Question

我正在尝试创建一个弹出窗口，以通知用户操作成功。它应该可以看到几秒钟，然后自行消失。为此，我创建了一个继承自Form的表单，并将ShowWithoutActivation属性设置为true，还创建了一个静态类来控制其构造和操纵其不透明度。

问题在于创建新表单时，它具有正确的大小和初始不透明度，但完全空白。唯一的子控件，没有显示停靠的（填充）标签。我在设计器中设置的Background / Foreground Color属性似乎也被默认值所忽略。窗体会按预期淡入淡出和关闭。

表格本身：

public partial class TempForm : Form
{
    protected override bool ShowWithoutActivation
    {
        get { return true; }
    }

    public TempForm(string message)
    {
        InitializeComponent();
        messageLabel.Text = message;
    }

    private TempForm() { }

}

创建它的静态类：

public static class FadeAwayNotifier
{

    public static void DisplayFadeNotification(Point parentLocation, string message)
    {
        Task t = Task.Factory.StartNew(() =>
        {
            int fadeDelay = 2000;
            int animationLength = 1000;
            int threadRestLength = 20;

            Form popUp = buildForm(parentLocation, message);
            popUp.Show();

            int opacityIncrements = (animationLength / threadRestLength);
            double opacityDecrementAmount = popUp.Opacity / opacityIncrements;

            Thread.Sleep(fadeDelay);

            for (int i = 0; i < opacityIncrements; i++)
            {
                Thread.Sleep(threadRestLength);
                popUp.Opacity -= opacityDecrementAmount;
            }

            popUp.Close();
        });

    }

    private static Form buildForm(Point startLocation, string text)
    {
        TempForm returnForm = new TempForm(text);

        returnForm.Location = startLocation;
        returnForm.messageLabel.Text = text;
        returnForm.BackColor = Color.Black;
        returnForm.ForeColor = Color.White;

        return returnForm;
    }

}

并且，如果有帮助，请参见以下TempForm的设计器代码：

/// <summary>
    /// Required designer variable.
    /// </summary>
    private System.ComponentModel.IContainer components = null;

    /// <summary>
    /// Clean up any resources being used.
    /// </summary>
    /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
    protected override void Dispose(bool disposing)
    {
        if (disposing && (components != null))
        {
            components.Dispose();
        }
        base.Dispose(disposing);
    }

    #region Windows Form Designer generated code

    /// <summary>
    /// Required method for Designer support - do not modify
    /// the contents of this method with the code editor.
    /// </summary>
    private void InitializeComponent()
    {
        this.messageLabel = new System.Windows.Forms.Label();
        this.SuspendLayout();
        // 
        // messageLabel
        // 
        this.messageLabel.BackColor = System.Drawing.Color.Black;
        this.messageLabel.Dock = System.Windows.Forms.DockStyle.Fill;
        this.messageLabel.Font = new System.Drawing.Font("Cambria", 14.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
        this.messageLabel.ForeColor = System.Drawing.Color.White;
        this.messageLabel.Location = new System.Drawing.Point(0, 0);
        this.messageLabel.Name = "messageLabel";
        this.messageLabel.Size = new System.Drawing.Size(254, 81);
        this.messageLabel.TabIndex = 0;
        this.messageLabel.Text = "Message";
        this.messageLabel.TextAlign = System.Drawing.ContentAlignment.MiddleCenter;
        // 
        // TempForm
        // 
        this.AutoScaleDimensions = new System.Drawing.SizeF(9F, 19F);
        this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
        this.BackColor = System.Drawing.Color.Black;
        this.ClientSize = new System.Drawing.Size(254, 81);
        this.Controls.Add(this.messageLabel);
        this.Font = new System.Drawing.Font("Cambria", 12F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
        this.ForeColor = System.Drawing.Color.White;
        this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.None;
        this.Margin = new System.Windows.Forms.Padding(4, 4, 4, 4);
        this.Name = "TempForm";
        this.Opacity = 0.8D;
        this.StartPosition = System.Windows.Forms.FormStartPosition.Manual;
        this.Text = "tempForm";
        this.TopMost = true;
        this.ResumeLayout(false);

    }

    #endregion

    public System.Windows.Forms.Label messageLabel;

对于那些询问如何调用该方法的人：

private void btnUpdate_Click(object sender, EventArgs e)
    {
        Cursor.Current = Cursors.WaitCursor;

        /* Input validation here */

        if (cmbBox.SelectedValue != null)
        {
             updateMethod(a, b....out errorMessage);

            if (String.IsNullOrEmpty(errorMessage))
                       FadeAwayNotifier.DisplayFadeNotification(this.Location, "Rule successfully updated");

        }
        else
            MessageBox.Show("A selection must be made in order to update");

        Cursor.Current = Cursors.Default;
    }

我进行了搜索，但没有发现任何与情况有关的信息。不过，如果我错过了一些事情，我很乐意得到纠正。

为什么创建的表单完全空白？

Answer 1

您的表单为空，因为您试图将其显示在Task.Factory.StartNew()内。

Task.Factory.StartNew()在其内部异步运行代码，由于某种原因，这是form.Show()方法的问题。

解决方案是使用Task t = Task.Factory.StartNew(...而不是Task t = new Tast(....，然后在创建任务后使用t.RunSynchronously()运行它。这样就可以了。

我如何显示临时表格是

创建临时表单（通过vs解决方案资源管理器）创建新的空白winform

添加这样的代码：

public partial class TempForm : Form
{
    System.Windows.Forms.Timer t = new System.Windows.Forms.Timer();
    double seconds = 3;

    public TempForm(int secs, string text)
    {
        InitializeComponent();

        //Custom property to dock it to down right to the screen
        Rectangle workingArea = Screen.GetWorkingArea(this);
        this.Location = new Point(workingArea.Right - Size.Width, workingArea.Bottom - Size.Height);

        t = new System.Windows.Forms.Timer();
        this.seconds = (secs != 0) ? secs : this.seconds;
        richTextBox1.Text = text;
    }

    private void TempForm_Load(object sender, EventArgs e)
    {
        t.Interval = (int)(seconds * 1000);
        t.Tick += new EventHandler(CloseForm);
        t.Start();
    }

    private void CloseForm(object sender, EventArgs e)
    {
        this.Close();
        this.Dispose();
    }

    public static void Show(int seconds, string text)
    {
        TempForm tf = new TempForm(seconds, text);
        tf.Show();
    }
}

要调用它，只需使用TempForm.Show(10, "SomeText");

还要使其看起来更好（不像标准形式），所以看起来像这样：

以编程方式创建的表单为空白

1 个答案: