iOS捕捉截屏事件并展示截图效果

摩拜单车、微信的截屏就做的比较人性化。

现在很多app开始支持用户截屏后，主动获取截图并弹出分享视图，这样用户就不用去相册去找了，感觉体验不错，今天就分享一下 截屏开发的心得，希望能帮助ios的朋友。

ios7之后，苹果开放出一个通知：uiapplicationuserdidtakescreenshotnotification，截屏时系统就会发出这个通知，需要你注册这个通知，就能捕捉到截屏图片。

下面的代码，实现的是用户截屏后，捕获到截屏图片，展示出来：

//注册截屏通知

 [[nsnotificationcenter defaultcenter] addobserver:self
    selector:@selector(getscreenshot:)
    name:uiapplicationuserdidtakescreenshotnotification object:nil];

截屏后捕捉到事件：

- (void)getscreenshot:(nsnotification *)notification{
 nslog(@"捕捉截屏事件");

 //获取截屏图片
 uiimage *image = [uiimage imagewithdata:[self imagedatascreenshot]];

 //显示图片
 uiimageview *imgv = [[uiimageview alloc]initwithimage:image];
 imgv.frame = [uiscreen mainscreen].bounds;

 uiview *backview = [[uiview alloc]initwithframe:cgrectmake(0, 0, screen_width, screen_height)];
 backview.backgroundcolor = [[uicolor graycolor] colorwithalphacomponent:0.8];

 uibutton *sharebtn = [uibutton buttonwithtype:uibuttontypesystem];
 sharebtn.titlelabel.font = [uifont systemfontofsize:17.0];
 [sharebtn settintcolor:[uicolor whitecolor]];
 sharebtn.frame = cgrectmake(screen_width/5,screen_height ,screen_width*3/5,50);
 [sharebtn.layer setmaskstobounds:yes];
 [sharebtn.layer setborderwidth:1];
 sharebtn.layer.cornerradius = 6;
 [sharebtn settitle:@"分享给好友" forstate:uicontrolstatenormal];
 sharebtn.backgroundcolor = [soufunimutilityhelper colorwithhexstring:@"#b22222"];
 [sharebtn addtarget:self action:@selector(sharebtn:) forcontrolevents:uicontroleventtouchupinside];

 [backview addsubview:imgv];
 [backview addsubview:sharebtn];

 uiwindow *window = [uiapplication sharedapplication].keywindow;
 [window addsubview:backview];

 [uiview animatewithduration:1.0 animations:^{
  imgv.transform = cgaffinetransformmakescale(0.8, 0.8);
  sharebtn.transform = cgaffinetransformmaketranslation(0, -50);
 }];
 //3秒后消失
 dispatch_after(dispatch_time(dispatch_time_now, (int64_t)(3 * nsec_per_sec)), dispatch_get_main_queue(), ^{
  [backview removefromsuperview];
 });
}

获取截屏图片data：

- (nsdata *)imagedatascreenshot
{
 cgsize imagesize = cgsizezero;
 imagesize = [uiscreen mainscreen].bounds.size;

 uigraphicsbeginimagecontextwithoptions(imagesize, no, 0);
 cgcontextref context = uigraphicsgetcurrentcontext();
 for (uiwindow *window in [[uiapplication sharedapplication] windows])
 {
  cgcontextsavegstate(context);
  cgcontexttranslatectm(context, window.center.x, window.center.y);
  cgcontextconcatctm(context, window.transform);
  cgcontexttranslatectm(context, -window.bounds.size.width * window.layer.anchorpoint.x, -window.bounds.size.height * window.layer.anchorpoint.y);
    if ([window respondstoselector:@selector(drawviewhierarchyinrect:afterscreenupdates:)])
  {
   [window drawviewhierarchyinrect:window.bounds afterscreenupdates:yes];
  }
  else
  {
   [window.layer renderincontext:context];
  }
  cgcontextrestoregstate(context);
 }

 uiimage *image = uigraphicsgetimagefromcurrentimagecontext();
 uigraphicsendimagecontext();

 return uiimagepngrepresentation(image);
}

按钮点击事件：

-(void)sharebtn:(uibutton *)sender{

/*
 分享代码 
*/
}

以上就是截屏后的事例代码，最后附上效果图：

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。