如何使用TreeView_SetItem来改变lParam?

时间:2017-02-13 22:48:01

标签: c++ winapi treeview

我正在尝试使用TreeView_SetItem设置lParam,但它无效。以下测试代码使用TreeView_GetItem显示在使用TreeView_SetItem设置后lParam未更改。

targetItem之前已设为HTREEITEMTreeView_SetItemTreeView_GetItem都返回true,因此没有错误。

// targetitem has been set to an HTREEITEM which has an lParam equal to 1.
// I want to change it to 17
//
TVITEM tvItem = { 0 };
tvItem.mask = TVIF_PARAM | TVIF_HANDLE;
tvItem.hItem = targetItem;
tvItem.lParam = (LPARAM)17;
bool test1 = TreeView_SetItem(hWnd, targetItem, &tvItem);  // returns true

TVITEM tvi = { 0 };
tvi.mask = TVIF_PARAM | TVIF_HANDLE;
tvi.hItem = targetItem;
bool test2 = TreeView_GetItem(hWnd, &tvi);  // returns true
//
// tvi.lParam is unchanged after setting (still = 1, expecting 17)

1 个答案:

答案 0 :(得分:1)

好的发现了。 TreeView_SetItem应该只有2个参数而不是3个。不知道它为什么不会抛出错误。

bool test1 = TreeView_SetItem(hWnd, &tvItem);