UITextView在重新調整大小後不會「重繪」

Question

我有一個UITextView（iOS4.2.1 - iPad），我正在嘗試將其製作成一種「下拉窗口」，供用戶在他們認爲合適時調整大小。我使用平移手勢識別器跟蹤用戶手指，然後根據手指移動的距離調整UITextView框架的大小。一切都很好 - 除了UITextView中的文本一旦幀被擴展超過一定的大小就會被「切碎」。如果我與文本交互（輕彈/用我的手指滾動），它都可以正確重繪。我可以在一個非常小的程序中重現這一點 - 請參閱下文。其他人看過這個？我已經嘗試了所有常用的「黑客」（即強行設置滾動條的位置 - 修改文本等等 - 所有的工作「，但也有缺點）

預先感謝任何指針...

測試重現它的程序如下（只需創建一個基於標準視圖的iPad應用程序，然後將以下內容粘貼到主ViewController中。）運行該程序，然後將手指向下拖動頁面 - 僅顯示前8行文本。

@implementation TextViewTestViewController 

- (void)createAndLoadTextView 
{ 
    theTextView = [[UITextView alloc] initWithFrame:CGRectZero]; 
    theTextView.font = [UIFont systemFontOfSize:27]; 

    theTextView.backgroundColor = [UIColor redColor]; 
    theTextView.opaque = YES; 

    theTextView.text = @"1 sdnaslkdjfnaskjdnfkjsndfsdfknknskdfnlk\n" 
         "2 sdnaslkdjfnaskjdnfkjsndfsdfknknskdfnlk\n" 
         "3 sdnaslkdjfnaskjdnfkjsndfsdfknknskdfnlk\n" 
         "4 sdnaslkdjfnaskjdnfkjsndfsdfknknskdfnlk\n" 
         "5 sdnaslkdjfnaskjdnfkjsndfsdfknknskdfnlk\n" 
         "6 sdnaslkdjfnaskjdnfkjsndfsdfknknskdfnlk\n" 
         "7 sdnaslkdjfnaskjdnfkjsndfsdfknknskdfnlk\n" 
         "8 sdnaslkdjfnaskjdnfkjsndfsdfknknskdfnlk\n" 
         "9 sdnaslkdjfnaskjdnfkjsndfsdfknknskdfnlk\n" 
         "10 sdnaslkdjfnaskjdnfkjsndfsdfknknskdfnlk\n" 
         "11 sdnaslkdjfnaskjdnfkjsndfsdfknknskdfnlk\n" 
         "12 sdnaslkdjfnaskjdnfkjsndfsdfknknskdfnlk\n" 
         "13 sdnaslkdjfnaskjdnfkjsndfsdfknknskdfnlk\n" 
         "14 sdnaslkdjfnaskjdnfkjsndfsdfknknskdfnlk\n" 
         "15 sdnaslkdjfnaskjdnfkjsndfsdfknknskdfnlk\n" 
         "16 sdnaslkdjfnaskjdnfkjsndfsdfknknskdfnlk\n"; 

    [self.view addSubview:theTextView]; 
} 

- (void)viewDidLoad 
{ 
    [super viewDidLoad]; 

    [self createAndLoadTextView]; 

    UIPanGestureRecognizer* panGesture = [[[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(onPanGesture:)] autorelease];  
    [self.view addGestureRecognizer:panGesture]; 

    UITapGestureRecognizer* tapGesture = [[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(onTapGesture:)] autorelease];  
    [self.view addGestureRecognizer:tapGesture]; 
} 

- (void)onPanGesture:(UIPanGestureRecognizer*)gesture 
{ 
    if (gesture.state == UIGestureRecognizerStateBegan ||gesture.state == UIGestureRecognizerStateChanged) 
    { 
     CGFloat yDelta = [gesture translationInView:self.view].y; 

     [gesture setTranslation:CGPointZero inView:self.view]; 

     theTextView.frame = CGRectMake(0, 0, self.view.bounds.size.width, theTextView.bounds.size.height + yDelta); 
    } 
} 

- (void)onTapGesture:(UIPanGestureRecognizer*)gesture 
{ 
    //'reset' 

    [theTextView removeFromSuperview]; 
    [theTextView release]; 
    theTextView = nil; 

    [self createAndLoadTextView]; 
} 

@end 

Answer 1

您可能想要在幾何更改後嘗試在文本視圖上調用setNeedsDisplay。