Question

SWT中shell窗口中有一个按钮和一个canvas控件，怎样保证在点击按钮后，还可以让键盘监听保持在canvas上

SWT中shell窗口中有一个按钮和一个canvas控件，怎样保证在点击按钮后，还可以让键盘监听保持在canvas上，即在点击按钮后，还可通过键盘控制canvas上的动作，而不用点击一下canvas？
请高手指点

Answer 1

我写了个测试代码，你看看吧。希望会有帮助

public class FocusTest {
/**
* @param args
*/
public static void main(String[] args) {

Display display = Display.getDefault();
Shell shell = new Shell(display);
shell.setText("canvas测试");
shell.setSize(300, 400);

final Canvas canvas = new Canvas(shell, SWT.BORDER);

canvas.setBounds(100, 100, 100, 50);

final Button button = new Button(shell, SWT.NONE);
button.setFocus();
button.setText("聚焦到Canvas");
button.setBounds(100, 160, 100, 20);
button.addSelectionListener(new SelectionListener() {
public void widgetDefaultSelected(SelectionEvent e) {
}

public void widgetSelected(SelectionEvent e) {
canvas.setFocus();
button.setText("请按下任意键");
}

});

canvas.addKeyListener(new KeyListener() {

public void keyPressed(KeyEvent e) {
Canvas can = (Canvas) e.getSource();
can.setBackground(Display.getCurrent().getSystemColor(
SWT.COLOR_BLUE));
}

public void keyReleased(KeyEvent e) {

}

});
shell.open();

shell.layout();

while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}

}

}

Answer 2

用xlib做个窗口通过printf("b2\n");
wm_hints->flags |= InputHint;
printf("b3\n");
wm_hints->input = False;
printf("b4\n");
XSetWMHints(display, parent, wm_hints);
可以达到失去焦点效果。