ScrollableControl::AutoScrollPosition Property
Gets or sets the location of the auto-scroll position.
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)
The AutoScrollPosition property represents the location of the visible portion of a scrollable control. Use this property to change the portion of the control that is displayed.
When adding controls programmatically to a form, use the AutoScrollPosition property to position the control either inside or outside of the current viewable scroll area.
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The X and Y coordinate values retrieved are negative if the control has scrolled away from its starting position (0,0). When you set this property, you must always assign positive X and Y values to set the scroll position relative to the starting position. For example, if you have a horizontal scroll bar and you set x and y to 200, you move the scroll 200 pixels to the right; if you then set x and y to 100, the scroll appears to jump the left by 100 pixels, because you are setting it 100 pixels away from the starting position. In the first case, AutoScrollPosition returns {-200, 0}; in the second case, it returns {-100,0}. |
To detect when AutoScrollPosition changes, create an event handler for the Paint event, save the old position value in a private variable, and compare the new value to the old value on subsequent Paint events.
The following code example uses the ScrollableControl derived class Panel and adds a button to the upper left corner of the scrollable area. The example allows for the offset determined by the AutoScrollPosition. The example was written under the assumption that you have a Form that contains a Panel with a Button on it. To enable auto-scrolling, place the button outside of the client area of the Panel.
private: void button1_Click( Object^ /*sender*/, EventArgs^ /*e*/ ) { /* Add a button to top left corner of the * scrollable area, allowing for the offset. */ panel1->AutoScroll = true; Button^ myButton = gcnew Button; myButton->Location = Point(0 + panel1->AutoScrollPosition.X,0 + panel1->AutoScrollPosition.Y); panel1->Controls->Add( myButton ); }
Available since 1.1
