C#Graphics图片上添加文字并按点旋转

布满荆棘的人生 2022-05-19 02:44 200阅读 0赞

**Graphics图片上添加文字并按点旋转**

1.  设置文本布局信息StringFormat 类，其中属性StringFormat.Alignments设置文字水平对齐，StringFormat.LineAlignment设置垂直对其，StringAlignment中属性Center（字符串中心与位置中心对齐）、Far（字符串远端即文字结尾与位置中心对齐）、Near（字符串近端即文字开头与与位置中心对齐）
2.  设置画布旋转 Graphics.Transform，旋转矩阵，Matrix.RotateAt (角度，旋转中心点位置，旋转顺序默认顺时针)
3.  写字Graphics.DrawString（字符串，字体，笔刷，位置，对齐）

using System;
    using System.Collections.Generic;
    using System.ComponentModel;
    using System.Data;
    using System.Drawing;
    using System.Drawing.Drawing2D;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;
    using System.Windows.Forms;
    
    namespace A003
    {
        public partial class Form1 : Form
        {
            public Form1()
            {
                InitializeComponent();
                img = Image.FromFile("C:\\Users\\ibit\\Downloads\\a.jpg");
            }
            Graphics g;
            Image img;
    
            private void button1_Click(object sender, EventArgs e)
            {
                Graphics gBmp = Graphics.FromImage(img);
    
                //添加文字
                String str1 = "1ABCDE";
                String str2 = "2ABCDEABCDE";
                String str3 = "3ABCDEABCDEABCDE";
                Font font = new Font("微软雅黑", 16);
                SolidBrush sbrush1 = new SolidBrush(Color.Black);
                SolidBrush sbrush2 = new SolidBrush(Color.Red);
    
                //笔刷渐变效果
                //LinearGradientBrush sbrush3 = new LinearGradientBrush(new PointF(100, 100), new PointF(250,250), Color.Red ,Color.Black); 
                SolidBrush sbrush3 = new SolidBrush(Color.Blue);
    
                //绘制饼图
                //SolidBrush s1 = new SolidBrush(Color.Pink);
                //gBmp.FillPie(s1, 150, 150, 200, 150, 90, 200);
                //SolidBrush s2 = new SolidBrush(Color.Purple);
                //gBmp.FillPie(s2, 150, 150, 200, 150, 290, 70);
                //SolidBrush s3 = new SolidBrush(Color.Green);
                //gBmp.FillPie(s3, 150, 150, 200, 150, 0, 60);
                //SolidBrush s4 = new SolidBrush(Color.Brown);
                //gBmp.FillPie(s4, 150, 150, 200, 150, 60, 30);
    
                //文字位置中心点坐标
                Pen p1 = new Pen(Color.Green,3);
                gBmp.DrawLine(p1,0,100,200,100);
                gBmp.DrawLine(p1, 100, 0, 100, 200);
               // Rectangle rect = new Rectangle(200,200,100,70);
               // gBmp.DrawEllipse(p1,rect);
    
    
                StringFormat format1 = new StringFormat();
                //指定字符串的水平对齐方式
                format1.Alignment = StringAlignment.Far;
                //表示字符串的垂直对齐方式
                format1.LineAlignment = StringAlignment.Center;
                StringFormat format2 = new StringFormat();
                //指定字符串的水平对齐方式
                format2.Alignment = StringAlignment.Center;
                //表示字符串的垂直对齐方式
                format2.LineAlignment = StringAlignment.Center;
                StringFormat format3 = new StringFormat();
                //指定字符串的水平对齐方式
                format3.Alignment = StringAlignment.Near;
                //表示字符串的垂直对齐方式
                format3.LineAlignment = StringAlignment.Center;
    
                //旋转角度和平移
                Matrix mtxRotate = gBmp.Transform;
                mtxRotate.RotateAt(30, new PointF(100, 100));
                gBmp.Transform = mtxRotate;
    
                gBmp.DrawString(str1, font, sbrush1, new PointF(100, 100), format1);
                gBmp.DrawString(str2, font, sbrush2, new PointF(100, 100), format2);
               gBmp.DrawString(str3, font, sbrush3, new PointF(100, 100), format3);
    
    
                g = this.CreateGraphics();
                g.DrawImage(img, 0, 0);
    
                gBmp.Dispose();
            }
        }
    
    
    }