Question

我有一个UITextView（iOS4.2.1 - iPad），我试图将其作为一种“下拉窗口”，供用户根据需要调整大小。我正在使用平移手势识别器来跟踪用户手指，然后根据手指移动的距离调整UITextView框架的大小。一切都很好 - 除了UITextView中的文本在帧扩展超过一定大小后被“切断”。如果我与文本交互（用手指轻弹/滚动），它都会正确重新绘制。我可以在一个非常小的程序中重现这一点 - 见下文。有人见过这个吗？我已经尝试了所有通常的'黑客'（即强行设置滚动位置 - 修改文本等 - 所有'工作'但有缺点）

提前感谢任何指示...

重现它的测试程序如下（只需创建一个基于标准视图的iPad应用程序，然后将以下内容粘贴到主ViewController中。）运行程序然后将手指向下拖动到页面 - 只有前8行左右将显示文字。

@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

您可能希望在几何体更改后尝试在文本视图上调用setNeedsDisplay。

调整大小后UITextView没有“重新绘制”

1 个答案: