受於UITextFiled 使用的侷限性,所以在日常工作中我們可能還是經常需要使用到 UITextView,所以本文的目的就是一起學習瞭解一下 UITextView 的受用
1.創建並初始化
創建UITextView的文件,並在.h文件中寫入如下代碼:
- #import <UIKit/UIKit.h>
- @interface TextViewController : UIViewController <UITextViewDelegate>
- {
- UITextView *textView;
- }
- @property (nonatomic, retain) UITextView *textView;
- @end
在.m文件中初始化這個textview,寫入代碼如下:
- self.textView = [[[UITextView alloc] initWithFrame:self.view.frame]autorelease]; //初始化大小並自動釋放
- self.textView.textColor = [UIColor blackColor];//設置textview裏面的字體顏色
- self.textView.font = [UIFont fontWithName:@"Arial" size:18.0];//設置字體名字和字體大小
- self.textView.delegate = self;//設置它的委託方法
- self.textView.backgroundColor = [UIColor whiteColor];//設置它的背景顏色
- self.textView.text = @"Now is the time for all good developers tocome to serve their country.\n\nNow is the time for all good developers to cometo serve their country.";//設置它顯示的內容
- self.textView.returnKeyType = UIReturnKeyDefault;//返回鍵的類型
- self.textView.keyboardType = UIKeyboardTypeDefault;//鍵盤類型
- self.textView.scrollEnabled = YES;//是否可以拖動
- self.textView.autoresizingMask = UIViewAutoresizingFlexibleHeight;//自適應高度
- [self.view addSubview: self.textView];//加入到整個頁面中
2. UITextView退出鍵盤的幾種方式
因爲你點擊UITextView會出現鍵盤,如果你退出鍵盤,有如下幾種方式:
(1)如果你程序是有導航條的,可以在導航條上面加多一個Done的按鈕,用來退出鍵盤,當然要先實UITextViewDelegate。代碼如下:
- - (void)textViewDidBeginEditing:(UITextView *)textView {
- UIBarButtonItem *done = [[[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(leaveEditMode)] autorelease];
- self.navigationItem.rightBarButtonItem = done;
- }
- - (void)textViewDidEndEditing:(UITextView *)textView {
- self.navigationItem.rightBarButtonItem = nil;
- }
- - (void)leaveEditMode {
- [self.textView resignFirstResponder];
- }
(2)如果你的textview裏不用回車鍵,可以把回車鍵當做退出鍵盤的響應鍵。代碼如下:
- #pragma mark - UITextView Delegate Methods
- -(BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text
- {
- if ([text isEqualToString:@"\n"]) {
- [textView resignFirstResponder];
- return NO;
- }
- return YES;
- }
這樣無論你是使用電腦鍵盤上的回車鍵還是使用彈出鍵盤裏的return鍵都可以達到退出鍵盤的效果。
(3)還有你也可以自定義其他加載鍵盤上面用來退出,比如在彈出的鍵盤上面加一個view來放置退出鍵盤的Done按鈕。
代碼如下:
- UIToolbar * topView = [[UIToolbar alloc]initWithFrame:CGRectMake(0, 0, 320, 30)];
- [topView setBarStyle:UIBarStyleBlack];
- UIBarButtonItem * helloButton = [[UIBarButtonItem alloc]initWithTitle:@"Hello" style:UIBarButtonItemStyleBordered target:self action:nil];
- UIBarButtonItem * btnSpace = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:self action:nil];
- UIBarButtonItem * doneButton = [[UIBarButtonItem alloc]initWithTitle:@"Done" style:UIBarButtonItemStyleDone target:self action:@selector(dismissKeyBoard)];
- NSArray * buttonsArray = [NSArray arrayWithObjects:helloButton,btnSpace,doneButton,nil];
- [doneButton release];
- [btnSpace release];
- [helloButton release];
- [topView setItems:buttonsArray];
- [tvTextView setInputAccessoryView:topView];
- -(IBAction)dismissKeyBoard
- {
- [tvTextView resignFirstResponder];
- }
(4)設置UITextView圓角問題
做法是在 #import QuartzCore/QuartzCore.h 後,便能調用[textView.layer setCornerRadius:10]; 來把 UITextView 設定圓角
(5)UITextView根據文本大小自適應高度
通過實現文本字數來確定高度,如下:
- NSString * desc = @"Description it is a test font, and don't become angry for which i use to do here.Now here is a very nice party from american or not!";
- CGSize size = [desc sizeWithFont:[UIFont systemFontOfSize:14] constrainedToSize:CGSizeMake(240, 2000) lineBreakMode:UILineBreakModeWordWrap];
只有UILabel需要定義的numberoflines爲0,即不做行數的限制。如下:
- [label setNumberOfLines:0];
- [label setFrame:CGRectMake(40, 135, 240, size.height+10)];
- [label setText:desc];
(6)UITextView自定選擇文字後的菜單
在ViewDidLoad中加入:
- UIMenuItem *menuItem = [[UIMenuItem alloc]initWithTitle:@"分享到新浪微博" action:@selector(changeColor:)];
- UIMenuController *menu = [UIMenuController sharedMenuController];
- [menu setMenuItems:[NSArray arrayWithObject:menuItem]];
- [menuItem release];
當然上面那個@selector裏面的changeColor方法還是自己寫吧,也就是說點擊了我們自定義的菜單項後會觸發的方法。
然後還得在代碼里加上一個方法:
- -(BOOL)canPerformAction:(SEL)action withSender:(id)sender
- {
- if(action ==@selector(changeColor:))
- {
- if(textView.selectedRange.length>0)
- return YES;
- }
- return NO;
- }
實現後如下圖:
今天的UITextView就講到這裏,主要講了UITextView的初始化和開發中會遇到的一些問題和自定義等問題。謝謝大家支持哈。