swt 设为背景的图片为什么会消失

[yzg000123]

先把代码看下

if(enforc == true){
			image = new Image(display, compositeImage.getClientArea().width,
					compositeImage.getClientArea().height);
			image.type = SWT.BITMAP;
			r_gc = new GC(image);
			int min_x = table_min_x;
			int max_y = table_max_y;
			// 画图开始位置
			for (int i = 0; i < LIST_R_SIZE; i++) {
				r_coordinate_x = (file_r_x[i] - table_min_x) / drawpictureRate_x
						+ pictureBegin_x;
				r_coordinate_y = (drawpictureRate_y * picture_h - file_r_y[i] + table_max_y)
						/ drawpictureRate_y - (picture_h - pictureBegin_y);
				r_gc.setForeground(display.getSystemColor(SWT.COLOR_BLUE));
				r_gc.drawOval(r_coordinate_x, r_coordinate_y, diameter, diameter);
			}
			for (int i = 0; i < LIST_S_SIZE; i++) {
				s_coordinate_x = (file_s_x[i] - table_min_x) / drawpictureRate_x
						+ pictureBegin_x;
				s_coordinate_y = (drawpictureRate_y * picture_h - file_s_y[i] + table_max_y)
						/ drawpictureRate_y - (picture_h - pictureBegin_y);
				r_gc.setForeground(display.getSystemColor(SWT.COLOR_RED));
				r_gc.drawLine(s_coordinate_x, s_coordinate_y - s_length,
						s_coordinate_x, s_coordinate_y + s_length);
				r_gc.drawLine(s_coordinate_x - s_length, s_coordinate_y,
						s_coordinate_x + s_length, s_coordinate_y);
			}

			// 竖线
			picture_table_min_x = (table_min_x - table_min_x) / drawpictureRate_x
					+ pictureBegin_x;
			picture_table_max_x = (table_max_x - table_min_x) / drawpictureRate_x
					+ pictureBegin_x;
			picture_table_max_y = (drawpictureRate_y * picture_h - table_min_y + table_max_y)
					/ drawpictureRate_y - (picture_h - pictureBegin_y);
			picture_table_min_y = (drawpictureRate_y * picture_h - table_max_y + table_max_y)
					/ drawpictureRate_y - (picture_h - pictureBegin_y);

			for (int i = 0; i < table_width_line; i++) {
				picture_table_min_x = (min_x - table_min_x) / drawpictureRate_x
						+ pictureBegin_x;
				r_gc.setAlpha(35); // 透明度
				r_gc.drawLine(picture_table_min_x, picture_table_min_y,
						picture_table_min_x, picture_table_max_y);
				min_x += table_scale_w;
			}
			// 横线
			picture_table_min_x = (table_min_x - table_min_x) / drawpictureRate_x
					+ pictureBegin_x;
			for (int i = 0; i < table_height_line; i++) {
				picture_table_min_y = (drawpictureRate_y * picture_h - max_y + table_max_y)
						/ drawpictureRate_y - (picture_h - pictureBegin_y);
				r_gc.setAlpha(35); // 透明度
				r_gc.drawLine(picture_table_min_x, picture_table_min_y,
						picture_table_max_x, picture_table_min_y);
				max_y -= table_scale_h;
			}
			r_gc.copyArea(image, 0, 0);
			r_gc.drawImage(image, 0, 0);
			r_gc.dispose();
			compositeImage.setBackgroundImage(image);
			enforc = false; 
		}

因为对画图生成不太了解，上面的代码我认为是直接将图片画到了内存当中然后在设为Composite 的背景的，问题是我在一个放大的功能里重新画图设为背景，开始没什么问题，到了最后放的较大的时候图片北京图片就消失了。不知道是为甚么。有没有解决办法。谢谢各位高手了帮忙解决下好吗？

[yzg000123]

放大的时候我将图片image.dispose();了，然后又重新画图设为背景的。

[yzg000123]

[Quote=引用 1 楼 yzg000123 的回复:]
放大的时候我将图片image.dispose();了，然后又重新画图设为背景的。
[/Quote]
不是图片大的看不到了，是报异常了。

Exception in thread "main" org.eclipse.swt.SWTError: No more handles
	at org.eclipse.swt.SWT.error(SWT.java:3589)
	at org.eclipse.swt.graphics.Image.init(Image.java:1577)
	at org.eclipse.swt.graphics.Image.<init>(Image.java:174)
	at new_picture.Draw3D.drawPicture3D(Draw3D.java:520)
	at new_picture.Draw3D.magnify(Draw3D.java:871)
	at new_picture.Interface$10.widgetSelected(Interface.java:318)
	at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:227)
	at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:66)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:938)
	at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:3682)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3293)
	at new_picture.Interface.main(Interface.java:360)

[njclsc]

背景容器添加一个滚动条,这样放的在大都可以看到了,还有你的控件要有向对应的类型,