添加元素时，如何将ScrolledComposite的滚动条移动到底部

Question

有一个ScrolledComposite，其中有一个添加更多按钮的按钮，其想法是在添加新项目时始终将垂直滚动条移动到底部。

如何做到这一点？这是向ScrolledComposite:添加按钮的示例代码

public boolean open() {     
shell = new Shell(getParent(), getStyle());
shell.setText(getText());

GridLayout gl_shell = new GridLayout(1, false);
gl_shell.marginWidth = 20;
shell.setLayout(gl_shell);

final ScrolledComposite sc1 = new ScrolledComposite(shell, SWT.H_SCROLL | SWT.V_SCROLL | SWT.BORDER);
final Composite c1 = new Composite(sc1, SWT.NONE);
sc1.setContent(c1);
final GridLayout layout = new GridLayout();
layout.numColumns = 1;
c1.setLayout(layout);
final Button b1 = new Button (c1, SWT.PUSH);
b1.setText("first button");
c1.setSize(200,200);
final Button add = new Button(shell, SWT.PUSH);
add.setText("add children");
final int[] index = new int[]{0};
add.addListener(SWT.Selection, new Listener() {
public void handleEvent(final Event e) {
index[0]++;
final Button button = new Button(c1, SWT.PUSH);
button.setText("button "+index[0]);
// reset size of content so children can be seen - method 1
c1.setSize(c1.computeSize(SWT.DEFAULT, SWT.DEFAULT));
c1.layout();
}
});


shell.layout();
shell.pack(); //for wrap the dialog size to it's content width and height.

//the dialog must be centered after doing shell.pack();
Rectangle parentSize = getParent().getBounds();
Rectangle shellSize = shell.getBounds();
int x = parentSize.x + (parentSize.width - shellSize.width) / 2;
int y = (int) (parentSize.y + (parentSize.height - shellSize.height) / 3.5);
shell.setLocation(new Point(x, y));
shell.open(); //we put this after setLocation() and pack() because we don't want to see the shell on the original position for some milliseconds

Display display = getParent().getDisplay();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}


return false;
}

Answer 1

ScrolledComposite具有

public void showControl(Control control)

方法，以确保控件可见。

还有

public void setShowFocusedControl(boolean show)

这确保始终显示具有焦点的控制(在内部使用showControl(。