Iphone 当UIImage不存在时如何显示UILabel
我有一个从服务器加载图像的UITableView。但有时UITableView上没有要显示的图像,因此我希望显示UILabel。想知道我该如何做到这一点。我将感谢任何帮助或代码片段来实现这一点。 多谢各位 我试过你说的了。第一次加载表格时,一切正常,但一旦开始滚动所有标签和按钮,所有位置都会显示出来。Iphone 当UIImage不存在时如何显示UILabel,iphone,ios,uitableview,uilabel,Iphone,Ios,Uitableview,Uilabel,我有一个从服务器加载图像的UITableView。但有时UITableView上没有要显示的图像,因此我希望显示UILabel。想知道我该如何做到这一点。我将感谢任何帮助或代码片段来实现这一点。 多谢各位 我试过你说的了。第一次加载表格时,一切正常,但一旦开始滚动所有标签和按钮,所有位置都会显示出来。 这是我的密码 - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowA
这是我的密码
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = @"Cell";
UITableViewCell *cell = [self.tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
cell.selectionStyle = UITableViewCellSelectionStyleNone;
}
if (msgImgFile){
NSLog (@"Image file found!");
lblOne = [[UILabel alloc] initWithFrame:CGRectMake(10, 360, 200, 20)];
lblTwo = [[UILabel alloc] initWithFrame:CGRectMake(10, 378, 150, 20)];
lblThree = [[UILabel alloc] initWithFrame:CGRectMake(10, 398, 150, 20)];
btnPlayStop.frame = CGRectMake(255.0f, 375.0f, 30.0f, 30.0f);
}
else
{
NSLog(@"Image file not found. Simply load the UILabel and UIButton");
lblOne = [[UILabel alloc] initWithFrame:CGRectMake(10, 50, 200, 20)];
lblTwo = [[UILabel alloc] initWithFrame:CGRectMake(10, 68, 150, 20)];
lblThree = [[UILabel alloc] initWithFrame:CGRectMake(10, 88, 150, 20)];
btnPlayStop.frame = CGRectMake(255.0f, 45.0f, 30.0f, 30.0f);
}
lblOne.font = [UIFont fontWithName:@"Arial" size:12];
[lblOne setBackgroundColor:[UIColor clearColor]];
lblOne.tag = 1;
lblTwo.font = [UIFont fontWithName:@"Arial" size:12];
[lblTwo setBackgroundColor:[UIColor clearColor]];
lblTwo.tag = 2;
lblThree.font = [UIFont fontWithName:@"Arial" size:10];
[lblThree setBackgroundColor:[UIColor clearColor]];
lblThree.tag = 3;
lblFour = [[UILabel alloc] initWithFrame:CGRectMake(10, 24, 150, 20)];
lblFour.font = [UIFont fontWithName:@"Arial" size:12];
[lblFour setBackgroundColor:[UIColor clearColor]];
lblFour.tag = 4;
btnPlayStop = [UIButton buttonWithType:UIButtonTypeCustom];
[btnPlayStop setTitle:@"Play" forState:UIControlStateNormal];
[btnPlayStop setImage:[UIImage imageNamed:@"Play Button.png"] forState:UIControlStateNormal];
[btnPlayStop addTarget:self action:@selector(playRecordClicked:) forControlEvents:UIControlEventTouchUpInside];
[cell addSubview:lblOne];
[cell addSubview:lblTwo];
[cell addSubview:lblThree];
[cell addSubview:lblFour];
[cell.contentView addSubview:btnPlayStop];
dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0);
dispatch_async(queue, ^{
msgObjImg = (PFObject *)[self.imageDataMutArray objectAtIndex:indexPath.row];
createdDt = msgObjImg.createdAt;
msgImgFile = [msgObjImg objectForKey:@"siqImage"];
NSData *imgData = [msgImgFile getData];
UIImage *msgImgFound = [UIImage imageWithData:imgData];
UIImage *newImg = [self scaleImage:msgImgFound toSize:CGSizeMake(280.0, 300.0)];
dispatch_sync(dispatch_get_main_queue(), ^{
UILabel *dtTimeLabel = (UILabel *)[cell viewWithTag:3];
NSDateFormatter *dtFormat = [[NSDateFormatter alloc]init];
[dtFormat setDateFormat:@"MM-dd-yyyy HH:mm"];
[dtFormat setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:-18000]];
NSString *createdDtString = [dtFormat stringFromDate:createdDt];
dtTimeLabel.text = [NSString stringWithFormat:@"Received on: %@",createdDtString];
[[cell imageView] setImage:newImg];
[cell setNeedsLayout];
}
return cell;
}
在
cellforrowatinexpath
方法中
UIImage *image = [imagesArray objectAtIndex:indexPath.row];
if (image) {
UIImageView *imageView = [[UIImageView alloc] initWithFrame:yourImageViewFrame];//create desired Frame
imageView.image = image;
[cell addSubview:imageView];
} else {
UILabel *label = [[UILabel alloc] initWithFrame:yourLabelFrame];//create desired frame
label.text = @"No Image";
[cell addSubview:label];
}
从服务器加载完图像后,调用
[tableView reloadData]代码>我可以看到问题所在,并可以告诉您解决此问题的正确步骤
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = @"Cell";
UITableViewCell *cell = [tableView
dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil)
{
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
lblOne = [[UILabel alloc]init];
lblOne.tag = 1;
lblTwo = [[UILabel alloc]init];
lblTwo.tag = 2;
lblThree = [[UILabel alloc]init];
lblThree.tag = 3;
lblFour = [[UILabel alloc]init];
lblFour.tag = 4;
btnPlayStop = [[UILabel alloc]init];
btnPlayStop.tag = 5;
// Perform addition functions ( your requirements )
[cell.contentView addSubview:lblOne];
[cell.contentView addSubview:lblTwo];
[cell.contentView addSubview:lblThree];
[cell.contentView addSubview:lblFour];
[cell.contentView addSubview:btnPlayStop];
}
else
{
lblOne = (UILabel*)[cell.contentView viewWithTag:1];
lblTwo = (UILabel*)[cell.contentView viewWithTag:2];
lblThree = (UILabel*)[cell.contentView viewWithTag:3];
lblFour = (UILabel*)[cell.contentView viewWithTag:4];
btnPlayStop = (UILabel*)[cell.contentView viewWithTag:5];
// AND SO ON ...
}
// SET THE VALUES HERE FOR YOUR CONTENT VALUES
return cell;
}
您需要使用动态内容视图创建单元格。
尝试上面的代码段,并根据您自己的修改..如果(cell==nil){cell=[[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];},我是否应该将其包含在其中或者将其置于循环之外?这将是cellForRowAtIndexPath
方法的开始。您不应该调用cellForRowAtIndexPath
方法获取图像,请在其他地方抓取图像,然后重新加载tableView。我们将尝试一下。谢谢你抽出时间。