1、通过在textView中键盘上方添加一个toolBar来实现取消键盘的功能，可以添加其他功能：
1 UIToolbar * topView = [[UIToolbar alloc] initWithFrame:CGRectMake(0, 0, 320, 30)];
2 [topView setBarStyle:UIBarStyleBlackTranslucent];
3
4 UIBarButtonItem * btnSpace = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:self action:nil];
5 UIBarButtonItem * doneButton = [[UIBarButtonItem alloc] initWithTitle:@"完成" style:UIBarButtonItemStyleDone target:self action:@selector(dismissKeyBoard)];
6 NSArray * buttonsArray = @[btnSpace, doneButton];
7
8 [topView setItems:buttonsArray];
9 [_textView setInputAccessoryView:topView];
2、如果上方有一个navigationBar，则可以在bar上添加一个DONE按钮来取消键盘，如果bar上已经有其他功能按键，则可以弹出键盘前保存当前barButtonItem，然后在弹出键盘（利用shouldBeginEditing委托来触发）后用取消键盘按钮来替换：
1 - (BOOL)textViewShouldBeginEditing:(UITextView *)textView
2 {
3 self.rightButton = self.navigationItem.rightBarButtonItem;
4 UIBarButtonItem *doneButton = [[UIBarButtonItem alloc] initWithTitle:@"完成" style:UIBarButtonItemStyleDone target:self action:@selector(dismissKeyBoard)];
5 self.navigationItem.rightBarButtonItem = doneButton;
6 return YES;
7 }
键盘消失后再赋回原来的按钮：
- (void)dismissKeyBoard
{
[_textView resignFirstResponder];
self.navigationItem.rightBarButtonItem = self.rightButton;
}
