將Windows窗體轉換為WPF

Question

以下是我在Windows Forms應用程序中的代碼的一部分，考慮到這一點，如何將其轉換為this.Controls不可用：

public Form1()
        {
            InitializeComponent();
            foreach (TextBox tb in this.Controls.OfType<TextBox>())
            {
                tb.Enter += textBox_Enter;
            }
        }

        void textBox_Enter(object sender, EventArgs e)
        {
            focusedTextbox = (TextBox)sender;
        }

private TextBox focusedTextbox = null;

private void button1_Click (object sender, EventArgs e)
        {
            if (focusedTextbox != null)
            {
                focusedTextbox.Text += "1";

            }
        }

Answer 1

在根元素（很可能是Window本身）上偵聽PreviewGotKeyboardFocus並記錄e.NewFocus參數。 預覽事件使可視化樹冒出氣泡，因此任何在父控件中公開一個控件的控件都將觸發它（請參閱路由事件 ）。

事件處理程序變為：

    private void OnGotFocusHandler(object sender, KeyboardFocusChangedEventArgs e)
    {
        var possiblyFocusedTextbox = e.NewFocus as TextBox;
        //since we are now receiving all focus changes, the possible textbox could be null
        if (possiblyFocusedTextbox != null)
            focusedTextbox = possiblyFocusedTextbox;
    }