objective-c - 基于 View “Source List” NSOutlineView 不显示项目的图标和标题

Question

将 NSOutlineView cell-based 更改为 view-based 后，它不再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@“Root Folder”)和路径类。因为，现在以前基于 View 的方法只在“HeaderCell”或“DataCell”中显示枚举项，当我尝试为“HeaderCell”分配某个值时，应用程序崩溃了。你能帮我解决这个问题吗？

Answer 1

要显示项目的标题和图标，只需更改此方法即可

- (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;
    }
}