随笔- 206 文章- 1 评论- 48 阅读- 33万

C#--自定义控件-panel控件（渐变色，文字的绘制）

以下是学习笔记：

参考：https://www.bilibili.com/video/BV1eQ4y1M7ZY?p=3

自定义控件开发的思路：属性，事件，Paint(重写），这三个不一定都要有的

效果：

用途：分类显示内容的场景

一，自定义控件

1，添加“组件类”

,2，根据自定义控件的功能修改继承

3，代码如下：

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

namespace Jason_Controls
{
    public partial class JasonPanel : Panel
    {
        public JasonPanel()
        {
            InitializeComponent();
        }
 
        public JasonPanel(IContainer container)
        {
            container.Add(this);
 
            InitializeComponent();
        }
 
        #region 属性
 
        private Color headBackColor=Color.LimeGreen;
        [Category("Jason控件自定义属性")]
        [Description("标题的背景颜色")]
        public Color HeadBackColor
        {
            get { return headBackColor; }
            set
            {
                headBackColor = value; 
                this.Invalidate();
            }
        }
 
        private Color headForeColor = Color.Black;
        [Category("Jason控件自定义属性")]
        [Description("标题的前景颜色")]
        public Color HeadForeColor
        {
            get { return headForeColor; }
            set
            {
                headForeColor = value;
                this.Invalidate();
            }
        }
 
        private int headHeight = 30;
        [Category("Jason控件自定义属性")]
        [Description("标题的高度")]
        public int HeadHeight
        {
            get { return headHeight; }
            set
            {
                headHeight = value;
                this.Invalidate();
            }
        }
 
        private string headText = "标题名称";
        [Category("Jason控件自定义属性")]
        [Description("标题的内容")]
        public string HeadText
        {
            get { return headText; }
            set
            {
                headText = value;
                this.Invalidate();
            }
        }
 
        private float linearScale= 0.4f;
        [Category("Jason控件自定义属性")]
        [Description("渐变的程度")]
        public float LinearScale
        {
            get { return linearScale; }
            set
            {
                linearScale = value;
                this.Invalidate();
            }
        }
 
 
        #endregion
 
        #region 字段
        //画布
        private Graphics g;
        //画笔
        private Pen p;
        //画刷
        private SolidBrush sb;
        
        #endregion
 
        #region 绘制过程
 
        protected override void OnPaint(PaintEventArgs e)
        {
            base.OnPaint(e);
 
            //自定义绘制过程
 
            //获取画布
            g = e.Graphics;
 
            //设置画布
            SetGraphics(g);
 
            //绘制过程
 
            //【1】画标题框
 
            //LinearGradientBrush渐变色的画刷,有四个参数
            //参数1：new PointF(0, 0)左上角
            //参数2：new PointF(0, this.headHeight) 左下角
            //参数1和参数2说是从上往下渐变
            //参数3：渐变的第一个颜色
            //参数4：渐变的第二个颜色
            using (LinearGradientBrush brush = new LinearGradientBrush(new PointF(0, 0), new PointF(0, this.headHeight),
                setStartLinearColor(this.headBackColor), this.headBackColor))
            {
                //填充矩形
                g.FillRectangle(brush,new Rectangle(0,0,this.Width,this.headHeight));//参数1：画刷 参数2：矩形
            }
             
            //【2】绘制文字
            StringFormat sf=new StringFormat();//格式
            sf.Alignment = StringAlignment.Center;//水平居中
            sf.LineAlignment = StringAlignment.Center;//垂直居中
            using (SolidBrush sb=new SolidBrush(this.headForeColor))
            {
                g.DrawString(this.headText,this.Font,sb, new Rectangle(0, 0, this.Width, this.headHeight),sf);
            }
 
            //【3】绘制边框
            using (Pen p =new Pen(this.headForeColor))
            {
                //g.DrawRectangle(p, 0, 0, this.Width, this.Height);//只显示一半，原因：默认的笔有1个像素的宽度，画的矩形超过了控件的1个像素的，就画出去啦
                g.DrawRectangle(p, 0, 0, this.Width - 1, this.Height - 1);               
                g.DrawLine(p,0,this.headHeight,this.Width-1,this.headHeight);
            }
 
             
 
 
        }
 
        private Color setStartLinearColor(Color EndLinearColor)
        {
            return Color.FromArgb((int)(EndLinearColor.R + (255 - EndLinearColor.R) * this.linearScale),
                (int)(EndLinearColor.G + (255 - EndLinearColor.G) * this.linearScale),
                (int) (EndLinearColor.B + (255 - EndLinearColor.B) * this.linearScale));
        }
 
 
        #endregion
 
 
        #region 设置画布属性的方法
 
        private void SetGraphics(Graphics g)
        {
            //设置画布的属性
            g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;//消除锯齿
            g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;//高质量显示
 
            g.TextRenderingHint = System.Drawing.Text.TextRenderingHint.ClearTypeGridFit;//字体，是字体更加清晰
            g.TextRenderingHint = System.Drawing.Text.TextRenderingHint.AntiAlias;//字体消除锯齿
        }
 
        #endregion
    }
}

二，绘制过程讲解

1，绘制过程

1，渐变方向的说明：

3，渐变颜色的通用算法

private Color setStartLinearColor(Color EndLinearColor)
{
    return Color.FromArgb((int)(EndLinearColor.R + (255 - EndLinearColor.R) * this.linearScale),
        (int)(EndLinearColor.G + (255 - EndLinearColor.G) * this.linearScale),
        (int) (EndLinearColor.B + (255 - EndLinearColor.B) * this.linearScale));
}