IOS数字键盘左下角添加完成按钮的实现方法

- (void)adddonebuttontonumpadkeyboard 
{ 
  uibutton *donebutton = [uibutton buttonwithtype:uibuttontypecustom]; 
  if (systemversion < 8.0){ 
    donebutton.frame = cgrectmake(0, 163, 106, 53); 
  }else{ 
    donebutton.frame = cgrectmake(0, screen_size.height-53, 106, 53); 
  } 
  donebutton.tag = num_pad_done_button_tag; 
  donebutton.adjustsimagewhenhighlighted = no; 
  [donebutton settitle:@"完成" forstate:uicontrolstatenormal]; 
  [donebutton settitlecolor:[uicolor blackcolor] forstate:uicontrolstatenormal]; 
  [donebutton addtarget:self action:@selector(donebutton:) forcontrolevents:uicontroleventtouchupinside]; 
   
  nsarray *windowarr = [[uiapplication sharedapplication] windows]; 
  if (windowarr != nil && windowarr.count > 1){ 
    uiwindow *needwindow = [windowarr objectatindex:1]; 
    uiview *keyboard; 
    for(int i = 0; i < [needwindow.subviews count]; i++) { 
      keyboard = [needwindow.subviews objectatindex:i]; 
      nslog(@"%@", [keyboard description]); 
      if(([[keyboard description] hasprefix:@"<uiperipheralhostview"] == yes) || ([[keyboard description] hasprefix:@"<uikeyboard"] == yes) || ([[keyboard description] hasprefix:@"<uiinputsetcontainerview"] == yes)){ 
         
        uiview *donebuttonview = [keyboard viewwithtag:num_pad_done_button_tag]; 
        if (donebuttonview == nil){ 
          [keyboard addsubview:donebutton]; 
        } 
      } 
    } 
  } 
} 
 
-(void)removedonebuttonfromnumpadkeyboard 
{ 
  uiview *donebutton = nil; 
 
  nsarray *windowarr = [[uiapplication sharedapplication] windows]; 
  if (windowarr != nil && windowarr.count > 1){ 
    uiwindow *needwindow = [windowarr objectatindex:1]; 
    uiview *keyboard; 
    for(int i = 0; i < [needwindow.subviews count]; i++) { 
      keyboard = [needwindow.subviews objectatindex:i]; 
      if(([[keyboard description] hasprefix:@"<uiperipheralhostview"] == yes) || ([[keyboard description] hasprefix:@"<uikeyboard"] == yes) || ([[keyboard description] hasprefix:@"<uiinputsetcontainerview"] == yes)){ 
        donebutton = [keyboard viewwithtag:num_pad_done_button_tag]; 
        if (donebutton != nil){ 
          [donebutton removefromsuperview]; 
        } 
      } 
    } 
  } 
}