DataGridView.SelectedRows.Count always = 0

Question

我在我的應用程序中有一個datagridview。我希望能夠選擇一行或多行，然後單擊鼠標右鍵並獲取上下文菜單。上下文菜單中的選項會對選定的行執行某些操作，例如隱藏它們。對於datagridview，我有multiselect = true和selectionmode = fullrowselect。出於某種原因，datagridview.selectedrows.count始終爲0.爲什麼會這樣呢？這裏是代碼...

private void Form1_Load(object sender, EventArgs e) 
    { 
     Image img = null; 
     contextMenuStrip1.Items.Add("Hide selected", img, new System.EventHandler(contextMenuStrip1_Click)); 
     contextMenuStrip1.Items.Add("Unhide all", img, new System.EventHandler(contextMenuStrip1_Click)); 
     dataGridView1.ContextMenuStrip = contextMenuStrip1; 
    } 

    private void contextMenuStrip1_Click(object sender, EventArgs e) 
    { 
     switch (sender.ToString().Trim()) 
     { 
      case "Hide selected": 
       //Necessary because a row with the current cell cannot be hidden. 
       dataGridView1.CurrentCell = null; 
       int count = dataGridView1.SelectedRows.Count; 
       foreach (DataGridViewRow row in dataGridView1.SelectedRows) 
       { 
        row.Visible = false; 
       } 
       break; 

      case "Unhide all": 
       foreach (DataGridViewRow row in dataGridView1.Rows) 
       { 
        row.Visible = true; 
       } 
       break; 
     } 

    } 

Answer 1

好吧，所以我已經設置了一個快速項目來重現你的問題。問題是你將dataGridView1.CurrentCell設置爲null。當你這樣做時，它會清除網格視圖中的選定行。我注意到你在那裏有一個評論，它必須在那裏。我並不完全確定所有的邏輯和業務領域，但你需要找到另一種方法。有了這個代碼，我沒有問題得到選定行（S）：

switch (sender.ToString().Trim()) 
    { 
     case "Hide selected": 
      int count = dataGridView1.SelectedRows.Count; 
      foreach (DataGridViewRow row in dataGridView1.SelectedRows) 
      { 
       row.Visible = false; 
      } 
      break; 

     case "Unhide all": 
      foreach (DataGridViewRow row in dataGridView1.Rows) 
      { 
       row.Visible = true; 
      } 
      break; 
    }