GWT通过JSNI打印Web页面内容

程序员文章站 2024-01-26 10:06:28

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在GWT中通过JSNI调用JS脚本去执行web页面打印：
首先是预览打印界面，代码如下：


package net.carefx.sde.editor.web.editor.client.partogram;

import net.carefx.component.editor.web.client.jsni.PartogramScript;

import com.extjs.gxt.ui.client.Style.HorizontalAlignment;
import com.extjs.gxt.ui.client.Style.Scroll;
import com.extjs.gxt.ui.client.event.BaseEvent;
import com.extjs.gxt.ui.client.event.ButtonEvent;
import com.extjs.gxt.ui.client.event.Events;
import com.extjs.gxt.ui.client.event.Listener;
import com.extjs.gxt.ui.client.event.SelectionListener;
import com.extjs.gxt.ui.client.widget.Dialog;
import com.extjs.gxt.ui.client.widget.LayoutContainer;
import com.extjs.gxt.ui.client.widget.button.Button;
import com.extjs.gxt.ui.client.widget.layout.FitLayout;
import com.google.gwt.dom.client.Element;
import com.google.gwt.user.client.DOM;
import com.google.gwt.user.client.Window;
import com.google.gwt.user.client.ui.Image;
/**
 * 产程图预览打印窗口
 * @author icarefx-lqy
 *
 */
public class PartogramPreview extends Dialog 
{
	//向产程图绘制程序发出请求资源：imgUrl + imgName = 请求地址
//	private String imgUrl = "http://localhost:8080/chanchengtu/img?";
	private String imgUrl = null;
	private String imgName;
	private PartogramScript script;

	public PartogramPreview (String imgName, String imgUrl)
	{
		this.imgUrl = imgUrl;
		this.imgName = imgName;
		script = new PartogramScript();
		initUI();
	}

	private void initUI ()
	{
		setSize (960, Window.getClientHeight () - 64);
		setHeading("产程图预览");
		setLayout(new FitLayout());

		final LayoutContainer lc = new LayoutContainer();
		lc.setId("imgContainner");//set div.id="imgContainner";
		Image img = new Image();
		img.setUrl(imgUrl+imgName);
		lc.add(img);
		lc.setScrollMode(Scroll.AUTO);
		this.setButtons("");
		this.setButtonAlign(HorizontalAlignment.CENTER);
		this.add(lc);

		Button print = new Button("打印");
		print.addSelectionListener(new SelectionListener<ButtonEvent>() {

			@Override
			public void componentSelected(ButtonEvent ce) {
				// TODO 调用打印函数
				script.excutePrint(imgUrl+imgName);
			}
		});

		Button cancel = new Button("取消");
		cancel.addSelectionListener(new SelectionListener<ButtonEvent>() {

			@Override
			public void componentSelected(ButtonEvent ce) {
				// TODO 关闭预览打印
				hide();
			}
		});
		this.addButton(print);
		this.addButton(cancel);

	}	
}

然后是JSNI调用：


package net.carefx.component.editor.web.client.jsni;
/**
 * 产程图打印脚本
 * @author icarefx-lqy
 *
 */
public class PartogramScript {

	public PartogramScript()
	{}

	public native void excutePrint(String id)
	/*-{
		$wnd._divprint(id);
	}-*/;

	public native void getElementById (String id)
	/*-{
	 	$wnd._getdivbyid(id);
	}-*/;
}

JSNI调用的JS脚本：


/**
 * 打印DIV包裹的内容
 * @param printdiv 
 * @returns {Boolean} 
 */
function _divprint (id)
{
	var win = window.open('','','width=925,height=1055');;
	var headstr = "<html><head><title></title></head><body>"; 
	var img = "<img src='"+id+"' />";
	var footstr = "</body></html>"; 
	win.document.open("text/html","replace");
	win.document.writeln(headstr);
	win.document.writeln(img);
	win.document.write(footstr);
	win.document.close();
	win.print();
}