1.默认EF生成的连接字符串比较的长和怪异，若想使用普通的连接字符串来连接EF，则可以通过创建分部类，并重写一个构造函数，在构造函数中通过动态拼接EntityConnectionString得到EF所需的连接字符串，具代实现代码如下：
class="brush:csharp;gutter:true;"> public partial class DataEntities
{
private static ConcurrentDictionary<string, string> entityConnStrings = new ConcurrentDictionary<string, string>();
public DataEntities(string connName)
: base(BuildEntityConnectionString(connName))
{
}
private static string BuildEntityConnectionString(string connName)
{
if (!entityConnStrings.ContainsKey(connName))
{
var connStrSetting = System.Configuration.ConfigurationManager.ConnectionStrings[connName];
EntityConnectionStringBuilder entityConnStrBuilder = new EntityConnectionStringBuilder();
entityConnStrBuilder.Provider = connStrSetting.ProviderName;
entityConnStrBuilder.ProviderConnectionString = EncryptUtility.DesDecrypt("XXXXX", connStrSetting.ConnectionString);
entityConnStrBuilder.Metadata = "res://*/Data.csdl|res://*/Data.ssdl|res://*/Data.msl";
string entityConnString = entityConnStrBuilder.ToString();
entityConnStrings.AddOrUpdate(connName, entityConnString, (key, value) => entityConnString);
}
return entityConnStrings[connName];
}
}
注意上面的类是一个分部类：partial，同时BuildEntityConnectionString方法是一个静态方法，在BuildEntityConnectionString方法中ProviderConnectionString = EncryptUtility.DesDecrypt("XXXXX", connStrSetting.ConnectionString);是关键，我这里是对config中的连接字符串 也都进行了加密，故此处我需要解密，若无这个需求可以直接：ProviderConnectionString =connStrSetting.ConnectionString即可。后续实例化EF上下文对象时，请使用：DataEntities(string connName)这个构造涵数即可，DataEntities是具体的EF上下文对象，大家的EF上下文类名均可能不相同。
2.支持一个通用对象的XML序列化（即：一个类中有可变类型属性成员，需要不同的序列结果及生成不同的序列元素名称），具体实现代码如下：
一个需要被序列化成XML的类：其中要求生成的XML元素detail必需有子元素，且子元素名称及子元素内部属性根据类型的不同而不同（即：detail元素下的子元素是可变的）
[XmlRootAttribute("master")]
public class DemoMaster<T> where T : class
{
[XmlElement("attr")]
public string DemoAttr { get; set; }
[XmlElement("detail")]
public DemoDetail<T> DemoDetail { get; set; } //关键点在这里，该属性元素为：detail，但其子元素根据T不同而不同
}
public class DemoDetail<T> : IXmlSerializable where T : class
{
public T body { get; set; }
public System.Xml.Schema.XmlSchema GetSchema()
{
return null;
}
public void ReadXml(System.Xml.XmlReader reader)
{
string bodyStr = reader.ReadInnerXml();
this.body = XmlHelper.XmlDeserialize<T>(bodyStr, Encoding.UTF8);
}
public void WriteXml(System.Xml.XmlWriter writer)
{
writer.WriteRaw(XmlHelper.XmlSerialize(this.body, Encoding.UTF8, true));
}
}
[XmlTypeAttribute("list-a", AnonymousType = false)]
public class DemoDetailA
{
public string Apro1 { get; set; }
public string Apro2 { get; set; }
public string Apro3 { get; set; }
}
[XmlTypeAttribute("list-b", AnonymousType = false)]
public class DemoDetailB
{
public string Bpro1 { get; set; }
public string Bpro2 { get; set; }
public string Bpro3 { get; set; }
}
[XmlTypeAttribute("list-c", AnonymousType = false)]
public class DemoDetailC
{
public string Cpro1 { get; set; }
public string Cpro2 { get; set; }
public string Cpro3 { get; set; }
}
注意上面代码中，需要关注：DemoDetail属性及DemoDetail<T>类，DemoDetail属性仅是为了生成detail元素节点，而子节点则由DemoDetail<T>类来进行生成，DemoDetail<T>是实现了IXmlSerializable接口，在XML序列化时，DemoDetail<T>类仅将body属性对应的T类型实例内容进行序列化（WriteRaw），而反序列化时，则先反序列化body属性对应的T类型实例，然后赋值给body属性，这也是巧妙之处，DemoDetail<T>类本身并没有真正参与到序列化中，故序列化的字符串也看不到DemoDetail<T>类相关的元素，DemoDetail<T>类仅仅是一个XML序列化格式生成的中介。序列化的XML结果如下：
序列化代码：
var demo1 = new DemoMaster<DemoDetailA>()
{
DemoAttr = "demo1",
DemoDetail = new DemoDetail<DemoDetailA>() { body = new DemoDetailA() { Apro1 = "demoA1", Apro2 = "demoA2", Apro3 = "demoA3" } }
};
var demo2 = new DemoMaster<DemoDetailB>()
{
DemoAttr = "demo2",
DemoDetail = new DemoDetail<DemoDetailB>() { body = new DemoDetailB() { Bpro1 = "demoB1", Bpro2 = "demoB2", Bpro3 = "demoB3" } }
};
var demo3 = new DemoMaster<DemoDetailC>()
{
DemoAttr = "demo3",
DemoDetail = new DemoDetail<DemoDetailC>() { body = new DemoDetailC() { Cpro1 = "demoC1", Cpro2 = "demoC2", Cpro3 = "demoC3" } }
};
textBox1.Text = XmlHelper.XmlSerialize(demo1, Encoding.UTF8);
textBox1.Text += "\r\n" + XmlHelper.XmlSerialize(demo2, Encoding.UTF8);
textBox1.Text += "\r\n" + XmlHelper.XmlSerialize(demo3, Encoding.UTF8);
序列化的XML:
<?xml version="1.0" encoding="utf-8"?>
<master>
<attr>demo1</attr>
<detail><list-a>
<Apro1>demoA1</Apro1>
<Apro2>demoA2</Apro2>
<Apro3>demoA3</Apro3>
</list-a></detail>
</master>
<?xml version="1.0" encoding="utf-8"?>
<master>
<attr>demo2</attr>
<detail><list-b>
<Bpro1>demoB1</Bpro1>
<Bpro2>demoB2</Bpro2>
<Bpro3>demoB3</Bpro3>
</list-b></detail>
</master>
<?xml version="1.0" encoding="utf-8"?>
<master>
<attr>demo3</attr>
<detail><list-c>
<Cpro1>demoC1</Cpro1>
<Cpro2>demoC2</Cpro2>
<Cpro3>demoC3</Cpro3>
</list-c></detail>
</master>
3.winform DataGridView 实现指定列采取密码框模式显示与编辑，以及列绑定到复合属性（即：绑定到多层次属性），具体实现代码如下：
dataGridView1.CellFormatting += new DataGridViewCellFormattingEventHandler(dataGridView1_CellFormatting);
dataGridView1.EditingControlShowing += new DataGridViewEditingControlShowingEventHandler(dataGridView1_EditingControlShowing);
public string EvaluateValue(object obj, string property)
{
string retValue = string.Empty;
string[] names = property.Split('.');
for (int i = 0; i < names.Count(); i++)
{
try
{
var prop = obj.GetType().GetProperty(names[i]);
var result = prop.GetValue(obj, null);
if (result != null)
{
obj = result;
retValue = result.ToString();
}
else
{
break;
}
}
catch (Exception)
{
throw;
}
}
return retValue;
}
private void dataGridView1_CellFormatting(object sender, DataGridViewCellFormattingEventArgs e)
{
if (dataGridView1.Columns[e.ColumnIndex].DataPropertyName.Contains("."))
{
e.Value = EvaluateValue(dataGridView1.Rows[e.RowIndex].DataBoundItem, dataGridView1.Columns[e.ColumnIndex].DataPropertyName);
}
if (dataGridView1.Columns[e.ColumnIndex].Name == "KeyCode")
{
if (e.Value != null && e.Value.ToString().Length > 0)
{
e.Value = new string('*', e.Value.ToString().Length);
}
}
}
private void dataGridView1_EditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e)
{
int i = this.dataGridView1.CurrentCell.ColumnIndex;
bool usePassword = false;
if (dataGridView1.Columns[i].Name == "KeyCode")
{
usePassword = true;
}
TextBox txt = e.Control as TextBox;
if (txt != null)
{
txt.UseSystemPasswordChar = usePassword;
}
}
//示例：绑定的源数据类定义
public class DemoBindClass
{
public string Attr { get; set; }
public string KeyCode { get; set; }
public DemoDetailA Detail { get; set; }
}
public class DemoDetailA
{
public string Apro1 { get; set; }
public string Apro2 { get; set; }
public string Apro3 { get; set; }
public DemoDetailB DetailChild { get; set; }
}
public class DemoDetailB
{
public string Bpro1 { get; set; }
public string Bpro2 { get; set; }
public string Bpro3 { get; set; }
}
绑定到数据源：
var demo = new[] {
new DemoBindClass()
{
Attr = "demo",
KeyCode="a123456789b",
Detail = new DemoDetailA()
{
Apro1 = "demoA1",
Apro2 = "demoA2",
Apro3 = "demoA3",
DetailChild = new DemoDetailB()
{
Bpro1 = "demoB1",
Bpro2 = "demoB2",
Bpro3 = "demoB3"
}
}
}
};
dataGridView1.AutoGenerateColumns = false;
dataGridView1.DataSource = demo;
实现指定列采取密码框模式显示与编辑，以及列绑定到复合属性均需要订阅DataGridView的CellFormatting及EditingControlShowing事件，并在其中写转换当前Cell的Value，实现列绑定到复合属性，关键点在：EvaluateValue方法，该方法逻辑很简单，就是根据绑定的属性层级（.分隔）层层遍历获取属性的值，直到遍历完或为空时停止，最后得到的结果即是绑定的属性的值。最终实现的效果如下图示：
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