如何在目标c中使用xmpp框架显示用户头像图像？

Question

我正在使用XMPPFramework为iPhone创建一个聊天应用程序。 我想在UITableView中显示用户名和照片的用户列表，为此我正在使用

NSData *photoData = [[[self appDelegate] xmppvCardAvatarModule] photoDataForJID:user.jid];
if (photoData != nil)
    cell.imageView.image = [UIImage imageWithData:photoData];
else
    cell.imageView.image = [UIImage imageNamed:@"blank_image~iPhone.png"];

但它总是返回零。

请帮忙..

Answer 1

NSData *photoData = UIImagePNGRepresentation([[[self appDelegate] xmppvCardAvatarModule] photoDataForJID:user.jid]);

if (photoData)
    cell.imageView.image = [UIImage imageWithData:photoData];
else
    cell.imageView.image = [UIImage imageNamed:@"blank_image~iPhone.png"];

Answer 2

这段代码工作正常。

photoDataForJID方法返回NSData。

NSData *avtarData = [[[self appDelegate] xmppvCardAvatarModule] photoDataForJID:user.jid];

if (avtarData)
    cell.imageView.image = [UIImage imageWithData:photoData];
else
    cell.imageView.image = [UIImage imageNamed:@"blank_image~iPhone.png"];

Answer 3

dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0ul);
    dispatch_async(queue, ^{

             NSData *imgData = UIImagePNGRepresentation([[[self appDelegate] xmppvCardAvatarModule] photoDataForJID:user.jid]);
            dispatch_async(dispatch_get_main_queue(), ^{


if (imgData)
    cell.imageView.image = [UIImage imageWithData:imgData];
else
    cell.imageView.image = [UIImage imageNamed:@"default_user.png"];
            });
        });