Provides access to members that control the reading and writing of map document files.(提供访问的成员,控制读写地图文档文件)
1：MapDocumentClass Class
The MapDocument coclass is used to read and write map document files.(地图文档组件类是用于读写地图文档文件。)实现了IMapDocument接口。
m_MapDocument = new MapDocumentClass();
2：Open Method
[C#]public void Open (string sDocument,string bsPassword);
[C++]HRESULT Open( BSTR sDocument, BSTR bsPassword);
The MapDocument will be cached so no other users will be able to access the MapDocument until it has been closed.(MapDocument将会被缓存，所以没有其他用户可以访问MapDocument,除非它已被关闭。)Before using the Open methods check whether the specified document IsPresent, IsRestricted, IsMapDocument and IsPasswordProtected. If the MapDocument is password protected, specify the password in the Open method.
3：MapCount Property
The number of Map objects contained within the map document
// 使用IMapDocument打开文档
IMapDocument m_MapDocument;
private void LoadMapDoc()
{
m_MapDocument = new MapDocumentClass();
try
{
//打开文档对话框选择MXD文件
System.Windows.Forms. OpenFileDialog openFileDialog2;
openFileDialog2 = new OpenFileDialog();
openFileDialog2.Title = "Open Map Document";
openFileDialog2.Filter = "Map Documents (*.mxd)|*.mxd";
openFileDialog2.ShowDialog();
string sFilePath = openFileDialog2.FileName;
//将数据加载到pMapDocument并与MapControl联系起来
m_MapDocument.Open(sFilePath, "");
int i;
int sum = m_MapDocument.MapCount ;
for (i = 0; i <sum; i++)
{
// 一个IMapDocument对象中可能包含很多Map对象，遍历map对象
axMapControl1.Map = m_MapDocument.get_Map(i);
}
// 刷新地图控件
axMapControl1.Refresh();
}
catch ( Exception ex)
{
MessageBox.Show(ex.ToString());
}
}
4：Map Property
[C#]public IMap get_Map (int mapIndex);
[C++]HRESULT get_Map(long mapIndex, IMap** ppMap);
5：IsReadOnly Property
[C#]public bool get_IsReadOnly (string sDocument);
[C++]HRESULT get_IsReadOnly( BSTR sDocument, VARIANT_BOOL* IsReadOnly);
Determines whether the specified file is read only. The Save method cannot overwrite a read-only MapDocument, use the SaveAs to write to a new document.（保存方法不能覆盖只读的地图文件，使用另存为）
6：Save Method
[C#]public void Save (bool bUseRelativePaths, bool bCreateThumnbail);
[C#]Optional Values
bUseRelativePaths Supply true as a default value.(true代码默认值)
bCreateThumnbail Supply true as a default value.
[C++]HRESULT Save(VARIANT_BOOL bUseRelativePaths,VARIANT_BOOL bCreateThumnbail);
7:UsesRelativePaths Property
[C#]public boolUsesRelativePaths {get;}
[C++]HRESULT get_UsesRelativePaths(VARIANT_BOOL* bUsesRelativePaths);文件是
Indicates if the data in the map document is referenced using relative paths.
（表明如果数据在地图文件是使用相对路径引用。）
// 使用IMapDocument保存文档
private void SaveDocument()
{
// 判断文档是否为只读
if (m_MapDocument.get_IsReadOnly(m_MapDocument.DocumentFilename))
{
MessageBox.Show( "This map document is read only!");
return;
}
//用当前的文件路径设置保存文件
m_MapDocument.Save(m_MapDocument.UsesRelativePaths, true);
MessageBox.Show( "Changes saved successfully!");
}
8：SaveAs Method
Save the contents of the map document to the specified file name.
[C#]public void SaveAs (string sDocument, bool bUseRelativePaths, boolbCreateThumnbail);
Optional Values
bUseRelativePaths Supply true as a default value.
bCreateThumnbail Supply true as a default value.
// 地图文档另存为
private void SaveAsDocument ()
{
//Open a file dialog for saving map documents
SaveFileDialog saveFileDialog1 = new SaveFileDialog();
saveFileDialog1.Title = "Save Map Document As";
saveFileDialog1.Filter = "Map Documents (*.mxd)|*.mxd";
saveFileDialog1.ShowDialog();
//Exit if no map document is selected
string sFilePath = saveFileDialog1.FileName;
if (sFilePath == "")
{
return;
}
if (sFilePath == m_MapDocument.DocumentFilename)
{
// 当选择文件和当前文件相同时，保存即可
SaveDocument();
}
else
{
//SaveAs a new document with relative paths
m_MapDocument.SaveAs(sFilePath, true, true);
//Open document
MessageBox.Show( "Document saved successfully!");
}
}
IMapDocument interface