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我想從表中創建一個緩衝圖像，當我將表添加到應用程序框架，並設置大小，我能夠正確地查看它，但是當我將它轉換爲圖像我只能看到表格的第一行，其餘的表格沒有標題。jtable圖像轉換不能正常發生
的代碼生成表是
table = new JTable();
String[] table_header = null;
TextAreaRenderer textAreaRenderer = new TextAreaRenderer();
table_model = new DefaultTableModel() {
@Override
public boolean isCellEditable(int row, int column) {
return false;
}
};
table.setModel(table_model);
table.setSize(300, 700);
JScrollPane pane = new JScrollPane(table);
createTableDataSet(input1, input2, varient, headertype);
TableColumnModel cmodel = table.getColumnModel();
table_header = obtainTableHeader(headertype);
for (int i = 0; i < table_header.length; i++) {
cmodel.getColumn(i).setCellRenderer(textAreaRenderer);
}
return table;
以生成所述圖像的代碼：
JTableHeader header =table.getTableHeader();
int w = Math.max(table.getWidth(), header.getWidth());
int h = table.getHeight() + header.getHeight();
BufferedImage bi = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
Graphics2D g2 = bi.createGraphics();
header.paint(g2);
g2.translate(0, header.getHeight());
table.paint(g2);
g2.dispose();
try {
ImageIO.write(bi, "png", new File("year.png"));
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
表中的圖像是
更新1：我可能已經發現問題的原因。我正在使用下面的代碼片段爲了增加單元格的大小，以便文本被包裝到單元格中。包括引起問題的代碼 private finalTargetCellRenderer renderer = new DefaultTableCellRenderer（）;
// Column heights are placed in this Map
private final Map<JTable, Map<Object, Map<Object, Integer>>> tablecellSizes = new HashMap<JTable, Map<Object, Map<Object, Integer>>>();
/**
* Creates a text area renderer.
*/
public TextAreaRenderer() {
setLineWrap(true);
setWrapStyleWord(true);
}
/**
* Returns the component used for drawing the cell. This method is
* used to configure the renderer appropriately before drawing.
*
* @param table - JTable object
* @param value - the value of the cell to be rendered.
* @param isSelected - isSelected true if the cell is to be rendered with the selection highlighted;
* otherwise false.
* @param hasFocus - if true, render cell appropriately.
* @param row - The row index of the cell being drawn.
* @param column - The column index of the cell being drawn.
* @return - Returns the component used for drawing the cell.
*/
public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected,
boolean hasFocus, int row, int column) {
// set the Font, Color, etc.
renderer.getTableCellRendererComponent(table, value,
isSelected, hasFocus, row, column);
setForeground(renderer.getForeground());
setBackground(renderer.getBackground());
setBorder(renderer.getBorder());
setFont(renderer.getFont());
setText(renderer.getText());
TableColumnModel columnModel = table.getColumnModel();
setSize(columnModel.getColumn(column).getWidth(), 0);
int height_wanted = (int) getPreferredSize().getHeight();
addSize(table, row, column, height_wanted);
height_wanted = findTotalMaximumRowSize(table, row);
if (height_wanted != table.getRowHeight(row)) {
table.setRowHeight(row, height_wanted);
}
return this;
}
/**
* @param table - JTable object
* @param row - The row index of the cell being drawn.
* @param column - The column index of the cell being drawn.
* @param height - Row cell height as int value
* This method will add size to cell based on row and column number
*/
private void addSize(JTable table, int row, int column, int height) {
Map<Object, Map<Object, Integer>> rowsMap = tablecellSizes.get(table);
if (rowsMap == null) {
tablecellSizes.put(table, rowsMap = new HashMap<Object, Map<Object, Integer>>());
}
Map<Object, Integer> rowheightsMap = rowsMap.get(row);
if (rowheightsMap == null) {
rowsMap.put(row, rowheightsMap = new HashMap<Object, Integer>());
}
rowheightsMap.put(column, height);
}
/**
* Look through all columns and get the renderer. If it is
* also a TextAreaRenderer, we look at the maximum height in
* its hash table for this row.
*
* @param table -JTable object
* @param row - The row index of the cell being drawn.
* @return row maximum height as integer value
*/
private int findTotalMaximumRowSize(JTable table, int row) {
int maximum_height = 0;
Enumeration<TableColumn> columns = table.getColumnModel().getColumns();
while (columns.hasMoreElements()) {
TableColumn tc = columns.nextElement();
TableCellRenderer cellRenderer = tc.getCellRenderer();
if (cellRenderer instanceof TextAreaRenderer) {
TextAreaRenderer tar = (TextAreaRenderer) cellRenderer;
maximum_height = Math.max(maximum_height,
tar.findMaximumRowSize(table, row));
}
}
return maximum_height;
}
/**
* This will find the maximum row size
*
* @param table - JTable object
* @param row - The row index of the cell being drawn.
* @return row maximum height as integer value
*/
private int findMaximumRowSize(JTable table, int row) {
Map<Object, Map<Object, Integer>> rows = tablecellSizes.get(table);
if (rows == null) return 0;
Map<Object, Integer> rowheights = rows.get(row);
if (rowheights == null) return 0;
int maximum_height = 0;
for (Map.Entry<Object, Integer> entry : rowheights.entrySet()) {
int cellHeight = entry.getValue();
maximum_height = Math.max(maximum_height, cellHeight);
}
return maximum_height;
}
這導致單元格不能正確顯示。一旦我刪除了這個代碼，表格就是通過包含kleopatra的代碼正確生成的。但我堅持在單元格中換行的問題。
感謝， 巴維亞
附：當我的代碼中使用新的JTable（行，字段）創建表對象時，我已經使用上述相同的代碼生成圖像，並讀取序列化的散列表並將其插入到table_model中
怎麼樣table.getPreferredSize（）。height？它返回什麼？ – SteeveDroz
@Oltarus對不起，我意識到這是因爲我將表添加到應用程序框架，如果我嘗試直接創建圖像我得到一個表的高度的值，但標題和數據不正確可見tha表 – bhavs
我看到header.getHeight返回0，我將這個頭添加到table_model並將table_model添加到tabel。有沒有解決這個問題的方法？ – bhavs