xcode 仅在 reloadData 完成后调用函数
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Call function only after reloadData has finished
提问by Brandon
I have a tableViewand need to perform a function once the tableViewhas been reloaded. How do I know if reloadDatahas finished? Lets say I have methodA that populates the tableView, and once [tableView1 reloadData]has been completed, I want to call methodB. Can anyone help me with this? I've been searching for hours... Thank you!
我有一个tableView并且需要tableView在重新加载后执行一个功能。我怎么知道是否reloadData已经完成？假设我有填充 的方法A tableView，一旦[tableView1 reloadData]完成，我想调用方法B。谁能帮我这个？我已经找了几个小时了……谢谢！
- (void) methodA
{
NSString *URLa = [NSString stringWithFormat:@"http://www.website.com/page.php?
v1=%@&v2=%@&v3=%@",v1, v2, v3];
NSURL *url = [NSURL URLa];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
(void) [[NSURLConnection alloc] initWithRequest:request delegate:self];
[tableView1 reloadData];
}
回答by Anoop Vaidya
You can add a method/category on UITableView or even subclass UITableView:
您可以在 UITableView 甚至子类 UITableView 上添加方法/类别：
-(void)reloadDataAndWait:(void(^)(void))waitBlock {
[self reloadData];//if subclassed then super. else use [self.tableView
if(waitBlock){
waitBlock();
}
}
And you need to use it as
你需要把它用作
[self.tableView reloadDataAndWait:^{
//call the required method here
}];
回答by Martin R
The problem is that you call reloadDataimmediately after starting the URL request. That does not make sense because the request has not been completed at that point.
问题是您reloadData在启动 URL 请求后立即调用。这是没有意义的，因为此时请求尚未完成。
The correct way would be to call reloadDataand methodBin connectionDidFinishLoading, after you have updated your data source with the response from the URL request. At that point you know if the number of rows is zero or not, and there is no need to waitfor the table view update to complete.
正确的方法是在使用 URL 请求的响应更新数据源后调用reloadData和methodBin connectionDidFinishLoading。此时您就知道行数是否为零，并且无需等待表视图更新完成。
回答by swiftBoy
Once I get updated data from server for my table.
一旦我从服务器为我的表获取更新的数据。
I use following code snip to Hide progress bar when table reload gets complete.
当表重新加载完成时，我使用以下代码片段来隐藏进度条。
[UIView animateWithDuration:0 animations:^{
[your_table_view reloadData];
} completion:^(BOOL finished)
{
//Table reload completed TODO here
//Hide progress bar etc.
}];
