目标c：将委托移交给其他班级

发布于 2024-11-28 11:36:59 字数 1189 浏览 0 评论 0原文

我在这里遇到了一个问题。我有一个协议，它规定了一个方法，该方法返回我的表视图的数据源。数据源由一个类生成，用于 3 个表视图。如果您点击一个单元格，您将进入下一个具有不同来源的表格视图，依此类推（我想您明白了）。

对于第一个表视图，一切正常，但是当我将删除移交给下一个表视图时，我仍然没有获得第二个表视图的数据源。我是否必须在某个时刻释放委托？如果必须的话，当点击导航栏按钮项时，如何取回它......？

如果你有什么想法请告诉我。

编辑：

if ([Where isEqualToString:@"System"])
{
    if ([exchangeDelegate respondsToSelector:@selector(getNewDataSourceForSystem:)]) 
    {
        [exchangeDelegate getNewDataSourceForSystem: [controlDelegate setBranchNavigation:What]];
    }
}
    else if ([Where isEqualToString:@"User"])
    {
        if ([exchangeDelegate respondsToSelector:@selector(getNewDataSourceForUser:)]) 
        {
            [exchangeDelegate getNewDataSourceForUser: [controlDelegate setLeafNavigation:What]];
        }
}
if ([exchangeDelegate respondsToSelector:@selector(getNewDataSourceForCostumer:)]) 
{
    [exchangeDelegate getNewDataSourceForCostumer: [controlDelegate setRootNavigation]];
}

每个 respondToSelector 进入不同的类。

编辑： * 由于未捕获的异常“NSInvalidArgumentException”而终止应用程序，原因：“-[Costumers getNewDataSourceForSystem:]: 无法识别的选择器发送到实例 0x8a3b0e0”

这就是当我省略 respondsToSelector 时得到的异常：@选择器。

原文

I am here confronted with a certain problem. I have a protocol which states a method, that returns the datasource for my tableviews. The datasources are generated by one class, for 3 tableviews. If you tap on one cell, you get to the next tableview with a different source and so on (I think you get the point).

Everything works fine for the first tableview, but as I hand over the deletage to the next tableview I still do not get the datasource for the second. Do I have to release the delegate at a certain point? And if I have to, how do I get it back, when the navigationbarbuttonitem is tapped on...?

Tell me if you have any ideas.

EDIT:

if ([Where isEqualToString:@"System"])
{
    if ([exchangeDelegate respondsToSelector:@selector(getNewDataSourceForSystem:)]) 
    {
        [exchangeDelegate getNewDataSourceForSystem: [controlDelegate setBranchNavigation:What]];
    }
}
    else if ([Where isEqualToString:@"User"])
    {
        if ([exchangeDelegate respondsToSelector:@selector(getNewDataSourceForUser:)]) 
        {
            [exchangeDelegate getNewDataSourceForUser: [controlDelegate setLeafNavigation:What]];
        }
}
if ([exchangeDelegate respondsToSelector:@selector(getNewDataSourceForCostumer:)]) 
{
    [exchangeDelegate getNewDataSourceForCostumer: [controlDelegate setRootNavigation]];
}

each respondToSelector goes to a different class.

EDIT:
* Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[Costumers getNewDataSourceForSystem:]: unrecognized selector sent to instance 0x8a3b0e0'

Thats what I get as an exception when I leave out respondsToSelector:@selector.

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绅刃 2024-12-05 11:36:59

您是否已调用 -[UITableView reloadData] 来通知其当前状态失效？

您是否重载了委托 setter 方法，以便根据需要获取和设置新的数据源和委托？大概是这样的：

-(void)setDelegate:(id<MYDelagate>)delegate;
{
    myTableView.dataSource = [delegate tableViewDataSource];
    myTableView.delegate = [delegate tableViewDelegate];
    _delegate = delegate;
}

Have you called -[UITableView reloadData] to inform it about invalidation of its current state?

And have you overloaded you delegate setter method in order to also fetch and set the new datasource and delegate as needed? Probably something like this:

-(void)setDelegate:(id<MYDelagate>)delegate;
{
    myTableView.dataSource = [delegate tableViewDataSource];
    myTableView.delegate = [delegate tableViewDelegate];
    _delegate = delegate;
}

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