如何检查位图图像是否为空?

本文介绍了如何检查位图图像是否为空?的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

在Form1中，我在构造函数中创建一个新的位图:

In Form1 I create in the constructor a new Bitmap:

public Form1()
{
    InitializeComponent();
    de.pb1 = pictureBox1;
    de.bmpWithPoints = new Bitmap(pictureBox1.Width, pictureBox1.Height);
    de.numberOfPoints = 100;
    de.randomPointsColors = false;
    de.Init();
}

在课堂上，我检查位图是否为空:

In the class I check if the bitmap is null :

if (bmpWithPoints == null)

位图不为null，但也未绘制任何内容.我检查该类是否为空，我想在位图上绘制并设置点.

The bitmap is not null but is also not drawn with anything on it.I check in the class if it's null I want to draw and set points on the bitmap.

if (bmpWithPoints == null)
{
    for (int x = 0; x < bmpWithPoints.Width; x++)
    {
        for (int y = 0; y < bmpWithPoints.Height; y++)
        {
            bmpWithPoints.SetPixel(x, y, Color.Black);
        }
    }
    Color c = Color.Red;
    for (int x = 0; x < numberOfPoints; x++)
    {
        for (int y = 0; y < numberOfPoints; y++)
        {
            if (randomPointsColors == true)
            {
                c = Color.FromArgb(
                    r.Next(0, 256),
                    r.Next(0, 256),
                    r.Next(0, 256));
            }
            else
            {
                c = pointsColor;
            }
            bmpWithPoints.SetPixel(r.Next(0, bmpWithPoints.Width),
                r.Next(0, bmpWithPoints.Height), c);
        }
    }
}
else
{
    randomPointsColors = false;
}

也许问题不应该是图像为空或为空，我不确定如何调用它.也许只是一个新形象.但是我想检查一下，如果新的位图是(空的)没有在其上绘制任何东西，然后设置像素(点).

Maybe the question should not be if the image is empty or null, I'm not sure how to call it. Maybe just a new image. But i want to check that if the new bitmap is (empty) nothing drawn on it then set the pixels(points).

推荐答案

您可以创建一种检查图像像素的方法.作为一种选择，您可以使用 LockBits 方法将位图字节转换为字节数组并使用它们:

You can create a method which checks image pixels. As an option, you can use LockBits method to get bitmap bytes into a byte array and use them:

bool IsEmpty(Bitmap image)
{
    var data = image.LockBits(new Rectangle(0,0, image.Width,image.Height),
        ImageLockMode.ReadOnly, image.PixelFormat);
    var bytes = new byte[data.Height * data.Stride];
    Marshal.Copy(data.Scan0, bytes, 0, bytes.Length);
    image.UnlockBits(data);
    return bytes.All(x => x == 0);
}

这篇关于如何检查位图图像是否为空?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！

Lockbits