Why is a textbox's focused property not true when it is in focus?

Question

Although I've made sure that one of these text boxes are indeed in focus, the Focused property is false for each one. Why?

private TextBox GetTextboxInFocus()
    {
        if (txtFeet.Focused)
        {
            return txtFeet;
        }
        if (txtInches.Focused)
        {
            return txtInches;
        }
        if (txtSixteenths.Focused)
        {
            return txtSixteenths;
        }
        return null;
    }

Answer 1

问题在于你调用/调用......

我已经为你理解了一个示例代码......

    private void CheckFocusAndShowResults(string throughControl)
    {
        var result = GetTextboxInFocus();

        if (result == null)
        {
            label1.Text = "No textbox is focused.";
        }
        else
        {
            label1.Text = string.Format("textbox {0} is focused and {1} is called.", result.Name, throughControl);
        }
    }

尝试通过按钮调用时......没有文本框聚焦。

然后我为文本框添加了两个事件以验证焦点......

    private void textBox1_Click(object sender, EventArgs e)
    {
        CheckFocusAndShowResults("Texbox Click Event");
    }

    private void textBox1_Leave(object sender, EventArgs e)
    {
        CheckFocusAndShowResults("Texbox Leave Event");
    }

单击textbox1时，会触发第一个事件，并且textbox1会聚焦（请参阅标签）

当离开textbox1时，第二个事件被触发，textbox1被聚焦，同时评估条件......虽然目前焦点是textbox2（用蓝色轮廓突出显示）。

所以你可以按照我所示的点击或离开事件来调用。