Question

我目前正在尝试检测中心屏幕像素的颜色变化。但不知怎的，它总会返回第一个变化。

我目前的代码：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Drawing.Imaging;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace pixelChange
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        public Color startingColor;

        // Get center pixel color rbg once the form loaded
        private void Form1_Load(object sender, EventArgs e)
        {
            startingColor = GetPixelColor(Screen.PrimaryScreen.Bounds.Width / 2, Screen.PrimaryScreen.Bounds.Height / 2);
        }

        // Timer which calls the GetPixelColor to check for a difference
        private void timer1_Tick(object sender, EventArgs e)
        {
            checkForColorDifference(startingColor);
        }

        // Get pixel color function
        public Color GetPixelColor(int x, int y)
        {
            Bitmap snapshot = new Bitmap(Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height, PixelFormat.Format32bppArgb);

            using (Graphics gph = Graphics.FromImage(snapshot))
            {
                gph.CopyFromScreen(Screen.PrimaryScreen.Bounds.X, Screen.PrimaryScreen.Bounds.Y, 0, 0, Screen.PrimaryScreen.Bounds.Size, CopyPixelOperation.SourceCopy);
            }

            return snapshot.GetPixel(x, y);
        }

        // Function to check if the color of the center pxiel changed
        public void checkForColorDifference(Color start)
        {
            Color starting = start;
            Color currentColor = GetPixelColor(Screen.PrimaryScreen.Bounds.Width / 2, Screen.PrimaryScreen.Bounds.Height / 2);

            if (starting != currentColor)
            {
                MessageBox.Show("Color: " + start + " changed to:" + currentColor.ToString() + ".", "Color change response");
                startingColor = currentColor;
            }
        }

    }
}

到目前为止代码的工作原理：

Form1_Load get触发并公开Color startingColor;得到一个颜色，这是GetPixelColor函数的结果。
计时器在每个刻度线上调用checkForColorDifference函数。
checkForColorDifference函数接受startingColor作为参数并抓取另一种颜色以按以下方式比较颜色：starting.ToString（）！= currentColor.ToString（）
如果颜色不匹配，则会显示一个消息框并显示公共Color startingColor;应该填充存储在Color currentColor中的第二种颜色。

但是代码总会返回相同的错误响应（第一个响应）。我做错了什么？

问题的屏幕截图：https://i.gyazo.com/0162e404a3ecef2820024e4f93678d2a.png

Answer 1

我认为使用ToString（）比较颜色是一个坏主意...显示this答案，知道如何正确地做到这一点：

你必须比较argb值。

Answer 2

禁用计时器，直到您确认显示的消息框。代码将在MessageBox.Show（）行中“停止”，直到您单击“确定”。因此，在单击“确定”之后才会设置新颜色。与此同时，由于相当神秘的winforms逻辑，计时器仍在运行。

    public void checkForColorDifference(Color start)
    {
        Color starting = start;
        Color currentColor = GetPixelColor(Screen.PrimaryScreen.Bounds.Width / 2, Screen.PrimaryScreen.Bounds.Height / 2);

        if (starting != currentColor)
        {
            timer1.Enabled = false;
            MessageBox.Show("Color: " + start + " changed to:" + currentColor.ToString() + ".", "Color change response");
            startingColor = currentColor;
            timer1.Enabled = true;
        }
    }

奖金修复，用于一次性位图：

    public Color GetPixelColor(int x, int y)
    {
        using (Bitmap snapshot = new Bitmap(Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height, PixelFormat.Format32bppArgb))
        using (Graphics gph = Graphics.FromImage(snapshot))
        {
            gph.CopyFromScreen(Screen.PrimaryScreen.Bounds.X, Screen.PrimaryScreen.Bounds.Y, 0, 0, Screen.PrimaryScreen.Bounds.Size, CopyPixelOperation.SourceCopy);

            return snapshot.GetPixel(x, y);
        }
    }

C＃检测中心屏幕像素的颜色变化

2 个答案: