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<p class="MsoNormal"><span style="FONT-FAMILY: 宋体">图</span><span lang="EN-US">22-16</span><span style="FONT-FAMILY: 宋体">显示了把一个</span><span lang="EN-US">Binding</span><span style="FONT-FAMILY: 宋体">添加到控件中的情况。绑定把控件链接到数据源上，存储在</span><span lang="EN-US">Form(</span><span style="FONT-FAMILY: 宋体">或控件本身</span><span lang="EN-US">)</span><span style="FONT-FAMILY: 宋体">的</span><span lang="EN-US">BindingContext</span><span style="FONT-FAMILY: 宋体">中。数据源内部的改变会反映到控件上，控件中的改变也会反映到数据源上。</span></p>
<h4 style="FTEL: 21.45pt"><span lang="EN-US">2. Binding</span><span style="FONT-FAMILY: 黑体">类</span></h4>
<p class="MsoNormal"><span style="FONT-FAMILY: 宋体">这个类把控件的一个属性链接到数据源的一个成员上。在改变该成员时，控件的属性会更新，以反映这个改变。反之亦然，如果文本框中的文本被更新，这个改变也会反映到数据源上。</span></p>
<p align="center"><span lang="EN-US"><img height="366" src="22/image016.gif" width="273" alt="" /></span></p>
<p style="FTEL: 8.15pt" align="center"><span style="FONT-FAMILY: 宋体">图</span><span lang="EN-US"> 22-16</span></p>
<p class="MsoNormal"><a ftel="Binding"><span style="FONT-FAMILY: 宋体">可以把任何列绑定到控件的任何属性上，例如，可以把列绑定到一个文本框中，也可以把另一个列绑定到文本框的颜色上。可以把控件的属性绑定到完全不同的数据源上，例如，单元格的颜色可以在一个颜色表中定义，而实际的数据可以在另一个表中定义。</span></a></p>
<h4 style="FTEL: 21.45pt"><span lang="EN-US">3. CurrencyManager</span><span style="FONT-FAMILY: 黑体">和</span><span lang="EN-US">PropertyManager </span></h4>
<p class="MsoNormal"><span style="FONT-FAMILY: 宋体">在创建</span><span lang="EN-US">Binding</span><span style="FONT-FAMILY: 宋体">对象时，如果这是第一次绑定数据源中的数据，就会创建对应的</span><span lang="EN-US">CurrencyManager </span><span style="FONT-FAMILY: 宋体">或</span> <span lang="EN-US">PropertyManager</span><span style="FONT-FAMILY: 宋体">对象。这个类的作用是定义当前记录在数据源中的位置，在改变当前的记录时，需要调整所有的</span><span lang="EN-US">ListBindings</span><span style="FONT-FAMILY: 宋体">。图</span><span lang="EN-US">22-17</span><span style="FONT-FAMILY: 宋体">显示了</span><span lang="EN-US">Products</span><span style="FONT-FAMILY: 宋体">表中的两个字段，包含一种通过跟踪栏控件在记录之间移动的方式。</span></p>
<p align="center"><span lang="EN-US"><img height="105" src="22/image017.jpg" width="319" alt="" /></span></p>
<p style="FTEL: 8.15pt" align="center"><span style="FONT-FAMILY: 宋体">图</span><span lang="EN-US"> 22-17</span></p>
<p class="MsoNormal"><span lang="EN-US">ScrollingDataBinding</span><span style="FONT-FAMILY: 宋体">示例的代码如下所示：</span></p>
<p class="2" style="MARGIN-TOP: 8.15pt; MARGIN-LEFT: 21.45pt; MARGIN-RIGHT: 0cm; FTEL: 18.45pt"><span lang="EN-US">using System;</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US">using System.Windows.Forms;</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US">using System.Data;</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US">using System.Data.SqlClient;</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> </span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US">public class ScrollingDataBinding : System.Windows.Forms.Form</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US">{</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> private Button retrieveButton;</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> private TextBox textName;</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> private TextBox textQuan;</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> private TrackBar trackBar;</span></p>
<p class="2" style="MARGIN-TOP: 0cm; MARGIN-LEFT: 21.45pt; MARGIN-RIGHT: 0cm; FTEL: 18.45pt"><span lang="EN-US"> private DataSet ds;</span></p>
<p class="MsoNormal"><span style="FONT-FAMILY: 宋体">应用程序在</span><span lang="EN-US">ScrollingDataBinding</span><span style="FONT-FAMILY: 宋体">构造函数中创建窗口以及该窗口中的所有控件：</span></p>
<p class="2" style="MARGIN-TOP: 8.15pt; MARGIN-LEFT: 21.45pt; MARGIN-RIGHT: 0cm; FTEL: 18.45pt"><span lang="EN-US"> public ScrollingDataBinding()</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> {</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> this.ClientSize = new System.Drawing.Size(464, 253);</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> this.Text = "09_ScrollingDataBinding";</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> this.retrieveButton = new Button();</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> retrieveButton.Location = new System.Drawing.Point(4, 4);</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> retrieveButton.Size = new System.Drawing.Size(75, 23);</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> retrieveButton.TabIndex = 1;</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> retrieveButton.Anchor = AnchorStyles.Top | AnchorStyles.Left;</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> retrieveButton.Text = "Retrieve";</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> retrieveButton.Click += new System.EventHandler</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> (this.retrieveButton_Click);</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> this.Controls.Add(this.retrieveButton);</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> this.textName = new TextBox();</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> textName.Location = new System.Drawing.Point(4, 31);</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> textName.Text = "Please click retrieve...";</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> textName.TabIndex = 2;</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> textName.Anchor = AnchorStyles.Top | AnchorStyles.Left | </span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> AnchorStyles.Right ;</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> textName.Size = new System.Drawing.Size(456, 20);</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> textName.Enabled = false;</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> this.Controls.Add(this.textName);</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> this.textQuan = new TextBox();</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> textQuan.Location = new System.Drawing.Point(4, 55);</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> textQuan.Text = "";</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> textQuan.TabIndex = 3;</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> textQuan.Anchor = AnchorStyles.Top | AnchorStyles.Left | </span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> AnchorStyles.Top;</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> textQuan.Size = new System.Drawing.Size(456, 20);</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> textQuan.Enabled = false;</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> this.Controls.Add(this.textQuan);</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> this.trackBar = new TrackBar();</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> trackBar.BeginInit();</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> trackBar.Dock = DockStyle.Bottom ;</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> trackBar.Location = new System.Drawing.Point(0, 275);</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> trackBar.TabIndex = 4;</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> trackBar.Size = new System.Drawing.Size(504, 42);</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> trackBar.Scroll += new System.EventHandler(this.trackBar_Scroll);</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> trackBar.Enabled = false;</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> this.Controls.Add(this.trackBar);</span></p>
<p class="2" style="MARGIN-TOP: 0cm; MARGIN-LEFT: 21.45pt; MARGIN-RIGHT: 0cm; FTEL: 18.45pt"><span lang="EN-US"> }</span></p>
<p class="MsoNormal"><span style="FONT-FAMILY: 宋体">单击</span><span lang="EN-US">Retrieve</span><span style="FONT-FAMILY: 宋体">按钮后，事件处理程序就会从</span><span lang="EN-US">Products</span><span style="FONT-FAMILY: 宋体">表中选择所有的记录，并把它们保存到私有数据集</span><span lang="EN-US">ds</span><span style="FONT-FAMILY: 宋体">中：</span></p>
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