C# 在C中从PictureBox中删除图像#

如何在用户按“删除”键时从图片框中删除图像…我找不到PB的任何按键或按键事件

    private void topRight_pbx_MouseClick(object sender, MouseEventArgs e)
          {
           imgSelected=true;

           //need to accept "delete"key from keyboard?

           topRight_pbx.Image = null;
            topRFile = "";

           }

---

这是因为

PictureBox

控件永远无法获得焦点，而非焦点控件不接收键盘输入事件。

    private void topRight_pbx_MouseClick(object sender, MouseEventArgs e)
          {
           imgSelected=true;

           //need to accept "delete"key from keyboard?

           topRight_pbx.Image = null;
            topRFile = "";

           }

如图所示，

KeyDown

事件（以及与键盘输入相关的其他事件）被标记为

[BrowsableAttribute（false）]

，因为它们不能按预期工作。您的代码不打算订阅它们

    private void topRight_pbx_MouseClick(object sender, MouseEventArgs e)
          {
           imgSelected=true;

           //need to accept "delete"key from keyboard?

           topRight_pbx.Image = null;
            topRFile = "";

           }

它类似于

标签

控件，您可以查看它，但它不可选择，也无法获得焦点

    private void topRight_pbx_MouseClick(object sender, MouseEventArgs e)
          {
           imgSelected=true;

           //need to accept "delete"key from keyboard?

           topRight_pbx.Image = null;
            topRFile = "";

           }

---

您需要为用户找到另一种方式来表示他想要删除当前显示在

PictureBox

控件中的图像。

将您的imgSelected更改为类似以下内容：

    private void topRight_pbx_MouseClick(object sender, MouseEventArgs e)
          {
           imgSelected=true;

           //need to accept "delete"key from keyboard?

           topRight_pbx.Image = null;
            topRFile = "";

           }

private PictureBox picSelected = null;

在picturebox上，单击将此变量设置为发件人：

    private void topRight_pbx_MouseClick(object sender, MouseEventArgs e)
          {
           imgSelected=true;

           //need to accept "delete"key from keyboard?

           topRight_pbx.Image = null;
            topRFile = "";

           }

picSelected = (PictureBox)sender;

然后在窗体或具有焦点的控件的键下，运行图像删除代码 （表格示例）：

    private void topRight_pbx_MouseClick(object sender, MouseEventArgs e)
          {
           imgSelected=true;

           //need to accept "delete"key from keyboard?

           topRight_pbx.Image = null;
            topRFile = "";

           }

---

我在我的一个项目中遇到了类似的问题。我通过添加一个屏幕外文本框解决了这个问题。单击某些控件时，我会将焦点放在文本框上，并使用文本框处理键盘输入

    private void topRight_pbx_MouseClick(object sender, MouseEventArgs e)
          {
           imgSelected=true;

           //need to accept "delete"key from keyboard?

           topRight_pbx.Image = null;
            topRFile = "";

           }

PicureBox SelectedImage=null;

void Image_Click(object sender,...)
{
  SelectedImage=(PictureBox)sender;
  FocusProxy.Focus();
}

void FocusProxy_KeyDown(...)
{
  if(e.KeyData==...)
  {
       SelectedImage.Image=null;
       e.Handled=true;
  }
}

---

另一种方法是： 如果要在pictureBox上绘图，并且要清除它，请执行以下操作：

    private void topRight_pbx_MouseClick(object sender, MouseEventArgs e)
          {
           imgSelected=true;

           //need to accept "delete"key from keyboard?

           topRight_pbx.Image = null;
            topRFile = "";

           }

Graphics g = Graphics.FromImage(this.pictureBox1.Image);
g.Clear(this.pictureBox1.BackColor);

之后，可以再次在控件上绘制

    private void topRight_pbx_MouseClick(object sender, MouseEventArgs e)
          {
           imgSelected=true;

           //need to accept "delete"key from keyboard?

           topRight_pbx.Image = null;
            topRFile = "";

           }

---

当然，如果你有多个

PictureBox

控件，你仍然需要一些外部方法来指示选择了哪一个，以免用户无意中删除了错误的图像。我忘记了细节，但这种方法有一些问题。我认为这是因为在某些情况下表单没有获得关键事件。当然，你只想在选中图像时删除图像，而不是用户只想删除字符的其他文本控件。@Jorge:我的表单中有4个pic框，这是处理所选图像的删除还是我需要显式处理？@Sisya:如果你将相同的代码放在所有4个pic框中单击（通过转到同一个单击处理程序或复制粘贴）它将适用于所有这些操作，只删除用户最后单击的一个。@CodeInChaos:添加代码以聚焦带有keydown事件的隐藏文本框可以解决此问题；）我不明白任何人如何期望它在多个PictureBox中正常工作，或者为什么这是公认的答案。问题中为

MouseClick

事件提供的代码已删除图像。显然，关键是要用键盘。但是，当用户按下键盘上的Del键时，您将如何检测用户试图在哪个

PictureBox

中删除图像？

    private void topRight_pbx_MouseClick(object sender, MouseEventArgs e)
          {
           imgSelected=true;

           //need to accept "delete"key from keyboard?

           topRight_pbx.Image = null;
            topRFile = "";

           }