答えは実際には非常に簡単です。
フォントスタイルをForm1[Arial; 8,25pt]。デザイナーを見てみましょう:
private void InitializeComponent()
{
System.Windows.Forms.DataGridViewCellStyle dataGridViewCellStyle1 = new System.Windows.Forms.DataGridViewCellStyle();
this.dataGridView1 = new System.Windows.Forms.DataGridView();
this.Column1 = new System.Windows.Forms.DataGridViewTextBoxColumn();
this.Column2 = new System.Windows.Forms.DataGridViewTextBoxColumn();
this.Column3 = new System.Windows.Forms.DataGridViewTextBoxColumn();
((System.ComponentModel.ISupportInitialize)(this.dataGridView1)).BeginInit();
this.SuspendLayout();
//
// dataGridView1
//
dataGridViewCellStyle1.Alignment = System.Windows.Forms.DataGridViewContentAlignment.MiddleLeft;
dataGridViewCellStyle1.BackColor = System.Drawing.SystemColors.Control;
dataGridViewCellStyle1.Font = new System.Drawing.Font("Calibri", 9.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((byte)(238)));
dataGridViewCellStyle1.ForeColor = System.Drawing.SystemColors.WindowText;
dataGridViewCellStyle1.SelectionBackColor = System.Drawing.SystemColors.Highlight;
dataGridViewCellStyle1.SelectionForeColor = System.Drawing.SystemColors.HighlightText;
dataGridViewCellStyle1.WrapMode = System.Windows.Forms.DataGridViewTriState.True;
this.dataGridView1.ColumnHeadersDefaultCellStyle = dataGridViewCellStyle1;
this.dataGridView1.ColumnHeadersHeightSizeMode = System.Windows.Forms.DataGridViewColumnHeadersHeightSizeMode.AutoSize;
this.dataGridView1.Columns.AddRange(new System.Windows.Forms.DataGridViewColumn[] {
this.Column1,
this.Column2,
this.Column3});
this.dataGridView1.EnableHeadersVisualStyles = false;
this.dataGridView1.Location = new System.Drawing.Point(49, 62);
this.dataGridView1.Name = "dataGridView1";
this.dataGridView1.Size = new System.Drawing.Size(443, 309);
this.dataGridView1.TabIndex = 0;
//
// Column1
//
this.Column1.HeaderText = "Column1";
this.Column1.Name = "Column1";
//
// Column2
//
this.Column2.HeaderText = "Column2";
this.Column2.Name = "Column2";
//
// Column3
//
this.Column3.HeaderText = "Column3";
this.Column3.Name = "Column3";
//
// Form1
//
this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 14F);
this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
this.ClientSize = new System.Drawing.Size(546, 457);
this.Controls.Add(this.dataGridView1);
this.Font = new System.Drawing.Font("Arial", 8.25F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(238)));
this.Name = "Form1";
this.Text = "Form1";
this.Load += new System.EventHandler(this.Form1_Load);
((System.ComponentModel.ISupportInitialize)(this.dataGridView1)).EndInit();
this.ResumeLayout(false);
}
ご覧のとおり、Datagridviewヘッダーのフォント設定は保存されています。それでも、フォームのフォント設定はその後表示され、最終的にはDatagridviewのフォント設定が上書きされます。
私のアドバイスは、フォームのフォント設定をデフォルトに戻すことです。