conn.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + App.Path + "\MyDatas.mdb;Persist Security Info=False"

conn.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + App.Path + "\MyDatas.mdb;Persist Security Info=False"
conn.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + App.Path + "\MyDatas.mdb;Persist Security Info=False"

conn.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + App.Path + "\MyDatas.mdb;Persist Security Info=False"
"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + App.Path + "\MyDatas.mdb;Persist Security Info=False"
是将三个string字符串合并成一个字符串
然后赋值给ConnectionString

conn.connectionstring =“供应商=微软。射流为4；数据源。。=”+应用+“。路径\ mydatas。数据库；坚持安全信息=假”