objective-c - 基于视图的“源列表”NSOutlineView 不显示项目的图标和标题

Question

将 NSOutlineView cell-based 更改为 view-based 后，它不会显示文件系统树的图标和标题。这是我的代码：

- (void)outlineView:(NSOutlineView *)outlineView willDisplayCell:(id)cell forTableColumn:(NSTableColumn *)tableColumn item:(id)item {
    if ([[tableColumn identifier] isEqualToString:@"name"])
        return [(ImageAndTextCell *)cell setTextFieldImage:[item icon]];
}

- (id)outlineView:(NSOutlineView *)outlineView objectValueForTableColumn:(NSTableColumn *)tableColumn byItem:(id)item {
    return [((ConstructorFSEntity *)item) title];
}

- (NSView *)outlineView:(NSOutlineView *)outlineView viewForTableColumn:(NSTableColumn *)tableColumn item:(id)item {
    if ([item isKindOfClass:[FSEntity class]]) {
        return [outlineView makeViewWithIdentifier:@"HeaderCell" owner:self];
    } else {
        return [outlineView makeViewWithIdentifier:@"DataCell" owner:self];
    }
}

我还有一个问题。如何将枚举项（文件系统项的数组）放入单元格“DataCell”，并将“HeaderCell”声明为父文件夹（组）并为其分配标题（例如，@“根文件夹”）和路径班上。因为，现在以前的基于视图的方法，仅在“HeaderCell”或“DataCell”中显示枚举项，当我尝试为“HeaderCell”分配某个值时，应用程序崩溃。你能帮我解决这个问题吗？

Answer 1

要显示项目的标题和图标，您只需更改此方法

- (NSView *)outlineView:(NSOutlineView *)outlineView viewForTableColumn:(NSTableColumn *)tableColumn item:(id)item

如下：

- (NSView *)outlineView:(NSOutlineView *)outlineView viewForTableColumn:(NSTableColumn *)tableColumn item:(id)item {
    if (![item isKindOfClass:[FSEntity class]]) {
        return [outlineView makeViewWithIdentifier:@"HeaderCell" owner:self];
    } else {
        NSTableCellView *cellView = [outlineView makeViewWithIdentifier:@"DataCell" owner:self];
        [(ImageAndTextCell *)cellView.textField.cell setTextFieldImage:[item icon]];
        cellView.textField.stringValue = [((FSEntity *)item) title];
        return cellView;
    }
}