在面板中居中字符串

问题描述

目前我正在做这件事：

pre> public void paintComponent（Graphics g）{
super.paintComponent（g）;
int stringWidth = 0;
int stringAccent = 0;
int xCoordinate = 0;
int yCoordinate = 0;
//获取当前字体的FontMetrics
FontMetrics fm = g.getFontMetrics（）;

$ b / **显示新消息* /
if（currentMessage.equals（message1））{
removeAll（）;
/ **居中文本* /
//找到显示的中心位置
stringWidth = fm.stringWidth（message2）;
stringAccent = fm.getAscent（）;
//获取基线中最左边字符的位置
xCoordinate = getWidth（）/ 2 - stringWidth / 2;
yCoordinate = getHeight（）/ 2 + stringAccent / 2;

//绘制字符串
g.drawString（message2，xCoordinate，yCoordinate）;
currentMessage = message2; // alternate message
}
}


有没有一种方法可以用来简化这个任务？

例如：

  public void paintComponent（Graphics g）{
 super.paintComponent（g）; 
 if（currentMessage.equals（message1））{
 removeAll（）; 
 //绘制字符串居中（用一行代码）
} 
} 
  

看来我只是为了中心​​文本而做了很多工作。

在java标准中图书馆？不，你可以随时做这些事情。

  private void drawStringMiddleOfPanel（String string，Graphics g）{
 String message2 = string; 
 int stringWidth = 0; 
 int stringAccent = 0; 
 int xCoordinate = 0; 
 int yCoordinate = 0; 
 //获取当前字体的FontMetrics 
 FontMetrics fm = g.getFontMetrics（）; 
 
 
 / **显示新消息* / 
 / **居中文本* / 
 //找到要显示的中心位置
 stringWidth = fm.stringWidth（消息2）; 
 stringAccent = fm.getAscent（）; 
 //获取基线中最左边字符的位置
 xCoordinate = getWidth（）/ 2  -  stringWidth / 2; 
 yCoordinate = getHeight（）/ 2 + stringAccent / 2; 
 
 //绘制字符串
 g.drawString（message2，xCoordinate，yCoordinate）; 
 currentMessage = message2; //备用信息
} 
  

使用

  public void paintComponent（Graphics g）{
 super.paintComponent（g）; 
 if（currentMessage.equals（message1））{
 removeAll（）; 
 drawStringMiddleOfPanel（message1，g）; 
} 
} 
  

I'm trying to center a String in a Panel.

Currently I'm doing this:

public void paintComponent(Graphics g) {
        super.paintComponent(g);
            int stringWidth = 0;
            int stringAccent = 0;
            int xCoordinate = 0;
            int yCoordinate = 0;
            // get the FontMetrics for the current font
            FontMetrics fm = g.getFontMetrics();


        /** display new message */
        if (currentMessage.equals(message1)) {
            removeAll();
            /** Centering the text */
            // find the center location to display
            stringWidth = fm.stringWidth(message2);
            stringAccent = fm.getAscent();
            // get the position of the leftmost character in the baseline
            xCoordinate = getWidth() / 2 - stringWidth / 2;
            yCoordinate = getHeight() / 2 + stringAccent / 2;

            // draw String
            g.drawString(message2, xCoordinate, yCoordinate);
            currentMessage = message2;  // alternate message
        }
}

Is there a single method I can use to simplify this task?

For example:

public void paintComponent(Graphics g) {
            super.paintComponent(g);
            if (currentMessage.equals(message1)) {
                removeAll();
                // draw String centered (with one line of code)
            }
}

Just seems like I'm doing a lot of work just to center text.

解决方案

In the java standard library? No, you can always do something along this

private void drawStringMiddleOfPanel(String string, Graphics g) {
            String message2 = string;
            int stringWidth = 0;
            int stringAccent = 0;
            int xCoordinate = 0;
            int yCoordinate = 0;
            // get the FontMetrics for the current font
            FontMetrics fm = g.getFontMetrics();


        /** display new message */
            /** Centering the text */
            // find the center location to display
            stringWidth = fm.stringWidth(message2);
            stringAccent = fm.getAscent();
            // get the position of the leftmost character in the baseline
            xCoordinate = getWidth() / 2 - stringWidth / 2;
            yCoordinate = getHeight() / 2 + stringAccent / 2;

            // draw String
            g.drawString(message2, xCoordinate, yCoordinate);
            currentMessage = message2;  // alternate message
        }

With

public void paintComponent(Graphics g) {
        super.paintComponent(g);
        if (currentMessage.equals(message1)) {
            removeAll();
            drawStringMiddleOfPanel(message1, g);
        }
 }

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