最近一直在做WINFORM项目,所以经常有些新的想法或尝试与大家分享,之前与大家分享了通用窗体遮罩层、通用可附加数据绑定的DataGridView、窗体渐显,今天来分享一个大家在其它软件中常见的功能:数据过滤查询。
先看一下我实现的的整体效果:
过滤之后:
说一下实现上述功能的思路:
首先说一下界面的设计》
1.创建一个窗体(在此称作:过滤窗体FrmFilter),然后在窗体上部放一个DataGridView控件、下面放一个Panel,然后Panel中放两个按钮,至于如何更好的布局或是否需要适应窗体变化,这些都比较简单,在此就不介绍了;
2.设计DataGridView控件,分别加入4列(字段名、运算符、值、值2),其中字段名、运算符列需支持下拉,值、值2列需支持输入
界面设计很简单,现在说一下代码的实现,完整代如下:
using System; using System.Data; using System.Windows.Forms; using TEMS.Service; namespace TEMS.Forms { public partial class FrmFilter : FormBase { private DataTable filterTable = null; /// <summary> /// 获取过滤条件的表格(zuowenjun.cn) /// </summary> public DataTable FilterTable { get { return filterTable; } } public FrmFilter(object source, string text, string value) { InitializeComponent(); dataGridFilter.AutoGenerateColumns = false; var col0 = dataGridFilter.Columns[0] as DataGridViewComboBoxColumn; col0.DataSource = source; col0.DisplayMember = text; col0.ValueMember = value; var col1 = dataGridFilter.Columns[1] as DataGridViewComboBoxColumn; col1.DataSource = FilterOperators.Operators; col1.DisplayMember = "Value"; col1.ValueMember = "Key"; InitFilterDataTable(); } private void InitFilterDataTable() { filterTable = new DataTable(); foreach (DataGridViewColumn col in dataGridFilter.Columns) { filterTable.Columns.Add(col.DataPropertyName,typeof(string)); } dataGridFilter.DataSource = filterTable; } private void btnOk_Click(object sender, EventArgs e) { this.Close(); } private void btnReset_Click(object sender, EventArgs e) { InitFilterDataTable(); this.Close(); } } }
以下是系统自动生成的窗体设计代码:
namespace TEMS.Forms { partial class FrmFilter { /// <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.tableLayoutPanel1 = new System.Windows.Forms.TableLayoutPanel(); this.panel1 = new System.Windows.Forms.Panel(); this.btnReset = new System.Windows.Forms.Button(); this.btnOk = new System.Windows.Forms.Button(); this.dataGridFilter = new System.Windows.Forms.DataGridView(); this.name = new System.Windows.Forms.DataGridViewComboBoxColumn(); this.operators = new System.Windows.Forms.DataGridViewComboBoxColumn(); this.value = new System.Windows.Forms.DataGridViewTextBoxColumn(); this.value2 = new System.Windows.Forms.DataGridViewTextBoxColumn(); this.tableLayoutPanel1.SuspendLayout(); this.panel1.SuspendLayout(); ((System.ComponentModel.ISupportInitialize)(this.dataGridFilter)).BeginInit(); this.SuspendLayout(); // // tableLayoutPanel1 // this.tableLayoutPanel1.ColumnCount = 1; this.tableLayoutPanel1.ColumnStyles.Add(new System.Windows.Forms.ColumnStyle()); this.tableLayoutPanel1.Controls.Add(this.panel1, 0, 1); this.tableLayoutPanel1.Controls.Add(this.dataGridFilter, 0, 0); this.tableLayoutPanel1.Dock = System.Windows.Forms.DockStyle.Fill; this.tableLayoutPanel1.Location = new System.Drawing.Point(0, 0); this.tableLayoutPanel1.Name = "tableLayoutPanel1"; this.tableLayoutPanel1.RowCount = 2; this.tableLayoutPanel1.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 90F)); this.tableLayoutPanel1.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 10F)); this.tableLayoutPanel1.Size = new System.Drawing.Size(598, 436); this.tableLayoutPanel1.TabIndex = 0; // // panel1 // this.panel1.Controls.Add(this.btnReset); this.panel1.Controls.Add(this.btnOk); this.panel1.Dock = System.Windows.Forms.DockStyle.Fill; this.panel1.Location = new System.Drawing.Point(3, 395); this.panel1.Name = "panel1"; this.panel1.Size = new System.Drawing.Size(592, 38); this.panel1.TabIndex = 0; // // btnReset // this.btnReset.Anchor = ((System.Windows.Forms.AnchorStyles)(((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom) | System.Windows.Forms.AnchorStyles.Right))); this.btnReset.Location = new System.Drawing.Point(508, 6); this.btnReset.Name = "btnReset"; this.btnReset.Size = new System.Drawing.Size(75, 23); this.btnReset.TabIndex = 0; this.btnReset.Text = "重 置"; this.btnReset.UseVisualStyleBackColor = true; this.btnReset.Click += new System.EventHandler(this.btnReset_Click); // // btnOk // this.btnOk.Anchor = ((System.Windows.Forms.AnchorStyles)(((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom) | System.Windows.Forms.AnchorStyles.Right))); this.btnOk.Location = new System.Drawing.Point(427, 6); this.btnOk.Name = "btnOk"; this.btnOk.Size = new System.Drawing.Size(75, 23); this.btnOk.TabIndex = 0; this.btnOk.Text = "确 定"; this.btnOk.UseVisualStyleBackColor = true; this.btnOk.Click += new System.EventHandler(this.btnOk_Click); // // dataGridFilter // this.dataGridFilter.ColumnHeadersHeightSizeMode = System.Windows.Forms.DataGridViewColumnHeadersHeightSizeMode.AutoSize; this.dataGridFilter.Columns.AddRange(new System.Windows.Forms.DataGridViewColumn[] { this.name, this.operators, this.value, this.value2}); this.dataGridFilter.Dock = System.Windows.Forms.DockStyle.Fill; this.dataGridFilter.Location = new System.Drawing.Point(3, 3); this.dataGridFilter.Name = "dataGridFilter"; this.dataGridFilter.RowTemplate.Height = 23; this.dataGridFilter.Size = new System.Drawing.Size(592, 386); this.dataGridFilter.TabIndex = 1; // // name // this.name.AutoSizeMode = System.Windows.Forms.DataGridViewAutoSizeColumnMode.Fill; this.name.DataPropertyName = "name"; this.name.FillWeight = 80F; this.name.HeaderText = "字段名"; this.name.Name = "name"; // // operators // this.operators.DataPropertyName = "operators"; this.operators.HeaderText = "运算符"; this.operators.Name = "operators"; // // value // this.value.AutoSizeMode = System.Windows.Forms.DataGridViewAutoSizeColumnMode.Fill; this.value.DataPropertyName = "value"; this.value.HeaderText = "值"; this.value.Name = "value"; // // value2 // this.value2.AutoSizeMode = System.Windows.Forms.DataGridViewAutoSizeColumnMode.Fill; this.value2.DataPropertyName = "value2"; this.value2.HeaderText = "值2"; this.value2.Name = "value2"; // // FrmFilter // this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 12F); this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font; this.ClientSize = new System.Drawing.Size(598, 436); this.Controls.Add(this.tableLayoutPanel1); this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedDialog; this.MaximizeBox = false; this.Name = "FrmFilter"; this.Opacity = 1D; this.ShowInTaskbar = false; this.StartPosition = System.Windows.Forms.FormStartPosition.CenterParent; this.Text = "筛选查询"; this.tableLayoutPanel1.ResumeLayout(false); this.panel1.ResumeLayout(false); ((System.ComponentModel.ISupportInitialize)(this.dataGridFilter)).EndInit(); this.ResumeLayout(false); } #endregion private System.Windows.Forms.TableLayoutPanel tableLayoutPanel1; private System.Windows.Forms.Panel panel1; private System.Windows.Forms.Button btnReset; private System.Windows.Forms.Button btnOk; private System.Windows.Forms.DataGridView dataGridFilter; private System.Windows.Forms.DataGridViewComboBoxColumn name; private System.Windows.Forms.DataGridViewComboBoxColumn operators; private System.Windows.Forms.DataGridViewTextBoxColumn value; private System.Windows.Forms.DataGridViewTextBoxColumn value2; } }
构造函数中的的 FilterOperators.Operators表示的是运算符的数据源,我是定义的一个struct,如下:
public struct FilterOperators { public const string Equal = "Equal"; public const string NotEqual = "NotEqual"; public const string LessThan = "LessThan"; public const string GreaterThan = "GreaterThan"; public const string LessThanOrEqual = "LessThanOrEqual"; public const string GreaterThanOrEqual = "GreaterThanOrEqual"; public const string Contains = "Contains"; public const string StartsWith = "StartsWith"; public const string EndsWith = "EndsWith"; public const string Between = "Between"; public static KeyValueList<string, string> Operators = new KeyValueList<string, string>() { {Equal,"等于"},{NotEqual,"不等于"}, {LessThan,"小于"},{GreaterThan,"大于"}, {LessThanOrEqual,"小于或等于"},{GreaterThanOrEqual,"大于或等于"}, {Contains,"包含"},{StartsWith,"开头包含"},{EndsWith,"结尾包含"}, {Between,"区间"} }; }
FilterTable属性是用来获取过滤条件的表格,表格的数据是通过绑定DataGridView控件来获得的,如果不知道为什么通过数据源绑定到一个空表格就能获取数据,请查找相关资料,这里不作说明,当然也可以通过评论与我交流。
以上都是关于过滤窗体的实现,下面我要讲解最关键字部份,也是最重要的部份,就是:如何将获得的过滤条件DataTable转换成查询语句,这里的查询语句包括SQL或表达式树,由于是通过的过滤窗体,所以关于生成查询条件语句我放在了调用完该窗体后来实现,当然如果大家只用一种方式(实体类或表),可以直接集成在窗体类中,直接返回生成的查询语句即可。
因为我项目中用的是实体类来查询,所以我采用动态生成Lambda表达式树,然后借助PredicateBuilder类(这是别人开发的类,详见我之前的博文)进行拼接,最后生成用于查询的表达式树,实现代码如下:
/// <summary> /// 获取查询表达式树(核心代码,这个方法生成的表达式树如:t.ID==1) (zuowenjun.cn) /// </summary> /// <typeparam name="TEntity"></typeparam> /// <param name="fieldName"></param> /// <param name="operatorName"></param> /// <param name="value"></param> /// <param name="value2"></param> /// <returns></returns> public static Expression<Func<TEntity, bool>> GetQueryExpression<TEntity>(string fieldName, string operatorName, string value, string value2) where TEntity : class { PropertyInfo fieldInfo = typeof(TEntity).GetProperty(fieldName, BindingFlags.Instance | BindingFlags.Public | BindingFlags.IgnoreCase); Type pType = fieldInfo.PropertyType; if (string.IsNullOrEmpty(operatorName)) { throw new ArgumentException("运算符不能为空!", "operatorName"); } if (!value.CanConvert(pType)) { throw new ArgumentException(string.Format("【{0}】的查询值类型不正确,必须为{1}类型!", General.GetDisplayName(fieldInfo), pType.FullName), "value"); } if (operatorName == FilterOperators.Between && !value2.CanConvert(pType)) { throw new ArgumentException(string.Format("【{0}】的查询值2类型不正确,必须为{1}类型!", General.GetDisplayName(fieldInfo), pType.FullName), "value"); } dynamic convertedValue = Convert.ChangeType(value, pType); ParameterExpression expParameter = Expression.Parameter(typeof(TEntity), "f"); MemberExpression expl = Expression.Property(expParameter, fieldInfo); ConstantExpression expr = Expression.Constant(convertedValue, pType); Expression expBody=null; Type expType = typeof(Expression); var expMethod = expType.GetMethod(operatorName, new[] { expType, expType }); if (expMethod != null) { expBody = (Expression)expMethod.Invoke(null, new object[] { expl, expr }); } else if (FilterOperators.Between == operatorName) { dynamic convertedValue2 = Convert.ChangeType(value2, pType); ConstantExpression expr2 = Expression.Constant(convertedValue2, pType); expBody = Expression.GreaterThanOrEqual(expl, expr); expBody = Expression.AndAlso(expBody, Expression.LessThanOrEqual(expl, expr2)); } else if (new[] { FilterOperators.Contains, FilterOperators.StartsWith, FilterOperators.EndsWith }.Contains(operatorName)) { expBody = Expression.Call(expl, typeof(string).GetMethod(operatorName, new Type[] { typeof(string) }), expr); } else { throw new ArgumentException("无效的运算符!", "operatorName"); } Expression<Func<TEntity, bool>> lamExp = Expression.Lambda<Func<TEntity, bool>>(expBody, expParameter); return lamExp; }
以下是具体的调用:
//获取用于过滤的字段(这里直接采用数据列表的相应列,大家可以生成相应的List数据源) (zuowenjun.cn) private List<DataGridViewColumn> GetQueryGridColumnInfos() { List<DataGridViewColumn> cols = new List<DataGridViewColumn>(); for (int i = 0; i < dataGridBase.Columns.Count - 3; i++) { cols.Add(dataGridBase.Columns[i]); } return cols; } //工具栏点击过滤查询按钮事件 (zuowenjun.cn) private void ToolStrip_OnFilter(object sender, EventArgs e) { if (filterForm == null) { filterForm = new FrmFilter(GetQueryGridColumnInfos(), "HeaderText", "DataPropertyName"); } filterForm.ShowDialog(Common.MainForm); whereExpr = PredicateBuilder.True<Category>(); var p = whereExpr.Parameters[0]; foreach (DataRow row in filterForm.FilterTable.Rows) { string fieldName = row[0].ToString(); string opt = row[1].ToString(); string value = row[2].ToString(); string value2 = row[3].ToString(); var fieldExpr = Common.GetQueryExpression<Category>(fieldName, opt, value, value2);//动态生成查询表达式树 whereExpr = whereExpr.And(fieldExpr);//连接表达式树 } FirstLoadList();//加载数据并显示 } ///加载数据 (zuowenjun.cn) private void FirstLoadList() { int recordCount = 0; base.PageInfo = new PageInfo(); base.PageInfo.PageSize = 10; base.PageInfo.CurrentPageNo = 1; var resultList = QueryBusiness<Category>.GetListByPage(whereExpr, t => t, t => t.ID, 1, base.PageInfo.PageSize, base.PageInfo.CurrentPageNo, out recordCount); base.PageInfo.RecordCount = recordCount; base.AppendDataToGrid(resultList,false); }
由于代码较多,且使用了一些其它的编写好的类,若有不明白的地方,可以在此文下评论,我会帮忙解答,希望能帮到大家,不足之处也欢迎大家指证,谢谢!