前言

     之前在 “使用T4模板生成代码 - 初探” 文章简单的使用了T4模板的生成功能，但对于一个模板生成多个实例文件，如何实现这个方式呢？无意发现一个解决方案 “MultipleOutputHelper.ttinclude” ，它让基于T4模板批量生成文件实例变得简单起来了。

 什么是MultipleOutputHelper.ttinclude

     Damien Guard是一个在加利福尼亚州圣何塞的开发人员，他构建出处理使用T4模板输出多文件的解决方案“MultipleOutputHelper.ttinclude”

 使用

      1. 初始化

     获取MultipleOutputHelper.ttinclude文件模板

     注意： 文件可以上github.com 托管上面获取（ https://github.com/damieng/DamienGKit/tree/master/T4/MultipleOutputHelper）

     在T4模板中使用include指令导入MultipleOutputHelper.ttinclude文件或者将MultipleOutputHelper.ttinclude的代码复制在T4模板内。

     然后初始化Manager对象,代码如下：

     注意： 这里的Manager.ttinclude 就是MultipleOutputHelper.ttinclude文件模板     

     2. 文件块

     使用代码标识区分生成的代码块的范围

     该代码声明了一个Employee.generated.cs文件，文件代码内容为：

     3. 页眉和页脚

     很多模板需要共享一个共同的页眉和页脚时，可以使用import语句进行打开和关闭。简单的使用StartHeader和StartFooter的代码方法进行分割。

     4. 编译执行

    使用Process方法，进行文件分割。

  场景应用

    基于之前的“使用T4模板生成代码 - 初探” 文章的场景，进行基于NHibernate Mapper 来获取Domain对象，然后进行批量生成多个代码文件。

    1. 自定义T4模板，文件名为“EntityRepositoryTemplate.tt”，代码如下：

     输出文件效果：

 让程序自动执行基于T4文件的编译工作

   在MSDN-”演练：创建自定义文本模板宿主“ 文章里面看到一段代码，进行了T4文件的编译工作,代码如下：

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347

using System; using System.IO; using System.CodeDom.Compiler; using System.Collections.Generic; using System.Text; using Microsoft.VisualStudio.TextTemplating;   namespace CustomHost {     //The text template transformation engine is responsible for running     //the transformation process.     //The host is responsible for all input and output, locating files,     //and anything else related to the external environment.     //-------------------------------------------------------------------------     class CustomCmdLineHost : ITextTemplatingEngineHost     {         //the path and file name of the text template that is being processed         //---------------------------------------------------------------------         internal string TemplateFileValue;         public string TemplateFile         {             get { return TemplateFileValue; }         }         //This will be the extension of the generated text output file.         //The host can provide a default by setting the value of the field here.         //The engine can change this value based on the optional output directive         //if the user specifies it in the text template.         //---------------------------------------------------------------------         private string fileExtensionValue = ".txt";         public string FileExtension         {             get { return fileExtensionValue; }         }         //This will be the encoding of the generated text output file.         //The host can provide a default by setting the value of the field here.         //The engine can change this value based on the optional output directive         //if the user specifies it in the text template.         //---------------------------------------------------------------------         private Encoding fileEncodingValue = Encoding.UTF8;         public Encoding FileEncoding         {             get { return fileEncodingValue; }         }         //These are the errors that occur when the engine processes a template.         //The engine passes the errors to the host when it is done processing,         //and the host can decide how to display them. For example, the host         //can display the errors in the UI or write them to a file.         //---------------------------------------------------------------------         private CompilerErrorCollection errorsValue;         public CompilerErrorCollection Errors         {             get { return errorsValue; }         }         //The host can provide standard assembly references.         //The engine will use these references when compiling and         //executing the generated transformation class.         //--------------------------------------------------------------         public IList<string> StandardAssemblyReferences         {             get             {                 return new string[]                 {                     //If this host searches standard paths and the GAC,                     //we can specify the assembly name like this.                     //---------------------------------------------------------                     //"System"                       //Because this host only resolves assemblies from the                     //fully qualified path and name of the assembly,                     //this is a quick way to get the code to give us the                     //fully qualified path and name of the System assembly.                     //---------------------------------------------------------                     typeof(System.Uri).Assembly.Location                 };             }         }         //The host can provide standard imports or using statements.         //The engine will add these statements to the generated         //transformation class.         //--------------------------------------------------------------         public IList<string> StandardImports         {             get             {                 return new string[]                 {                     "System"                 };             }         }         //The engine calls this method based on the optional include directive         //if the user has specified it in the text template.         //This method can be called 0, 1, or more times.         //---------------------------------------------------------------------         //The included text is returned in the context parameter.         //If the host searches the registry for the location of include files,         //or if the host searches multiple locations by default, the host can         //return the final path of the include file in the location parameter.         //---------------------------------------------------------------------         public bool LoadIncludeText(string requestFileName, out string content, out string location)         {             content = System.String.Empty;             location = System.String.Empty;                      //If the argument is the fully qualified path of an existing file,             //then we are done.             //----------------------------------------------------------------             if (File.Exists(requestFileName))             {                 content = File.ReadAllText(requestFileName);                 return true;             }             //This can be customized to search specific paths for the file.             //This can be customized to accept paths to search as command line             //arguments.             //----------------------------------------------------------------             else             {                 return false;             }         }         //Called by the Engine to enquire about         //the processing options you require.         //If you recognize that option, return an         //appropriate value.         //Otherwise, pass back NULL.         //--------------------------------------------------------------------         public object GetHostOption(string optionName)         {         object returnObject;         switch (optionName)         {         case "CacheAssemblies":                     returnObject = true;      break;         default:         returnObject = null;         break;         }         return returnObject;         }         //The engine calls this method to resolve assembly references used in         //the generated transformation class project and for the optional         //assembly directive if the user has specified it in the text template.         //This method can be called 0, 1, or more times.

鲜花

握手

雷人

路过

鸡蛋

该文章已有0人参与评论

请发表评论

评论

全部评论