问题描述

我正在尝试解决我之前提出的这个问题:Populate SourceList inXamarin.Mac 应用程序

I am trying to find a solution to this question I asked earlier: Populate SourceList in Xamarin.Mac app

我目前正在尝试实现 NSOutlineViewDelegate 的 GetView 方法，看看是否会在我拥有的 OutlineView 中创建一些文本.

I am currently trying to implement the GetView method of the NSOutlineViewDelegate to see if that may create some text in the OutlineView I have.

但我一直在尝试向 NSView 对象添加内容.当我查看示例 OutlineView(将其拖到窗口上时默认获得的)时，每个项目都有一个 TableCellView.结构看起来像这样(首先是标题，然后是常规项):

But I am stuck at trying to add stuff to the NSView object. When I look at the example OutlineView (the one you get by default when you drag it onto your window), there's a TableCellView for each item. The structure looks like this (header first, then regular item):

Table Cell View
  Static Text - HEADER CELL
    Text Field Cell - HEADER CELL

Table Cell View
  Image View
    Image Cell
  Static Text - Table View Cell
    Text Field Cell - Table View Cell

到目前为止，我的方法如下所示:

So far my method looks like this:

public override NSView GetView (NSOutlineView outlineView, NSTableColumn tableColumn, NSObject item)
{
    var navigation = item as Navigation;
    var cell = new NSTableCellView();

    if (navigation.IsHeader) {
    } else {
    }

    return cell;
}

我首先猜测标题是什么，例如，我创建了一个 NSTableHeaderCell 并将 StringValue 属性设置为 navigation.Name.但我不知道如何将它作为一个孩子添加到我的 NSTableViewCell.

My first guess what that for the header, for example, I create a NSTableHeaderCell and set the StringValue property to navigation.Name. But I have no idea how to then add it as a child to my NSTableViewCell.

或者我是在用完全错误的方式来解决这个问题吗?我对 Mono 和 Xamarin 非常陌生(只使用 WPF 和 XAML 完成过 C# 和 Visual Studio)，而且我以前从未在 Objective-C 中进行过编程(所以我花了一段时间才弄清楚方法/类的奇怪语法).

Or am I going about this the completely wrong way? I am very new to Mono and Xamarin (have only done C# and Visual Studio using WPF and XAML) and I have never before done programming in Objective-C before (so it took me a while to figure out the weird syntax for methods/classes).

推荐答案

您会在 XCode 中看到 Table Cell View 对象有一个您可以设置的标识符".就我而言，我有HeaderCell"和DataCell".

You'll see in XCode that the Table Cell View objects have an 'Identifier' that you can set. In my case I have 'HeaderCell' and 'DataCell'.

我的代码如下所示:

public override NSView GetView(NSOutlineView outlineView, NSTableColumn tableColumn, NSObject item)
{
    if(IsGroupItem(outlineView, item))
    {
        return outlineView.MakeView("HeaderCell", this);
    }

    return outlineView.MakeView("DataCell", this);
}

这将创建 XCode 中定义的 TableCellView 的适当实例.

This will create an appropriate instance of the TableCellView defined in XCode.

就我而言，我使用 Cocoa 绑定而不是数据源，因此我的视图会自动填充数据.这可能是您想要研究的一种方法，因为它更接近于 WPF/XAML 的数据绑定方式.然而，它有一个陡峭的学习曲线并且难以调试(如 WPF/XAML 数据绑定！).

In my case, I use Cocoa bindings rather than a data source, so my views get populated with data automatically. This may be an approach you want to investigate because it is much closer to the WPF/XAML way of databinding. However, it has a steep learning curve and is difficult to debug (like WPF/XAML databinding!).

您可以访问它的子视图并适当地设置它们，而不是简单地返回单元格.比如:

Instead of simply returning the cell, you could access it's subviews and set them up appropriately. Something like:

var dataView = outlineView.MakeView("DataCell", this);
((NSImageView)dataView.Subviews[0]).Image = // assign an image
((NSTextField)dataView.Subviews[1]).StringValue = // assign your text
return dataView;

(注意:我只是从头顶输入的，它可能无法按原样工作 - 但希望你明白)

(Note: I just typed that from the top of my head, it may not work as-is - but hopefully you get the idea)

这篇关于在 Xamarin Studio 中以编程方式创建 NSView的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持编程学习网！