如何优化这种循环？
我试图制作这个GUi。
我编写自己的布局，因为现有的布局管理器不符合我的要求
它工作，但我尝试通过使用循环优化所有按钮的创建。
的Test.class
public class Test {
public static void main(String[] args) {
JFrame f = new JFrame();
JPanel parent = new JPanel();
f.add(parent);
parent.setLayout(new BoxLayout(parent, BoxLayout.X_AXIS));
JPanel[] children = new JPanel[6];
for (int i = 1; i < children.length; i++) {
children[i] = new JPanel();
children[i].setLayout(new XYLayout());
children[i].setBorder(new LineBorder(Color.red));
parent.add(children[i]);
}
int x = 0, y = 375, w = 0, h = 50;
children[1].add(new JButton("8"), new XYConstraints(0, 25, 0, 50));
children[1].add(new JButton("7"), new XYConstraints(0, 75, 0, 50));
children[1].add(new JButton("6"), new XYConstraints(0, 125, 0, 50));
children[1].add(new JButton("5"), new XYConstraints(0, 175, 0, 50));
children[1].add(new JButton("4"), new XYConstraints(0, 225, 0, 50));
children[1].add(new JButton("3"), new XYConstraints(0, 275, 0, 50));
children[1].add(new JButton("2"), new XYConstraints(0, 325, 0, 50));
children[1].add(new JButton("1"), new XYConstraints(0, 375, 0, 50));
children[2].add(new JButton("7"), new XYConstraints(240, 25, 0, 100));
children[2].add(new JButton("6"), new XYConstraints(200, 75, 0, 100));
children[2].add(new JButton("5"), new XYConstraints(160, 125, 0, 100));
children[2].add(new JButton("4"), new XYConstraints(120, 175, 0, 100));
children[2].add(new JButton("3"), new XYConstraints(80, 225, 0, 100));
children[2].add(new JButton("2"), new XYConstraints(40, 275, 0, 100));
children[2].add(new JButton("1"), new XYConstraints(0, 325, 0, 100));
children[3].add(new JButton("6"), new XYConstraints(200, 25, 0, 150));
children[3].add(new JButton("5"), new XYConstraints(160, 75, 0, 150));
children[3].add(new JButton("4"), new XYConstraints(120, 125, 0, 150));
children[3].add(new JButton("3"), new XYConstraints(80, 175, 0, 150));
children[3].add(new JButton("2"), new XYConstraints(40, 225, 0, 150));
children[3].add(new JButton("1"), new XYConstraints(0, 275, 0, 150));
//children[4],//children[5]...
f.setSize(800, 600);
f.setLocationRelativeTo(null);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setVisible(true);
}
一个文件中的自定义布局：XYLayout
public class XYLayout implements LayoutManager2, Serializable {
private int width;
private int height;
Hashtable<Component, Object> info;
static final XYConstraints defaultConstraints = new XYConstraints();
public XYLayout() {
info = new Hashtable<Component, Object>();
}
public XYLayout(int width, int height) {
info = new Hashtable<Component, Object>();
this.width = width;
this.height = height;
}
public int getWidth() {
return width;
}
public void setWidth(int width) {
this.width = width;
}
public int getHeight() {
return height;
}
public void setHeight(int height) {
this.height = height;
}
/*
* (non-Javadoc)
*
* @see java.lang.Object#toString()
*/
@Override
public String toString() {
StringBuilder builder = new StringBuilder();
builder.append("XYLayout [width=").append(width).append(", height=").append(height).append("]");
return builder.toString();
}
public void addLayoutComponent(String s, Component component1) {
}
public void removeLayoutComponent(Component component) {
info.remove(component);
}
public Dimension preferredLayoutSize(Container target) {
return getLayoutSize(target, true);
}
public Dimension minimumLayoutSize(Container target) {
return getLayoutSize(target, false);
}
public void layoutContainer(Container target) {
Insets insets = target.getInsets();
int count = target.getComponentCount();
for (int i = 0; i < count; i++) {
Component component = target.getComponent(i);
if (component.isVisible()) {
Rectangle r = getComponentBounds(component, true);
component.setBounds(insets.left + r.x, insets.top + r.y, r.width, r.height);
}
}
}
public void addLayoutComponent(Component component, Object constraints) {
if (constraints instanceof XYConstraints)
info.put(component, constraints);
}
public Dimension maximumLayoutSize(Container target) {
return new Dimension(0x7fffffff, 0x7fffffff);
}
public float getLayoutAlignmentX(Container target) {
return 0.5F;
}
public float getLayoutAlignmentY(Container target) {
return 0.5F;
}
public void invalidateLayout(Container container) {
}
public Rectangle getComponentBounds(Component component, boolean doPreferred) {
XYConstraints constraints = (XYConstraints) info.get(component);
if (constraints == null)
constraints = defaultConstraints;
Rectangle r = new Rectangle(constraints.getX(), constraints.getY(), constraints.getW(), constraints.getH());
if (r.width <= 0 || r.height <= 0) {
Dimension d = doPreferred ? component.getPreferredSize() : component.getMinimumSize();
if (r.width <= 0)
r.width = d.width;
if (r.height <= 0)
r.height = d.height;
}
return r;
}
public Dimension getLayoutSize(Container target, boolean doPreferred) {
Dimension dim = new Dimension(0, 0);
if (width <= 0 || height <= 0) {
int count = target.getComponentCount();
for (int i = 0; i < count; i++) {
Component component = target.getComponent(i);
if (component.isVisible()) {
Rectangle r = getComponentBounds(component, doPreferred);
dim.width = Math.max(dim.width, r.x + r.width);
dim.height = Math.max(dim.height, r.y + r.height);
}
}
}
if (width > 0)
dim.width = width;
if (height > 0)
dim.height = height;
Insets insets = target.getInsets();
dim.width += insets.left + insets.right;
dim.height += insets.top + insets.bottom;
return dim;
}
}
class XYConstraints implements Cloneable, Serializable {
private int x;
private int y;
private int w;
private int h;
public XYConstraints() {
this(0, 0, 0, 0);
}
public XYConstraints(int x, int y, int w, int h) {
this.x = x;
this.y = y;
this.w = w;
this.h = h;
}
public int getX() {
return x;
}
public void setX(int x) {
this.x = x;
}
public int getY() {
return y;
}
public void setY(int y) {
this.y = y;
}
public int getW() {
return w;
}
public void setW(int w) {
this.w = w;
}
public int getH() {
return h;
}
public void setH(int h) {
this.h = h;
}
/*
* (non-Javadoc)
*
* @see java.lang.Object#hashCode()
*/
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + h;
result = prime * result + w;
result = prime * result + x;
result = prime * result + y;
return result;
// return x ^ y * 37 ^ w * 43 ^ h * 47;
}
public boolean equals(Object that) {
if (that instanceof XYConstraints) {
XYConstraints other = (XYConstraints) that;
return other.x == x && other.y == y && other.w == w && other.h == h;
} else {
return false;
}
}
public Object clone() {
return new XYConstraints(x, y, w, h);
}
/*
* (non-Javadoc)
*
* @see java.lang.Object#toString()
*/
@Override
public String toString() {
StringBuilder builder = new StringBuilder();
builder.append("XYConstraints [x=").append(x).append(", y=").append(y).append(", w=").append(w).append(", h=").append(h).append("]");
return builder.toString();
}
我的第一次尝试是：
for (y = 375; y > 0; y = y - 50)
children[1].add(new JButton("1"), new XYConstraints(x, y, w, h));
for (y = 325, x = 0; y > 0 && x < 280; y = y - 50, x = x + 40)
children[2].add(new JButton("2"), new XYConstraints(x, y, w, 2 * h));
for (y = 275, x = 0; y > 0 && x < 240; y = y - 50, x = x + 40)
children[3].add(new JButton("3"), new XYConstraints(x, y, w, 3 * h));
但有些东西像孩子[i]＆＃34;的循环一样失踪。我确定有更好的解决方案来改善循环任何改进或建议的想法？感谢
2 个答案:
答案 0 :(得分：3)
我编写自己的布局，因为现有的布局管理器不符合我的要求
正确的想法，但您的实施不正确。您需要提供x / y值这一事实意味着您不使用布局管理器，而只是硬编码某些值。
相反，您需要向布局管理器提供信息以定义布局的参数，可能类似于：
MyLayout layout = new MyLayout(xSize, ySize, xOffset, yOffset);
因此，对于您将使用的第一个面板：
MyLayout layout = new MyLayout(50, 50, 0, 50);
这段代码会说每个组件都是（50,50）。在向面板添加组件时，将x偏移更改为0，y offset = -50。
你知道你有8个按钮，所以你可以用数学来计算面板的宽度/高度。然后，您可以在布局管理器中使用循环来定位每个组件。
现在，您可以向面板添加组件，如：
panel.add( new JButton("1") );
panel.add( new JButton("2") );
panel.add( new JButton("3") );
对于第二个面板，您可以使用：
MyLayout layout = new MyLayout(50, 100, 50, 50);
所以这一次意味着每个按钮的大小都是（50,100），每个按钮都放在（50，-50）前一个按钮上。
这就是应该如何创建布局管理器。您不应该需要复杂的循环来构建添加到面板的每个组件的约束。这是布局管理员的工作。
答案 1 :(得分：1)
你可以尝试：
for( int i=1; i<=3; i++ ) {
x = 0;
for( y=375-((i-1)*50; y>0; y-=50, x+=40 ) {
children[i].add(new JButton((String)i), new XYConstraints(x, y, w, i*h));
}
}
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