c# - 如何在 C# 代码中添加占位符？

Question

如何在 c# 代码中添加占位符？我想以我的形式显示 DateTime.Now。

<div class="col-md-10">
  @Html.EditorFor(model => model.Date,  new { htmlAttributes = new { @class = "form-control"  } })
  @Html.ValidationMessageFor(model => model.Date, "", new { @class = "text-danger" })
</div>

Answer 1

你试过 -

  @Html.EditorFor(model => model.Date, new { placeholder =  DateTime.Now.ToString("MM/dd/yyyy")})

Answer 2

/** Here is how I did it in my code. I had a richtexBox5 that I needed to add QTY placeholder. So what did was, inside public form i did the following */
  public Form1()
        {
            InitializeComponent();

         richTextBox5.Text = "QTY";// set text you want to show

         if (richTextBox5.Text == "QTY")
            {
             richTextBox5.ForeColor = Color.LightGray;// set color
           }
        }

/**now make this function which will listen to mouse click  in wherever part you want*/
 private void richTextBox5_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
        {           
            if(richTextBox5.Text=="QTY") // check what is in that textbox
            {
                richTextBox5.Text = "";// set it to null 
                richTextBox5.ForeColor = Color.Black;// change color
            }      
        }