我正在製作一個GUI,其中顯示了一個大的JPanel上方的三個JToolBar。這些工具欄總的來說非常大,所以我使用FlowLayout來使它們在到達JFrame邊界時換行到下一行。問題是,當他們換行到下一行時,它們被下面的JPanel隱藏起來..我希望我可以強制包含工具欄的JPanel足夠長,以顯示所有工具欄..如何讓JToolBar在下一行(FlowLayout)中不隱藏下面的JPanel?
有沒有辦法這個?或者有另一種方法可以使這些工具欄可見嗎?
我正在製作一個GUI,其中顯示了一個大的JPanel上方的三個JToolBar。這些工具欄總的來說非常大,所以我使用FlowLayout來使它們在到達JFrame邊界時換行到下一行。問題是,當他們換行到下一行時,它們被下面的JPanel隱藏起來..我希望我可以強制包含工具欄的JPanel足夠長,以顯示所有工具欄..如何讓JToolBar在下一行(FlowLayout)中不隱藏下面的JPanel?
有沒有辦法這個?或者有另一種方法可以使這些工具欄可見嗎?
我以前遇到過這個問題。我發現最好的解決方案是使用FlowLayout
的修改版本,該版本考慮垂直變化並將它們包裝到下一行。這是這種佈局的代碼。
import java.awt.*;
/**
* A modified version of FlowLayout that allows containers using this
* Layout to behave in a reasonable manner when placed inside a
* JScrollPane
* @author Babu Kalakrishnan
* Modifications by greearb and jzd
*/
public class ModifiedFlowLayout extends FlowLayout {
public ModifiedFlowLayout() {
super();
}
public ModifiedFlowLayout(int align) {
super(align);
}
public ModifiedFlowLayout(int align, int hgap, int vgap) {
super(align, hgap, vgap);
}
public Dimension minimumLayoutSize(Container target) {
// Size of largest component, so we can resize it in
// either direction with something like a split-pane.
return computeMinSize(target);
}
public Dimension preferredLayoutSize(Container target) {
return computeSize(target);
}
private Dimension computeSize(Container target) {
synchronized (target.getTreeLock()) {
int hgap = getHgap();
int vgap = getVgap();
int w = target.getWidth();
// Let this behave like a regular FlowLayout (single row)
// if the container hasn't been assigned any size yet
if (w == 0) {
w = Integer.MAX_VALUE;
}
Insets insets = target.getInsets();
if (insets == null){
insets = new Insets(0, 0, 0, 0);
}
int reqdWidth = 0;
int maxwidth = w - (insets.left + insets.right + hgap * 2);
int n = target.getComponentCount();
int x = 0;
int y = insets.top + vgap; // FlowLayout starts by adding vgap, so do that here too.
int rowHeight = 0;
for (int i = 0; i < n; i++) {
Component c = target.getComponent(i);
if (c.isVisible()) {
Dimension d = c.getPreferredSize();
if ((x == 0) || ((x + d.width) <= maxwidth)) {
// fits in current row.
if (x > 0) {
x += hgap;
}
x += d.width;
rowHeight = Math.max(rowHeight, d.height);
}
else {
// Start of new row
x = d.width;
y += vgap + rowHeight;
rowHeight = d.height;
}
reqdWidth = Math.max(reqdWidth, x);
}
}
y += rowHeight;
y += insets.bottom;
return new Dimension(reqdWidth+insets.left+insets.right, y);
}
}
private Dimension computeMinSize(Container target) {
synchronized (target.getTreeLock()) {
int minx = Integer.MAX_VALUE;
int miny = Integer.MIN_VALUE;
boolean found_one = false;
int n = target.getComponentCount();
for (int i = 0; i < n; i++) {
Component c = target.getComponent(i);
if (c.isVisible()) {
found_one = true;
Dimension d = c.getPreferredSize();
minx = Math.min(minx, d.width);
miny = Math.min(miny, d.height);
}
}
if (found_one) {
return new Dimension(minx, miny);
}
return new Dimension(0, 0);
}
}
}
看看WrapLayout。它爲我工作。代碼是Here。
什麼是'synchronized(target.getTreeLock())'用於? – 2011-06-13 19:16:57
@Jason保持計算線程安全。但是,我不知道是否有必要。我對此的修改從不處理同步。 – jzd 2011-06-13 19:21:28
謝謝你!這爲我節省了很多時間,乾淨的解決方案也是 – 2011-12-02 08:56:02