C#中DataBindings用法实例分析

using system;
using system.collections.generic;
using system.componentmodel;
using system.data;
using system.drawing;
using system.linq;
using system.text;
using system.windows.forms;
namespace databindingstest
{
  public partial class form2 : form
  {
    public form2()
    {
      initializecomponent();
    }
    mydatasource mydatasource = new mydatasource(); //应用于第二种方式
    public int num { get; set; } //应用于第三种方式
    public list<blognew> blognews { get; set; } //应用于第四种方式
    public bindinglist<blognew> blognewsregardui { get; set; } //应用于datagridview界面ui更新 
    private void mainfrm_load(object sender, eventargs e)
    {
      #region 测试一
      /************************************************
       * 第一个值：要绑定到textbox的什么地方
       * 第二个值：数据源是什么
       * 第三个值：应该取数据源的什么属性
       * 第四个值：是否开启数据格式化
       * 第五个值：在什么时候启用数据源绑定
       * *********************************************/
      textbox1.databindings.add("text", trackbar1, "value", false, datasourceupdatemode.onpropertychanged);
      #endregion
      #region 测试二
      /*********************************************
       * 这个主要就是通过一个外部的类，当做数据源
       * *********************************************/
      mydatasource.myvalue = "这是个测试";
      textbox2.databindings.add("text", mydatasource, "myvalue", false, datasourceupdatemode.onpropertychanged);
      #endregion
      #region 测试三
      /*****************************************
       *这个主要就是通过本身拥有的属性，当做数据源
       ****************************************/
      num = 5;
      textbox3.databindings.add("text", this, "num", false, datasourceupdatemode.onpropertychanged);
      #endregion
      /*
       * 注意：上面的3个测试，改变文本框中的值，数据源中对应的属性值会改变  
       *    但是，数据源的属性值改变了，文本框中的值不会改变
       */
      #region 测试四 ： list<t>
      blognews = new list<blognew>();
      blognews.add(new blognew { blogid = 1, blogtitle = "人生若只如初见" });
      blognews.add(new blognew { blogid = 2, blogtitle = "何事秋风悲画扇" });
      blognews.add(new blognew { blogid = 3, blogtitle = "最喜欢纳兰性德" });
      datagridview1.databindings.add("datasource", this, "blognews", false, datasourceupdatemode.onpropertychanged);
      #endregion
      #region 测试五 ： bindinglist<t>
      blognewsregardui = new bindinglist<blognew>();
      blognewsregardui.add(new blognew { blogid = 11, blogtitle = "僵卧孤村不自哀" });
      blognewsregardui.add(new blognew { blogid = 12, blogtitle = "尚思为国戍轮台" });
      blognewsregardui.add(new blognew { blogid = 13, blogtitle = "夜阑卧听风吹雨" });
      datagridview2.databindings.add("datasource", this, "blognewsregardui", false, datasourceupdatemode.onpropertychanged);
      #endregion
    }
    private void button1_click(object sender, eventargs e)
    {
      //从这里可以看出，改变了textbox2中的值，这里的值也改变了，原因是因为类属于引用类型
      messagebox.show(mydatasource.myvalue);
    }
    private void button2_click(object sender, eventargs e)
    {
      //从这里可以看出，改变了textbox3中的值，这里的值也改变了，
      //原因是num被当做了当前窗体的一个属性(窗体本身就是一个类)，也属于引用类型
      messagebox.show(num.tostring());
      //this.num = 10;
      //messagebox.show(num.tostring());
    }
    private void button3_click(object sender, eventargs e)
    {
      //在这里向datagridview中插入一行
      var data = datagridview1.datasource as list<blognew>;
      data.add(new blognew { blogid = 4, blogtitle = "取次花丛懒回顾，半缘修道半缘君" });
      foreach (blognew blognew in datagridview1.datasource as list<blognew>)
      {
        /***********
         * 当我们心插入一条blogid记录为4的数据的时候，在界面上可以看出datagridview1的datasource已经被更新，
         * 但是界面上依旧显示为blogid为1,2,3三条数据，很奇怪
         * *********************/
        messagebox.show(blognew.blogid + "--" + blognew.blogtitle);
      }
    }
    private void button4_click(object sender, eventargs e)
    {
      /*这里主要用来解决datagridview1界面不更新的问题，其实原因在于使用了list<blognew>,这里我们采用bindlist<blognew>
       *通过测试，我们发现，只要数据源改变，界面就可以自动的进行更新了，很是方便，不需要重新绑定
       */
      var dataregardui = datagridview2.datasource as bindinglist<blognew>;
      dataregardui.add(new blognew { blogid = 20, blogtitle = "竹外桃花三两枝，春江水暖鸭先知" });
    }
  }
  public class mydatasource
  {
    public string myvalue { get; set; }
  }
  public class blognew
  {
    public int blogid { get; set; }
    public string blogtitle { get; set; }
  }
}

namespace databindingstest
{
  partial class form2
  {
    /// <summary>
    /// required designer variable.
    /// </summary>
    private system.componentmodel.icontainer components = null;
    /// <summary>
    /// clean up any resources being used.
    /// </summary>
    /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
    protected override void dispose(bool disposing)
    {
      if (disposing && (components != null))
      {
        components.dispose();
      }
      base.dispose(disposing);
    }
    #region windows form designer generated code
    /// <summary>
    /// required method for designer support - do not modify
    /// the contents of this method with the code editor.
    /// </summary>
    private void initializecomponent()
    {
      this.groupbox1 = new system.windows.forms.groupbox();
      this.groupbox2 = new system.windows.forms.groupbox();
      this.button1 = new system.windows.forms.button();
      this.textbox2 = new system.windows.forms.textbox();
      this.groupbox3 = new system.windows.forms.groupbox();
      this.button2 = new system.windows.forms.button();
      this.textbox3 = new system.windows.forms.textbox();
      this.groupbox4 = new system.windows.forms.groupbox();
      this.button3 = new system.windows.forms.button();
      this.datagridview1 = new system.windows.forms.datagridview();
      this.groupbox5 = new system.windows.forms.groupbox();
      this.button4 = new system.windows.forms.button();
      this.datagridview2 = new system.windows.forms.datagridview();
      this.textbox1 = new system.windows.forms.textbox();
      this.trackbar1 = new system.windows.forms.trackbar();
      this.groupbox1.suspendlayout();
      this.groupbox2.suspendlayout();
      this.groupbox3.suspendlayout();
      this.groupbox4.suspendlayout();
      ((system.componentmodel.isupportinitialize)(this.datagridview1)).begininit();
      this.groupbox5.suspendlayout();
      ((system.componentmodel.isupportinitialize)(this.datagridview2)).begininit();
      ((system.componentmodel.isupportinitialize)(this.trackbar1)).begininit();
      this.suspendlayout();
      // 
      // groupbox1
      // 
      this.groupbox1.controls.add(this.trackbar1);
      this.groupbox1.controls.add(this.textbox1);
      this.groupbox1.location = new system.drawing.point(12, 12);
      this.groupbox1.name = "groupbox1";
      this.groupbox1.size = new system.drawing.size(200, 100);
      this.groupbox1.tabindex = 0;
      this.groupbox1.tabstop = false;
      this.groupbox1.text = "方式一";
      // 
      // groupbox2
      // 
      this.groupbox2.controls.add(this.button1);
      this.groupbox2.controls.add(this.textbox2);
      this.groupbox2.location = new system.drawing.point(218, 12);
      this.groupbox2.name = "groupbox2";
      this.groupbox2.size = new system.drawing.size(200, 100);
      this.groupbox2.tabindex = 2;
      this.groupbox2.tabstop = false;
      this.groupbox2.text = "方式二";
      // 
      // button1
      // 
      this.button1.location = new system.drawing.point(22, 59);
      this.button1.name = "button1";
      this.button1.size = new system.drawing.size(157, 23);
      this.button1.tabindex = 3;
      this.button1.text = "查看已修改的数据源的值";
      this.button1.usevisualstylebackcolor = true;
      this.button1.click += new system.eventhandler(this.button1_click);
      // 
      // textbox2
      // 
      this.textbox2.location = new system.drawing.point(22, 20);
      this.textbox2.name = "textbox2";
      this.textbox2.size = new system.drawing.size(157, 21);
      this.textbox2.tabindex = 2;
      // 
      // groupbox3
      // 
      this.groupbox3.controls.add(this.button2);
      this.groupbox3.controls.add(this.textbox3);
      this.groupbox3.location = new system.drawing.point(428, 12);
      this.groupbox3.name = "groupbox3";
      this.groupbox3.size = new system.drawing.size(200, 100);
      this.groupbox3.tabindex = 4;
      this.groupbox3.tabstop = false;
      this.groupbox3.text = "方式三";
      // 
      // button2
      // 
      this.button2.location = new system.drawing.point(22, 59);
      this.button2.name = "button2";
      this.button2.size = new system.drawing.size(157, 23);
      this.button2.tabindex = 3;
      this.button2.text = "查看已修改的数据源的值";
      this.button2.usevisualstylebackcolor = true;
      this.button2.click += new system.eventhandler(this.button2_click);
      // 
      // textbox3
      // 
      this.textbox3.location = new system.drawing.point(22, 20);
      this.textbox3.name = "textbox3";
      this.textbox3.size = new system.drawing.size(157, 21);
      this.textbox3.tabindex = 2;
      // 
      // groupbox4
      // 
      this.groupbox4.controls.add(this.button3);
      this.groupbox4.controls.add(this.datagridview1);
      this.groupbox4.location = new system.drawing.point(12, 118);
      this.groupbox4.name = "groupbox4";
      this.groupbox4.size = new system.drawing.size(568, 157);
      this.groupbox4.tabindex = 5;
      this.groupbox4.tabstop = false;
      this.groupbox4.text = "方式四";
      // 
      // button3
      // 
      this.button3.location = new system.drawing.point(377, 122);
      this.button3.name = "button3";
      this.button3.size = new system.drawing.size(157, 23);
      this.button3.tabindex = 4;
      this.button3.text = "插入一行";
      this.button3.usevisualstylebackcolor = true;
      this.button3.click += new system.eventhandler(this.button3_click);
      // 
      // datagridview1
      // 
      this.datagridview1.columnheadersheightsizemode = system.windows.forms.datagridviewcolumnheadersheightsizemode.autosize;
      this.datagridview1.location = new system.drawing.point(18, 20);
      this.datagridview1.name = "datagridview1";
      this.datagridview1.rowtemplate.height = 23;
      this.datagridview1.size = new system.drawing.size(516, 96);
      this.datagridview1.tabindex = 0;
      // 
      // groupbox5
      // 
      this.groupbox5.controls.add(this.button4);
      this.groupbox5.controls.add(this.datagridview2);
      this.groupbox5.location = new system.drawing.point(12, 281);
      this.groupbox5.name = "groupbox5";
      this.groupbox5.size = new system.drawing.size(568, 162);
      this.groupbox5.tabindex = 6;
      this.groupbox5.tabstop = false;
      this.groupbox5.text = "方式五";
      // 
      // button4
      // 
      this.button4.location = new system.drawing.point(377, 127);
      this.button4.name = "button4";
      this.button4.size = new system.drawing.size(157, 23);
      this.button4.tabindex = 4;
      this.button4.text = "插入一行";
      this.button4.usevisualstylebackcolor = true;
      this.button4.click += new system.eventhandler(this.button4_click);
      // 
      // datagridview2
      // 
      this.datagridview2.columnheadersheightsizemode = system.windows.forms.datagridviewcolumnheadersheightsizemode.autosize;
      this.datagridview2.location = new system.drawing.point(18, 20);
      this.datagridview2.name = "datagridview2";
      this.datagridview2.rowtemplate.height = 23;
      this.datagridview2.size = new system.drawing.size(516, 91);
      this.datagridview2.tabindex = 0;
      // 
      // textbox1
      // 
      this.textbox1.location = new system.drawing.point(18, 20);
      this.textbox1.name = "textbox1";
      this.textbox1.size = new system.drawing.size(157, 21);
      this.textbox1.tabindex = 0;
      // 
      // trackbar1
      // 
      this.trackbar1.location = new system.drawing.point(18, 47);
      this.trackbar1.name = "trackbar1";
      this.trackbar1.size = new system.drawing.size(157, 45);
      this.trackbar1.tabindex = 1;
      // 
      // form2
      // 
      this.autoscaledimensions = new system.drawing.sizef(6f, 12f);
      this.autoscalemode = system.windows.forms.autoscalemode.font;
      this.clientsize = new system.drawing.size(676, 471);
      this.controls.add(this.groupbox5);
      this.controls.add(this.groupbox4);
      this.controls.add(this.groupbox3);
      this.controls.add(this.groupbox2);
      this.controls.add(this.groupbox1);
      this.name = "form2";
      this.text = "form2";
      this.load += new system.eventhandler(this.mainfrm_load);
      this.groupbox1.resumelayout(false);
      this.groupbox1.performlayout();
      this.groupbox2.resumelayout(false);
      this.groupbox2.performlayout();
      this.groupbox3.resumelayout(false);
      this.groupbox3.performlayout();
      this.groupbox4.resumelayout(false);
      ((system.componentmodel.isupportinitialize)(this.datagridview1)).endinit();
      this.groupbox5.resumelayout(false);
      ((system.componentmodel.isupportinitialize)(this.datagridview2)).endinit();
      ((system.componentmodel.isupportinitialize)(this.trackbar1)).endinit();
      this.resumelayout(false);
    }
    #endregion
    private system.windows.forms.groupbox groupbox1;
    private system.windows.forms.groupbox groupbox2;
    private system.windows.forms.button button1;
    private system.windows.forms.textbox textbox2;
    private system.windows.forms.groupbox groupbox3;
    private system.windows.forms.button button2;
    private system.windows.forms.textbox textbox3;
    private system.windows.forms.groupbox groupbox4;
    private system.windows.forms.button button3;
    private system.windows.forms.datagridview datagridview1;
    private system.windows.forms.groupbox groupbox5;
    private system.windows.forms.button button4;
    private system.windows.forms.datagridview datagridview2;
    private system.windows.forms.trackbar trackbar1;
    private system.windows.forms.textbox textbox1;
  }
}