ArcGIS enginee C#编写代码在axMapControl中打开一个要素类文件，生成一些不在该要素类范围内的均匀分布的随机点，并绘制在axMapControl上

以下是在 `axMapControl` 控件中打开要素类文件，生成随机点并绘制的 C# 代码示例：

// Instantiate a new MapControl object
AxMapControl mapControl = new AxMapControl();

// Set the workspace path where the feature class is located
string workspacePath = @"C:\Data\MyGeodatabase.gdb";

// Set the name of the feature class to open
string featureClassName = "MyFeatureClass";

// Open the feature class
IFeatureClass featureClass = OpenFeatureClass(workspacePath, featureClassName);

// Generate random points
IPoint[] randomPoints = GenerateRandomPoints(featureClass, 100);

// Add the random points to a new feature class
IFeatureClass randomPointsFeatureClass = AddRandomPointsToFeatureClass(workspacePath, "RandomPoints", randomPoints);

// Add the random points feature class to the map
AddFeatureClassToMap(mapControl, randomPointsFeatureClass);

// Refresh the map control
mapControl.Refresh();

在上面的代码中，`OpenFeatureClass` 方法会打开指定的要素类，`GenerateRandomPoints` 方法会生成指定数量的随机点，`AddRandomPointsToFeatureClass` 方法会将随机点添加到一个新的要素类中，`AddFeatureClassToMap` 方法会将新的要素类添加到 `axMapControl` 控件中。在执行完所有操作之后，最后通过调用 `Refresh` 方法来刷新 `axMapControl` 控件。

下面是 `OpenFeatureClass` 方法的代码示例：

public static IFeatureClass OpenFeatureClass(string workspacePath, string featureClassName)
{
    // Instantiate a new workspace factory
    IWorkspaceFactory workspaceFactory = new FileGDBWorkspaceFactory();

    // Open the workspace
    IWorkspace workspace = workspaceFactory.OpenFromFile(workspacePath, 0);

    // Open the feature class
    IFeatureWorkspace featureWorkspace = workspace as IFeatureWorkspace;
    IFeatureClass featureClass = featureWorkspace.OpenFeatureClass(featureClassName);

    return featureClass;
}

下面是 `GenerateRandomPoints` 方法的代码示例：

public static IPoint[] GenerateRandomPoints(IFeatureClass featureClass, int numPoints)
{
    // Get the extent of the feature class
    IEnvelope envelope = featureClass.Extent;

    // Generate random points within the extent
    IRandom random = new RandomNumberGeneratorClass();
    IPoint[] randomPoints = new IPoint[numPoints];
    for (int i = 0; i < numPoints; i++)
    {
        double x = envelope.XMin + (envelope.XMax - envelope.XMin) * random.NextDouble();
        double y = envelope.YMin + (envelope.YMax - envelope.YMin) * random.NextDouble();
        IPoint point = new PointClass();
        point.PutCoords(x, y);
        randomPoints[i] = point;
    }

    return randomPoints;
}

下面是 `AddRandomPointsToFeatureClass` 方法的代码示例：

public static IFeatureClass AddRandomPointsToFeatureClass(string workspacePath, string featureClassName, IPoint[] points)
{
    // Instantiate a new workspace factory
    IWorkspaceFactory workspaceFactory = new FileGDBWorkspaceFactory();

    // Open the workspace
    IWorkspace workspace = workspaceFactory.OpenFromFile(workspacePath, 0);

    // Create a new feature class
    IFeatureWorkspace featureWorkspace = workspace as IFeatureWorkspace;
    IFields fields = new FieldsClass();
    IFieldsEdit fieldsEdit = fields as IFieldsEdit;
    IField objectIDField = new FieldClass();
    IFieldEdit objectIDFieldEdit = objectIDField as IFieldEdit;
    objectIDFieldEdit.Name_2 = "OBJECTID";
    objectIDFieldEdit.Type_2 = esriFieldType.esriFieldTypeOID;
    fieldsEdit.AddField(objectIDField);
    IField shapeField = new FieldClass();
    IFieldEdit shapeFieldEdit = shapeField as IFieldEdit;
    shapeFieldEdit.Name_2 = "SHAPE";
    shapeFieldEdit.Type_2 = esriFieldType.esriFieldTypeGeometry;
    IGeometryDef geometryDef = new GeometryDefClass();
    IGeometryDefEdit geometryDefEdit = geometryDef as IGeometryDefEdit;
    geometryDefEdit.GeometryType_2 = esriGeometryType.esriGeometryPoint;
    geometryDefEdit.SpatialReference_2 = ((IGeoDataset)featureClass).SpatialReference;
    shapeFieldEdit.GeometryDef_2 = geometryDef;
    fieldsEdit.AddField(shapeField);
    IFeatureClass featureClass = featureWorkspace.CreateFeatureClass(featureClassName, fields, null, null, esriFeatureType.esriFTSimple, "SHAPE", "");
    
    // Add the random points to the feature class
    IFeatureBuffer featureBuffer = featureClass.CreateFeatureBuffer();
    IFeatureCursor featureCursor = featureClass.Insert(true);
    for (int i = 0; i < points.Length; i++)
    {
        featureBuffer.Shape = points[i];
        featureCursor.InsertFeature(featureBuffer);
    }
    featureCursor.Flush();

    return featureClass;
}

下面是 `AddFeatureClassToMap` 方法的代码示例：

public static void AddFeatureClassToMap(AxMapControl mapControl, IFeatureClass featureClass)
{
    // Create a new feature layer
    IFeatureLayer featureLayer = new FeatureLayerClass();
    featureLayer.FeatureClass = featureClass;
    featureLayer.Name = featureClass.AliasName;

    // Add the feature layer to the map
    mapControl.Map.AddLayer(featureLayer);
}

请注意，以上代码仅供参考，你可能需要根据自己的需求进行修改和调整。