C# 線程獲取/設置控件(TextBox)值

線程讀寫控件需要用委托(delegate)與Invoke/BeginInvoke來進行

參考內容：http://www.cnblogs.com/runner/archive/2011/12/30/2307576.html

1. 獲取TextBox中的值

代碼一：

        public delegate string GetTextBoxCallBack();
        private string GetInputText()
        {
            try
            {
                if (this.txtInput.InvokeRequired)
                {
                    GetTextBoxCallBack gtb = new GetTextBoxCallBack(GetInputText);
                    IAsyncResult ia = txtInput.BeginInvoke(gtb);
                    return (string)txtInput.EndInvoke(ia);  //這里需要利用EndInvoke來獲取返回值
                }
                else
                {
                    return txtInput.Text;
                }
            }
            catch (Exception ex)
            {
                return "";
            }
        }

 代碼二:

        private string GetTextCallBack()
        {
            if (this.txtInput.InvokeRequired)
            {
                string inputTxt = string.Empty;
                this.txtInput.Invoke(new MethodInvoker(delegate { inputTxt = txtInput.Text; }));
                return inputTxt;
            }
            else
            {
                return this.txtInput.Text;
            }
        }

 

2.線程設置TextBox值

代碼一：

        delegate void SetTextBoxCallback(string text);
        private void SetInputText(string text)
        {
            if (this.txtInput.InvokeRequired)
            {
                SetTextBoxCallback d = new SetTextBoxCallback(SetInputText);
                this.Invoke(d, new object[] { text });
            }
            else
            {
                this.txtInput.Text = text;
            }
        }

 代碼二：

string changeTxt = "Change Text";
txtInput.Invoke(new Action<String>(p =>
                {
                    txtInput.Text = changeTxt;
                }), txtInput.Text);