正在重写DataGridViewTextBoxCell绘制方法

本文关键字：绘制 方法 DataGridViewTextBoxCell 重写 | 更新日期: 2023-09-27 17:47:46

我正试图在派生类中重写DataGridViewTextBoxCell的绘制方法，以便可以将前景文本缩进一些可变的像素量。如果列的宽度进行调整，使其总宽度为单元格文本的长度加上"缓冲区"缩进，我会喜欢它。有人知道实现这一点的方法吗？我的lame实现如下所示：

public class MyTextBoxCell : DataGridViewTextBoxCell{ ....
        protected override void Paint(Graphics graphics, Rectangle clipBounds, Rectangle cellBounds, int rowIndex, DataGridViewElementStates cellState, object value, object formattedValue, string errorText, DataGridViewCellStyle cellStyle, DataGridViewAdvancedBorderStyle advancedBorderStyle, DataGridViewPaintParts paintParts) {
           clipBounds.Inflate(100, 0);
            DataGridViewPaintParts pp = DataGridViewPaintParts.Background | DataGridViewPaintParts.Border | DataGridViewPaintParts.ContentBackground
                | DataGridViewPaintParts.ErrorIcon;
            base.Paint(graphics, clipBounds, cellBounds, rowIndex, cellState, value, formattedValue, errorText, cellStyle, advancedBorderStyle, pp);            
                string text = formattedValue as string;
//My lame attempt to indent 20 pixels??
                TextRenderer.DrawText(graphics, text, cellStyle.Font, new Point(cellBounds.Location.X + 20, cellBounds.Location.Y), cellStyle.SelectionForeColor ,TextFormatFlags.EndEllipsis);
}

}

正在重写DataGridViewTextBoxCell绘制方法

您只需连接到datagridview中的CellFormattingEvent并在那里进行格式化。或者，如果您是从DataGridView继承的，您可以直接重写OnCellFormatting方法。代码看起来像这样：

            if (e.ColumnIndex == 1)
            {
                string val = (string)e.Value;
                e.Value = String.Format("   {0}", val);
                e.FormattingApplied = true;
            }

只是一些粗略的代码，但你已经明白了。

我想我有了。如果有人感兴趣，下面的代码是：

public class MyTextBoxCell : DataGridViewTextBoxCell{ ....
        private static readonly int INDENTCOEFFICIENT = 5;
        protected override Size GetPreferredSize(Graphics graphics, DataGridViewCellStyle cellStyle, int rowIndex, Size constraintSize) {
            int indent = ((MyRow)OwningRow).Indent * INDENTCOEFFICIENT;
            Size s =  base.GetPreferredSize(graphics, cellStyle, rowIndex, constraintSize);
            int textWidth = 2;  //arbitrary amount
            if (Value != null) {
                string text = Value as string;
                textWidth = TextRenderer.MeasureText(text, cellStyle.Font).Width;
            }
            s.Width += textWidth + indent;
            return s;
        }
        private static readonly StringFormat strFmt = new StringFormat(StringFormatFlags.NoWrap);
        protected override void Paint(Graphics graphics, Rectangle clipBounds, Rectangle cellBounds, int rowIndex, DataGridViewElementStates cellState, object value, object formattedValue, string errorText, DataGridViewCellStyle cellStyle, DataGridViewAdvancedBorderStyle advancedBorderStyle, DataGridViewPaintParts paintParts) {
            DataGridViewPaintParts pp = DataGridViewPaintParts.Background | DataGridViewPaintParts.Border | DataGridViewPaintParts.ContentBackground
                | DataGridViewPaintParts.ErrorIcon;
            base.Paint(graphics, clipBounds, cellBounds, rowIndex, cellState, value, formattedValue, errorText, cellStyle, advancedBorderStyle, pp);
            string text = formattedValue as string;
            int indent = ((MyRow)OwningRow).Indent * INDENTCOEFFICIENT;
            strFmt.Trimming = StringTrimming.EllipsisCharacter;
            Rectangle r = cellBounds;
            r.Offset(indent, 0);
            r.Inflate(-indent, 0);
            graphics.DrawString(text, cellStyle.Font, Brushes.Black, r, strFmt);
        }
}

如果有人有更好的方法，我希望看到你的解决方案。

如果您试图自动调整列的大小（取决于单元格内容的大小），那么您应该查看Column.AutoSizeMode属性和Column.DefaultCellStyle属性。

static const int INDENTCOEFF = 5;
DataGridViewCellStyle cellStyle = new DataGridViewCellStyle();
cellStyle.Padding = 
         new Padding(INDENTCOEFF , 5, INDENTCOEFF , 5); //left,top,right,bottom
MyColumn.DefaultCellStyle = cellStyle;
MyColumn.AutoSizeMode = DataGridViewAutoSizeColumnMode.AllCells;
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