搜索
首页数据库mysql教程[Access] C#通过COM组件访问Access文件

[Access] C#通过COM组件访问Access文件

Jun 07, 2016 pm 03:37 PM
accesscomd文件组件访问说明通过采用

说明: 1,采用dynamic调用COM组件,适用于.NET 4.0以上支持dynamic版本的才可以; 2,执行速度不敢恭维,只是因为要用于Silverlight OOB模式中才研究一二; 3,测试环境 .net 4.5 + Silverlight 5.0 + Visual Studio 2013 4,见如下helper类(需引用 using

说明:

1,采用dynamic调用COM组件,适用于.NET 4.0以上支持dynamic版本的才可以;

2,执行速度不敢恭维,只是因为要用于Silverlight OOB模式中才研究一二;

3,测试环境.net 4.5 + Silverlight 5.0 + Visual Studio 2013

4,见如下helper类(需引用using System.Runtime.InteropServices.Automation;):

[Access] C#通过COM组件访问Access文件[Access] C#通过COM组件访问Access文件

<span>  1</span> <span>public</span> <span>class</span><span> SLAccessHelper
</span><span>  2</span> <span>{
</span><span>  3</span>     <span>private</span> dynamic m_AccessApp;<span>//</span><span> Access.Application</span>
<span>  4</span>     <span>private</span> dynamic m_Database;<span>//</span><span> Database</span>
<span>  5</span>     <span>private</span><span> dynamic m_Recordset;
</span><span>  6</span> 
<span>  7</span>     <span>///</span> <span><summary></summary></span>
<span>  8</span>     <span>///</span><span> 构造函数
</span><span>  9</span>     <span>///</span> <span></span>
<span> 10</span>     <span>///</span> <span><param name="visible"></span><span>Access是否可见</span><span></span>
<span> 11</span>     <span>public</span> SLAccessHelper(<span>bool</span><span> visible)
</span><span> 12</span> <span>    {
</span><span> 13</span>         m_AccessApp = AutomationFactory.CreateObject(<span>"</span><span>Access.Application</span><span>"</span><span>);
</span><span> 14</span>         m_AccessApp.Visible =<span> visible;
</span><span> 15</span> <span>    }
</span><span> 16</span> 
<span> 17</span>     <span>///</span> <span><summary></summary></span>
<span> 18</span>     <span>///</span><span> 打开数据库
</span><span> 19</span>     <span>///</span> <span></span>
<span> 20</span>     <span>///</span> <span><param name="filePath"></span><span>Access数据库文件路径</span><span></span>
<span> 21</span>     <span>///</span> <span><param name="exclusive"></span><span>是否共享</span><span></span>
<span> 22</span>     <span>///</span> <span><param name="bstrPassword"></span><span>密码</span><span></span>
<span> 23</span>     <span>public</span> <span>void</span> OpenDb(<span>string</span> filePath, <span>bool</span> exclusive = <span>false</span>, <span>string</span> bstrPassword = <span>""</span><span>)
</span><span> 24</span> <span>    {
</span><span> 25</span> <span>        m_AccessApp.OpenCurrentDatabase(filePath, exclusive, bstrPassword);
</span><span> 26</span>         m_Database =<span> m_AccessApp.CurrentDb();
</span><span> 27</span> <span>    }
</span><span> 28</span> 
<span> 29</span>     <span>///</span> <span><summary></summary></span>
<span> 30</span>     <span>///</span><span> 获取当前数据库中所有表名称集合
</span><span> 31</span>     <span>///</span> <span></span>
<span> 32</span>     <span>///</span> <span><returns></returns></span><span>所有表名称集合</span><span></span>
<span> 33</span>     <span>public</span> Liststring><span> GetTableNames()
</span><span> 34</span> <span>    {
</span><span> 35</span>         Liststring> tableNames = <span>new</span> Liststring><span>();
</span><span> 36</span>         dynamic tableDefs =<span> m_Database.TableDefs;
</span><span> 37</span>         <span>foreach</span> (dynamic tableDef <span>in</span><span> tableDefs)
</span><span> 38</span> <span>        {
</span><span> 39</span> <span>            tableNames.Add(tableDef.Name);
</span><span> 40</span> <span>        }
</span><span> 41</span> 
<span> 42</span>         <span>return</span><span> tableNames;
</span><span> 43</span> <span>    }
</span><span> 44</span> 
<span> 45</span>     <span>///</span> <span><summary></summary></span>
<span> 46</span>     <span>///</span><span> 加载表数据
</span><span> 47</span>     <span>///</span> <span></span>
<span> 48</span>     <span>///</span> <span><param name="tableName"></span><span>表名称</span><span></span>
<span> 49</span>     <span>///</span> <span><returns></returns></span><span>表数据</span><span></span>
<span> 50</span>     <span>public</span> List<list>string>> LoadTable(<span>string</span><span> tableName)
</span><span> 51</span> <span>    {
</span><span> 52</span>         dynamic recordSet =<span> m_Database.OpenRecordset(tableName);
</span><span> 53</span>         <span>int</span> fieldsCount =<span> recordSet.Fields.Count;
</span><span> 54</span>         List<list>string>> data = <span>new</span> List<list>string>><span>();
</span><span> 55</span>         <span>if</span> (fieldsCount > <span>0</span><span>)
</span><span> 56</span> <span>        {
</span><span> 57</span>             <span>try</span>
<span> 58</span> <span>            {
</span><span> 59</span>                 Liststring> fieldNames = <span>new</span> Liststring><span>();
</span><span> 60</span>                 <span>for</span> (<span>int</span> i = <span>0</span>; i )
<span> 61</span> <span>                {
</span><span> 62</span> <span>                    fieldNames.Add(recordSet.Fields[i].Name);
</span><span> 63</span> <span>                }
</span><span> 64</span> <span>                data.Add(fieldNames);
</span><span> 65</span>                 <span>if</span> (!<span>recordSet.EOF)
</span><span> 66</span> <span>                {
</span><span> 67</span> <span>                    recordSet.MoveFirst();
</span><span> 68</span>                     <span>while</span> (!<span>recordSet.EOF)
</span><span> 69</span> <span>                    {
</span><span> 70</span>                         <span>object</span>[] dataRow = recordSet.GetRows();<span>//</span><span> 返回一维数组</span>
<span> 71</span>                         Liststring> dataRowStr = <span>new</span> Liststring><span>();
</span><span> 72</span>                         <span>for</span> (<span>int</span> i = <span>0</span>; i )
<span> 73</span> <span>                        {
</span><span> 74</span>                             dataRowStr.Add(dataRow[i] == <span>null</span> ? <span>""</span><span> : dataRow[i].ToString());
</span><span> 75</span> <span>                        }
</span><span> 76</span> <span>                        data.Add(dataRowStr);
</span><span> 77</span> <span>                    }
</span><span> 78</span> <span>                }
</span><span> 79</span> <span>            }
</span><span> 80</span>             <span>catch</span><span> (Exception ex)
</span><span> 81</span> <span>            {
</span><span> 82</span>                 <span>throw</span> <span>new</span><span> Exception(ex.Message);
</span><span> 83</span> <span>            }
</span><span> 84</span>             <span>finally</span>
<span> 85</span> <span>            {
</span><span> 86</span>                 <span>if</span> (recordSet != <span>null</span><span>)
</span><span> 87</span> <span>                {
</span><span> 88</span> <span>                    recordSet.Close();
</span><span> 89</span> <span>                    ((IDisposable)recordSet).Dispose();
</span><span> 90</span>                     recordSet = <span>null</span><span>;
</span><span> 91</span> <span>                }
</span><span> 92</span> <span>            }
</span><span> 93</span> <span>        }
</span><span> 94</span> 
<span> 95</span>         <span>return</span><span> data;
</span><span> 96</span> <span>    }
</span><span> 97</span> 
<span> 98</span>     <span>///</span> <span><summary></summary></span>
<span> 99</span>     <span>///</span><span> 添加新纪录
</span><span>100</span>     <span>///</span> <span></span>
<span>101</span>     <span>///</span> <span><param name="tableName"></span><span>表格名称</span><span></span>
<span>102</span>     <span>///</span> <span><param name="data"></span><span>数据</span><span></span>
<span>103</span>     <span>public</span> <span>void</span> AddNewRecord(<span>string</span> tableName, List<dictionary>string, <span>object</span>>><span> data)
</span><span>104</span> <span>    {
</span><span>105</span>         <span>try</span>
<span>106</span> <span>        {
</span><span>107</span>             m_Recordset = m_Database.OpenRecordset(tableName, <span>1</span>);<span>//</span><span> 1=RecordsetTypeEnum.dbOpenTable</span>
<span>108</span>             <span>int</span> fieldsCount =<span> m_Recordset.Fields.Count;
</span><span>109</span>             Liststring> fieldNames = <span>new</span> Liststring><span>();
</span><span>110</span>             <span>for</span> (<span>int</span> i = <span>0</span>; i )
<span>111</span> <span>            {
</span><span>112</span> <span>                fieldNames.Add(m_Recordset.Fields[i].Name);
</span><span>113</span> <span>            }
</span><span>114</span>             <span>for</span> (<span>int</span> rowIndex = <span>0</span>; rowIndex )
<span>115</span> <span>            {
</span><span>116</span> <span>                m_Recordset.AddNew();
</span><span>117</span>                 <span>foreach</span> (<span>string</span> fieldName <span>in</span><span> fieldNames)
</span><span>118</span> <span>                {
</span><span>119</span>                     m_Recordset.Fields[fieldName].Value =<span> data[rowIndex][fieldName];
</span><span>120</span> <span>                }
</span><span>121</span> <span>                m_Recordset.Update();
</span><span>122</span> <span>            }
</span><span>123</span> <span>        }
</span><span>124</span>         <span>catch</span><span>(Exception ex)
</span><span>125</span> <span>        {
</span><span>126</span>             <span>throw</span> <span>new</span><span> Exception(ex.Message);
</span><span>127</span> <span>        }
</span><span>128</span>         <span>finally</span>
<span>129</span> <span>        {
</span><span>130</span>             <span>if</span> (m_Recordset != <span>null</span><span>)
</span><span>131</span> <span>            {
</span><span>132</span> <span>                m_Recordset.Close();
</span><span>133</span> <span>                ((IDisposable)m_Recordset).Dispose();
</span><span>134</span>                 m_Recordset = <span>null</span><span>;
</span><span>135</span> <span>            }
</span><span>136</span> <span>        }
</span><span>137</span> <span>    }
</span><span>138</span> 
<span>139</span>     <span>///</span> <span><summary></summary></span>
<span>140</span>     <span>///</span><span> 更新表格数据
</span><span>141</span>     <span>///</span> <span></span>
<span>142</span>     <span>///</span> <span><param name="tableName"></span><span>表格名称</span><span></span>
<span>143</span>     <span>///</span> <span><param name="data"></span><span>数据</span><span></span>
<span>144</span>     <span>public</span> <span>void</span> UpdateTable(<span>string</span> tableName, List<dictionary>string, <span>string</span>>><span> data)
</span><span>145</span> <span>    {
</span><span>146</span>         <span>try</span>
<span>147</span> <span>        {
</span><span>148</span>             m_Recordset = m_Database.OpenRecordset(tableName, <span>1</span>);<span>//</span><span> 1=RecordsetTypeEnum.dbOpenTable</span>
<span>149</span> <span>            m_Recordset.MoveFirst();
</span><span>150</span>             <span>for</span> (<span>int</span> rowIndex = <span>0</span>; rowIndex )
<span>151</span> <span>            {
</span><span>152</span> <span>                m_Recordset.Edit();
</span><span>153</span>                 <span>foreach</span> (<span>string</span> fieldName <span>in</span><span> data[rowIndex].Keys)
</span><span>154</span> <span>                {
</span><span>155</span>                     m_Recordset.Fields[fieldName].Value =<span> data[rowIndex][fieldName];
</span><span>156</span> <span>                }
</span><span>157</span> <span>                m_Recordset.Update();
</span><span>158</span> <span>                m_Recordset.MoveNext();
</span><span>159</span> <span>            }
</span><span>160</span> <span>        }
</span><span>161</span>         <span>catch</span><span> (Exception ex)
</span><span>162</span> <span>        {
</span><span>163</span>             <span>throw</span> <span>new</span><span> Exception(ex.Message);
</span><span>164</span> <span>        }
</span><span>165</span>         <span>finally</span>
<span>166</span> <span>        {
</span><span>167</span>             <span>if</span> (m_Recordset != <span>null</span><span>)
</span><span>168</span> <span>            {
</span><span>169</span> <span>                m_Recordset.Close();
</span><span>170</span> <span>                ((IDisposable)m_Recordset).Dispose();
</span><span>171</span>                 m_Recordset = <span>null</span><span>;
</span><span>172</span> <span>            }
</span><span>173</span> <span>        }
</span><span>174</span> <span>    }
</span><span>175</span> 
<span>176</span>     <span>///</span> <span><summary></summary></span>
<span>177</span>     <span>///</span><span> 关闭
</span><span>178</span>     <span>///</span> <span></span>
<span>179</span>     <span>public</span> <span>void</span><span> Close()
</span><span>180</span> <span>    {
</span><span>181</span>         <span>if</span> (m_Database != <span>null</span><span>)
</span><span>182</span> <span>        {
</span><span>183</span> <span>            m_Database.Close();
</span><span>184</span> <span>            ((IDisposable)m_Database).Dispose();
</span><span>185</span>             m_Database = <span>null</span><span>;
</span><span>186</span> <span>        }
</span><span>187</span>         <span>if</span> (m_AccessApp != <span>null</span><span>)
</span><span>188</span> <span>        {
</span><span>189</span> <span>            m_AccessApp.CloseCurrentDatabase();
</span><span>190</span>             <span>//</span><span> m_AccessApp.Quit();</span><span>//</span><span> 导致最后会弹出Access主页面</span>
<span>191</span> <span>            ((IDisposable)m_AccessApp).Dispose();
</span><span>192</span>             m_AccessApp = <span>null</span><span>;
</span><span>193</span> <span>        }
</span><span>194</span> <span>        GC.Collect();
</span><span>195</span> <span>    }
</span><span>196</span> }</dictionary></dictionary></list></list></list>
View Code

 

通过dynamic构建的COM对象,在使用完成后都要手动关闭销毁,比如代码中的m_AccessApp, m_Database, m_Recordset三个对象,否则只是将m_AccessApp关闭清空释放掉,Access进程还是无法关闭,在程序关闭之前,始终都会有一个空白的无法关闭的Access界面;

在循环中处理dynamic和C#类型转换会降低程序执行效率,就比如像GetTableNames方法中循环遍历表名,都要花两三秒时间,所以尽量像object[] dataRow = recordSet.GetRows();直接获取其中的所有数据,然后再遍历处理,会极大提高执行效率;

要修改Access中的数据时,一定要先m_Recordset.Edit();才会允许你编辑其中的内容;

声明
本文内容由网友自发贡献,版权归原作者所有,本站不承担相应法律责任。如您发现有涉嫌抄袭侵权的内容,请联系admin@php.cn
MySQL的许可与其他数据库系统相比如何?MySQL的许可与其他数据库系统相比如何?Apr 25, 2025 am 12:26 AM

MySQL使用的是GPL许可证。1)GPL许可证允许自由使用、修改和分发MySQL,但修改后的分发需遵循GPL。2)商业许可证可避免公开修改,适合需要保密的商业应用。

您什么时候选择InnoDB而不是Myisam,反之亦然?您什么时候选择InnoDB而不是Myisam,反之亦然?Apr 25, 2025 am 12:22 AM

选择InnoDB而不是MyISAM的情况包括:1)需要事务支持,2)高并发环境,3)需要高数据一致性;反之,选择MyISAM的情况包括:1)主要是读操作,2)不需要事务支持。InnoDB适合需要高数据一致性和事务处理的应用,如电商平台,而MyISAM适合读密集型且无需事务的应用,如博客系统。

在MySQL中解释外键的目的。在MySQL中解释外键的目的。Apr 25, 2025 am 12:17 AM

在MySQL中,外键的作用是建立表与表之间的关系,确保数据的一致性和完整性。外键通过引用完整性检查和级联操作维护数据的有效性,使用时需注意性能优化和避免常见错误。

MySQL中有哪些不同类型的索引?MySQL中有哪些不同类型的索引?Apr 25, 2025 am 12:12 AM

MySQL中有四种主要的索引类型:B-Tree索引、哈希索引、全文索引和空间索引。1.B-Tree索引适用于范围查询、排序和分组,适合在employees表的name列上创建。2.哈希索引适用于等值查询,适合在MEMORY存储引擎的hash_table表的id列上创建。3.全文索引用于文本搜索,适合在articles表的content列上创建。4.空间索引用于地理空间查询,适合在locations表的geom列上创建。

您如何在MySQL中创建索引?您如何在MySQL中创建索引?Apr 25, 2025 am 12:06 AM

toCreateAnIndexinMysql,usethecReateIndexStatement.1)forasingLecolumn,使用“ createIndexIdx_lastNameEnemployees(lastName); 2)foracompositeIndex,使用“ createIndexIndexIndexIndexIndexDx_nameOmplayees(lastName,firstName,firstName);” 3)forauniqe instex,creationexexexexex,

MySQL与Sqlite有何不同?MySQL与Sqlite有何不同?Apr 24, 2025 am 12:12 AM

MySQL和SQLite的主要区别在于设计理念和使用场景:1.MySQL适用于大型应用和企业级解决方案,支持高性能和高并发;2.SQLite适合移动应用和桌面软件,轻量级且易于嵌入。

MySQL中的索引是什么?它们如何提高性能?MySQL中的索引是什么?它们如何提高性能?Apr 24, 2025 am 12:09 AM

MySQL中的索引是数据库表中一列或多列的有序结构,用于加速数据检索。1)索引通过减少扫描数据量提升查询速度。2)B-Tree索引利用平衡树结构,适合范围查询和排序。3)创建索引使用CREATEINDEX语句,如CREATEINDEXidx_customer_idONorders(customer_id)。4)复合索引可优化多列查询,如CREATEINDEXidx_customer_orderONorders(customer_id,order_date)。5)使用EXPLAIN分析查询计划,避

说明如何使用MySQL中的交易来确保数据一致性。说明如何使用MySQL中的交易来确保数据一致性。Apr 24, 2025 am 12:09 AM

在MySQL中使用事务可以确保数据一致性。1)通过STARTTRANSACTION开始事务,执行SQL操作后用COMMIT提交或ROLLBACK回滚。2)使用SAVEPOINT可以设置保存点,允许部分回滚。3)性能优化建议包括缩短事务时间、避免大规模查询和合理使用隔离级别。

See all articles

热AI工具

Undresser.AI Undress

Undresser.AI Undress

人工智能驱动的应用程序,用于创建逼真的裸体照片

AI Clothes Remover

AI Clothes Remover

用于从照片中去除衣服的在线人工智能工具。

Undress AI Tool

Undress AI Tool

免费脱衣服图片

Clothoff.io

Clothoff.io

AI脱衣机

Video Face Swap

Video Face Swap

使用我们完全免费的人工智能换脸工具轻松在任何视频中换脸!

热工具

适用于 Eclipse 的 SAP NetWeaver 服务器适配器

适用于 Eclipse 的 SAP NetWeaver 服务器适配器

将Eclipse与SAP NetWeaver应用服务器集成。

DVWA

DVWA

Damn Vulnerable Web App (DVWA) 是一个PHP/MySQL的Web应用程序,非常容易受到攻击。它的主要目标是成为安全专业人员在合法环境中测试自己的技能和工具的辅助工具,帮助Web开发人员更好地理解保护Web应用程序的过程,并帮助教师/学生在课堂环境中教授/学习Web应用程序安全。DVWA的目标是通过简单直接的界面练习一些最常见的Web漏洞,难度各不相同。请注意,该软件中

SublimeText3 Mac版

SublimeText3 Mac版

神级代码编辑软件(SublimeText3)

记事本++7.3.1

记事本++7.3.1

好用且免费的代码编辑器

VSCode Windows 64位 下载

VSCode Windows 64位 下载

微软推出的免费、功能强大的一款IDE编辑器