using system;  
using system.collections.generic;  
using system.componentmodel;  
using system.data;  
using system.drawing;  
using system.io;  
using system.linq;  
using system.net;  
using system.text;  
using system.threading;  
using system.threading.tasks;  
using system.windows.forms;  
using newtonsoft.json;  
using newtonsoft.json.linq;
namespace 图片下载器 {  
    public partial class form1 : form {  
        private string dir;  
        public form1() {  
            control.checkforillegalcrossthreadcalls = false;//这种方法不推荐使用，即不检查跨线程操作，应该使用委托的  
            initializecomponent();  
        }
private void butselect_click(object sender , eventargs e) {  
            folderbrowserdialog dlg = new folderbrowserdialog();  
            if (dlg.showdialog() == system.windows.forms.dialogresult.ok) {  
                textdir.text = dlg.selectedpath;
}  
        }  
        public static int pagecount = 1;  
        private void showpages() {  
            this.textshow.appendtext(目前正在下载第 + pagecount + 页\n);  
        }  
        private void butstart_click(object sender , eventargs e) {  
            string key = textkeywords.text;  
            if (string.isnullorempty(key)) {//检测关键字  
                messagebox.show(请输入关键词！);  
                return;  
            }  
            if (string.isnullorempty(textdir.text)) {//检测路径  
                messagebox.show(请选择路径！);  
                return;  
            }  
            dir = textdir.text;  
            if (!dir.endswith(\\)) {  
                dir = dir + \\;  
            }  
            thread thread = new thread(() => {//启动一个新线程  
                process(key);  
            });  
            thread.start();//线程启动  
        }
private void process(string key) {  
            int count = (int)numericupdown.value;//请求的页面数量  
            for (int i = 0 ; i                 pagecount = i + 1;  
                showpages();  
                httpwebrequest req = (httpwebrequest)webrequest.create(http://image.baidu.com/search/avatarjson?tn=resultjsonavatarnew&ie=utf-8&word= + uri.escapeuristring(key) + &cg=girl&pn= + (i + 1) * 60 + &rn=60&itg=0&z=0&fr=&width=&height=&lm=-1&ic=0&s=0&st=-1&gsm=360600003c);  
                using (httpwebresponse res = (httpwebresponse)req.getresponse()) {  
                    if (res.statuscode == httpstatuscode.ok) {  
                        using (stream stream = res.getresponsestream()) {  
                            try {  
                                download(stream);  
                            } catch (exception e) {  
                                textshow.begininvoke(new action(() => {  
                                    textshow.appendtext(e.message + environment.newline);  
                                }));  
                            }  
                        }  
                    } else {  
                        messagebox.show(获取第 + i + 页失败！ + res.statuscode);  
                    }  
                }  
            }  
        }
private void download(stream stream) {  
            using (streamreader reader = new streamreader(stream)) {  
                string json = reader.readtoend();  
                jobject objroot = (jobject)jsonconvert.deserializeobject(json);  
                jarray imgs = (jarray)objroot[imgs];  
                for (int j = 0 ; j                     jobject img = (jobject)imgs[j];  
                    string objurl = (string)img[objurl];//http://hibiadu....../1.jpg  
                    // textshow.appendtext(objurl + environment.newline);  
                    //保存的路径是：destdir；  
                    try {  
                        downloadimage(objurl);//避免一个方法中的代码过于复杂  
                    } catch (exception ex) {  
                        //子线程的代码中操作界面控件要使用begininvoke  
                        textshow.begininvoke(new action(() => {  
                            textshow.appendtext(ex.message + environment.newline);  
                        }));  
                    }  
                }  
            }  
        }  
        private void downloadimage(string objurl) {  
            //得到保存的路径  
            string path = path.combine(dir , path.getfilename(objurl));  
            httpwebrequest req = (httpwebrequest)webrequest.create(objurl);  
            req.referer = http://image.baidu.com/;//欺骗网站服务器这是从百度图片发出的  
            using (httpwebresponse res = (httpwebresponse)req.getresponse()) {  
                if (res.statuscode == httpstatuscode.ok) {  
                    using (stream stream = res.getresponsestream())  
                    using (stream filestream = new filestream(path , filemode.create)) {  
                        stream.copyto(filestream);  
                    }  
                } else {  
                    throw new exception(下载失败 + res.statuscode);  
                }  
            }  
        }  
    }  
}