iOS UITextField、UITextview弹出键盘上添

用于某些页面，弹出键盘无法轻易收回键盘，，可以添加此按钮，以方便某些占满的页面收回键盘。
核心就是：textField.inputAccessoryView

 UIToolbar* keyboardDoneButtonView = [[UIToolbar alloc] init];
    
    keyboardDoneButtonView.barStyle = UIBarStyleDefault;
    
    keyboardDoneButtonView.translucent = YES;
    
    keyboardDoneButtonView.tintColor = nil;
    
    [keyboardDoneButtonView sizeToFit];
    
    UIBarButtonItem *SpaceButton=[[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:nil action:nil]; // 让完成按钮显示在右侧
    
    UIBarButtonItem *doneButton = [[UIBarButtonItem alloc]initWithTitle:@"完成" style:UIBarButtonItemStyleDone target:self action:@selector(pickerDoneClicked)];
    
    [keyboardDoneButtonView setItems:[NSArray arrayWithObjects:SpaceButton, doneButton, nil]];
    
    _textField.inputAccessoryView = keyboardDoneButtonView;