UITextView里换行实现（键盘上附加一个完成按钮）

     // 1、创建UITextView

    UITextView* tv = [[UITextView alloc] initWithFrame:CGRectMake(10, 10, 300, 200)];

    [tv setFont:[UIFont systemFontOfSize:19.0]];

    tv.tag = 1001;

    tv.returnKeyType = UIReturnKeyNext; // 下一行

    tv.delegate = self;

    [self.view addSubview:tv];

    

    // 2、键盘上方附加一个toolbar，toolbar上有个完成按钮

    UIToolbar* keyboardDoneButtonView = [[UIToolbar alloc] init];

    keyboardDoneButtonView.barStyle = UIBarStyleBlack;

    keyboardDoneButtonView.translucent = YES;

    keyboardDoneButtonView.tintColor = nil;

    [keyboardDoneButtonView sizeToFit];

    // toolbar上的2个按钮

    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:UIBarButtonItemStyleBordered target:self

                                                                  action:@selector(pickerDoneClicked)];

    [keyboardDoneButtonView setItems:[NSArray arrayWithObjects:SpaceButton, doneButton, nil]];

    tv.inputAccessoryView = keyboardDoneButtonView;

           // 3 、键盘上方附加的完成按钮触发函数

   -(void)pickerDoneClicked

   {

       UITextView* view = (UITextView*)[self.view viewWithTag:1001];

       [view resignFirstResponder];

   }