewWithTag:1];
    [textLabel setText:@""];

    textLabel.text = @"some text message to show"; // your text string
    return cell;
}

- (UITableViewCell *)getCellContentView:(NSString *)cellIdentifier
{
    UITableViewCell *cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:cellIdentifier];
    cell.backgroundColor=[UIColor clearColor];

    CGRect labelRect = CGRectMake(20, 5, 100, 30); // set your desired values here
    UIImage *img = [UIImage imageNamed:@"image.png"];
    CGSize imgSize = labelRect.size;

    UIGraphicsBeginImageContext( imgSize );
    [img drawInRect:CGRectMake(0,0,250,imgSize.height)];
    UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    UILabel *textLabel = [[UILabel alloc] initWithFrame:labelRect];
    textLabel.tag=1;
    textLabel.font=[UIFont fontWithName:@"Superclarendon" size:15];
    // some of your other constraints to set ... 
    textLabel.backgroundColor=[UIColor colorWithPatternImage:newImage];
    [cell.contentView addSubview:textLabel];

    return cell;
}