將位圖拆分為位圖數組

Question

請先閱讀標題。 這是主要思想。問題是此C＃代碼的問題在哪里？（沒有編譯或運行后錯誤，但不起作用）我對其進行了跟蹤，發現甚至位圖數組也不為空並且該類正常工作； 但是picturebox不顯示array（bitmap）的值。

班級

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace GRID
{
    class MasterSplitter
    {
        public BitmapArray_Block[] BMP2Array(Bitmap inp, Point BlockSize)
        {
        if (BlockSize.X > inp.Width || BlockSize.Y > inp.Height)
            BlockSize.X = BlockSize.Y = 100;

        int NW =0, NH = 0;
        int tx =1, ty = 1;
        if (((inp.Width%BlockSize.X) == 0) && ((inp.Height%BlockSize.Y) == 0))
        {
            NW = inp.Width;
            NH = inp.Height;
        }
        else
        {
            tx= inp.Width / BlockSize.X;
            NW = (BlockSize.X*tx) +BlockSize.X;
            ty = inp.Height / BlockSize.Y;
            NH = (BlockSize.Y * ty) + BlockSize.Y; 
        }

        //Operations for making an exact bitmap size
        Bitmap Temp = new Bitmap(NW, NH);
        Graphics g = Graphics.FromImage(Temp);
        g.DrawImage(inp, 0, 0, new Rectangle(0,0,Temp.Width, Temp.Height), GraphicsUnit.Pixel);
        g.Dispose(); //Cleaning up; Temp now has the exact bitmap size of what input BMP should has for devision.

        BitmapArray_Block[] T = new BitmapArray_Block[(tx * ty) + 1]; //Array for Bitmap MatriX

        int Xpos = 0, Ypos;
        int counter =0;
        for (int i=0; i<tx; i++)
        {
            Ypos = 0;
            for (int j=0;j<ty;j++)
            {
                BitmapArray_Block t = new BitmapArray_Block();
                t.start_location = new Point(Xpos,Ypos);
                t.BMP = new Bitmap(BlockSize.X,BlockSize.Y);
                Graphics gt = Graphics.FromImage(t.BMP);
                gt.DrawImage(Temp, Xpos, Ypos, new Rectangle(0, 0, t.BMP.Width, t.BMP.Height), GraphicsUnit.Pixel);
                gt.Dispose();
                T[counter] = t;

                Ypos += BlockSize.Y;
                counter+=1;
            }
            Xpos += BlockSize.X;
        }

        return T;
    }



    public class BitmapArray_Block
    {
        public Point start_location;

        public Bitmap BMP;


    }
}

顯示結果的代碼：

private void button1_Click(object sender, EventArgs e)
{
    MasterSplitter M = new MasterSplitter();
    BitmapArray_Block[] T =M.BMP2Array(new Bitmap(pictureBox1.Image),new Point(100,100));
    pictureBox1.Image = T[1].BMP;
}

Answer 1

您將DrawImage的參數弄錯了。 檢查參數說明。 開頭的x和y是繪制圖像的坐標，並且矩形（與某些其他重載不同）指定將要繪制的原始圖像部分。

這意味着您當前的代碼始終使用源圖像的左上角，並且在處理了（0,0）的第一個塊之后，您嘗試繪制的部分將簡單地繪制在可用框架的外部。 如果您已經在T[0].BMP上進行過測試，則它實際上可以工作，但是從索引1開始，所有圖像將為空。

正確的代碼應為：

// "using" will automatically dispose the resource after use, even in case of exceptions.
using(Graphics gt = Graphics.FromImage(t.BMP))
    gt.DrawImage(Temp, 0, 0, new Rectangle(Xpos, Ypos, BlockSize.X, BlockSize.Y), GraphicsUnit.Pixel);