How to get the textheight of a textbox?

[limengchen]

I want to set the height property of a textbox to just the same as its textheight so that there won't be scrollbars. How to do that?

[gpontop]

You should set the Multiline property to "false" so as to make it's height fit into the size of it's texts.

[feigehao]

textBox1.Bounds.Height

[FileNewExit]

TextBox.Font.Height

[gpontop]

This is my example ,try it please!
----------------------------------------------------------------------------------
using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;

namespace WindowsApplication2
{
/// <summary>
/// Form1 的摘要说明。
/// </summary>
public class Form1 : System.Windows.Forms.Form
{
private System.Windows.Forms.TextBox textBox1;
private System.Windows.Forms.ComboBox comboBox1;
private System.Windows.Forms.FontDialog fontDialog1;
private System.Windows.Forms.Button button1;
/// <summary>
/// 必需的设计器变量。
/// </summary>
private System.ComponentModel.Container components = null;

public Form1()
{
//
// Windows 窗体设计器支持所必需的
//
InitializeComponent();

//
// TODO: 在 InitializeComponent 调用后添加任何构造函数代码
//
}

/// <summary>
/// 清理所有正在使用的资源。
/// </summary>
protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Dispose();
}
}
base.Dispose( disposing );
}

#region Windows 窗体设计器生成的代码
/// <summary>
/// 设计器支持所需的方法 - 不要使用代码编辑器修改
/// 此方法的内容。
/// </summary>
private void InitializeComponent()
{
this.textBox1 = new System.Windows.Forms.TextBox();
this.comboBox1 = new System.Windows.Forms.ComboBox();
this.fontDialog1 = new System.Windows.Forms.FontDialog();
this.button1 = new System.Windows.Forms.Button();
this.SuspendLayout();
//
// textBox1
//
this.textBox1.AcceptsReturn = true;
this.textBox1.BorderStyle = System.Windows.Forms.BorderStyle.None;
this.textBox1.Font = new System.Drawing.Font("宋体", 9F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((System.Byte)(134)));
this.textBox1.Location = new System.Drawing.Point(8, 48);
this.textBox1.Multiline = true;
this.textBox1.Name = "textBox1";
this.textBox1.Size = new System.Drawing.Size(272, 272);
this.textBox1.TabIndex = 0;
this.textBox1.Text = "textBox1";
this.textBox1.BorderStyleChanged += new System.EventHandler(this.textBox1_BorderStyleChanged);
this.textBox1.FontChanged += new System.EventHandler(this.textBox1_FontChanged);
this.textBox1.TextChanged += new System.EventHandler(this.textBox1_TextChanged);
//
// comboBox1
//
this.comboBox1.Items.AddRange(new object[] {
"None",
"FixedSingle",
"Fixed3D"});
this.comboBox1.Location = new System.Drawing.Point(8, 16);
this.comboBox1.Name = "comboBox1";
this.comboBox1.Size = new System.Drawing.Size(121, 20);
this.comboBox1.TabIndex = 2;
this.comboBox1.Text = "BorderStyle";
this.comboBox1.SelectedIndexChanged += new System.EventHandler(this.comboBox1_SelectedIndexChanged);
//
// button1
//
this.button1.Location = new System.Drawing.Point(208, 16);
this.button1.Name = "button1";
this.button1.TabIndex = 3;
this.button1.Text = "font";
this.button1.Click += new System.EventHandler(this.button1_Click);
//
// Form1
//
this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);
this.ClientSize = new System.Drawing.Size(288, 325);
this.Controls.Add(this.button1);
this.Controls.Add(this.comboBox1);
this.Controls.Add(this.textBox1);
this.Name = "Form1";
this.Text = "Form1";
this.ResumeLayout(false);

}
#endregion

/// <summary>
/// 应用程序的主入口点。
/// </summary>
[STAThread]
static void Main()
{
Application.Run(new Form1());
}

private void ChangeBounds()
{
int intLineNum = this.textBox1.Lines.GetLength(0);//The line number of the textbox
float fFontHeight = this.textBox1.Font.GetHeight();//The height of the currently used font in pixel
int intBorderHeight = 0;//The height of the currently used border style
Font font = this.textBox1.Font;

int ifontEmSize = font.FontFamily.GetEmHeight(font.Style);//The EmHeight of the font
int ifontDescent = font.FontFamily.GetCellDescent(font.Style);//Descent height of the font
int ifontAscent = font.FontFamily.GetCellAscent(font.Style);//Ascent height of the font
int ilineSpace = font.FontFamily.GetLineSpacing(font.Style);//Line distence of the font
double dCurRate = fFontHeight / (double) ilineSpace;//The ratio of pixel/DesignUnits
int iLineSpaceHeight = ilineSpace - ifontDescent - ifontAscent;//The height of external leading



switch(this.textBox1.BorderStyle)
// Set the Curently used border height
{
case System.Windows.Forms.BorderStyle.None:
intBorderHeight = 0;
break;
case System.Windows.Forms.BorderStyle.FixedSingle:
intBorderHeight = System.Windows.Forms.SystemInformation.BorderSize.Height;
break;
case System.Windows.Forms.BorderStyle.Fixed3D:
intBorderHeight = System.Windows.Forms.SystemInformation.Border3DSize.Height;
break;
}

if (intLineNum == 0)
//To make the minimised height to the height of one line
{
intLineNum = 1;
}

//Please refer to the following msdn topic
//----http://msdn.microsoft.com/library/en-us/cpguide/html/_gdiplus_obtaining_font_metrics_usecsharp.asp
double d = (double) (intLineNum * ifontEmSize + iLineSpaceHeight) * dCurRate;

int t = (int) ( d + 0.5 ) + 2 * intBorderHeight;
this.textBox1.Height = t;

}

private void textBox1_BorderStyleChanged(object sender, System.EventArgs e)
{
this.ChangeBounds();
}

private void comboBox1_SelectedIndexChanged(object sender, System.EventArgs e)
{
switch(this.comboBox1.SelectedItem.ToString())
{
case "None":
this.textBox1.BorderStyle = System.Windows.Forms.BorderStyle.None;
break;
case "FixedSingle":
this.textBox1.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle;
break;
case "Fixed3D":
this.textBox1.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D;
break;
}
this.textBox1.Update();
}

private void button1_Click(object sender, System.EventArgs e)
{
this.fontDialog1.ShowDialog(this.textBox1);
this.textBox1.Font = this.fontDialog1.Font;
}

private void textBox1_FontChanged(object sender, System.EventArgs e)
{
this.ChangeBounds();
}

private void textBox1_TextChanged(object sender, System.EventArgs e)
{
this.ChangeBounds();
}
}
}

[limengchen]

to gpontop():
你那段代码不能处理自动换行。

[drag2003]

You should set the Multiline property to "false" so as to make it's height fit into the size of it's texts.

就应该把"Multiline" 属性设成"false"，这样就能使它的高度适应文本的大小。

[gpontop]

我只处理了高度，没处理宽度，其实处理方式是一样的。

[gpontop]

两边加起来同时控制还有些难度，假如把“WordWrap”设置为true，就可以单行字符自动换行，然而控制行数就有些麻烦了，还没搞定，再看看

[limengchen]

to drag2003:
How can I show multiline strings if I set the multiline property to false?

[ssdjmcj8048]

用Control.CreateGraphics().MeasureString