IDE:Visual Studio 2010 Express
Lib:Emgu CV 2.2
等级:初学者
单击PictureBox时我将相机设为ON,反之亦然,但它给出了错误:
Object reference not set to an instance of an object
这里是事件处理程序:
private void pictureBoxCapture_Click(object sender, EventArgs e)
{
try
{
if (Clicked == true) //i dont know how to make it right
{
Application.Idle -= ProcessFrame;
}
else
{
Application.Idle += ProcessFrame;
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
来自:
private void ProcessFrame(object sender, EventArgs e)
{
//Cap = new Emgu.CV.Capture();
ImageFrame = Cap.QueryFrame();
pictureBoxCapture.Image = ImageFrame.ToBitmap();
}
如何设置if else参数,有什么建议吗?
答案 0 :(得分:2)
创建一个类级布尔变量,然后在PictureBox的click事件中切换它。
public partial class Form1 : Form
{
bool Clicked; //Create this Class level variable to be used in your handler
public Form1()
{
InitializeComponent();
}
private void pictureBoxCapture_Click(object sender, EventArgs e)
{
Clicked =! Clicked; //Toggle your Boolean here
try
{
if (Clicked)
{
Application.Idle -= ProcessFrame;
FaceDetect();
}
else
{
Application.Idle += ProcessFrame;
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
}
答案 1 :(得分:1)
我希望您的错误不会被图片框点击事件引发,而是ProcessFrame()
事件。在删除Application.Idle -= ProcessFrame;
之后,它会有一次触发的习惯,但是在事件参数中没有图像可以使用。而是将此代码用作ProcessFrame()
事件:
private void ProcessFrame(object sender, EventArgs e)
{
//Cap = new Emgu.CV.Capture();
ImageFrame = Cap.QueryFrame();
//Look for image content if null do nothing
if(ImageFrame != null)
{
pictureBoxCapture.Image = ImageFrame.ToBitmap();
//do any other operations on the image
}
}
干杯,
克里斯