本文实例讲述了C#中DataBindings用法。分享给大家供大家参考,具体如下: 在C#操作数据库过程中,针对一般的文本控件,比如TextBox,Label等,我们赋值直接使用类似TextBox.Text=****的方式来
本文实例讲述了C#中DataBindings用法。分享给大家供大家参考,具体如下:
在C#操作数据库过程中,针对一般的文本控件,比如TextBox,Label等,我们赋值直接使用类似TextBox.Text=****的方式来进行,这种方式从某种意义上来说的确是最简便的方式,但是对于复杂一些的空间,比如说DataGridView,这个时候,绑定数据源我们一般使用DataGridView1.DataSource=****的方式来进行,如果数据源稍微有更改,那么只需要重新调用绑定一遍即可。可以说这种方式是单向的,也即从数据库到UI,但是有没有一种方式能够实现数据源改变的时候,不用重新绑定DataGridView就让它能够自动刷新数据呢,当然,这里要提到的就是DataBinding了。
代码如下
Form2.cs代码:
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; } } }
Form2.Designer.cs代码:
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; } }
效果图:
更多关于C#相关内容感兴趣的读者可查看本站专题:《C#常见控件用法教程》、《WinForm控件用法总结》、《C#数据结构与算法教程》、《C#面向对象程序设计入门教程》及《C#程序设计之线程使用技巧总结》
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