Question

我已在我的应用中编写此代码：

- (IBAction)ZoomInFunction{
@try{
    UITextField *test  = (UITextField *)[self.view viewWithTag:indexNews];
    NSLog(@"INDEX NEWS : %d", indexNews);

    UIFont *font = test.font;
    if(test.font == [font fontWithSize:22])
        test.font = [font fontWithSize:22];
    else
        test.font = [font fontWithSize:font.pointSize+2];
}@catch (NSException *err) {
    NSLog(@"Error handler : %@", err);
}

}

- (IBAction)ZoomOutFunction{
@try {
    UITextField *test  = (UITextField *)[self.view viewWithTag:indexNews];

    UIFont *font = test.font;
    if(test.font == [font fontWithSize:14])
        test.font = [font fontWithSize:14];
    else
        test.font = [font fontWithSize:font.pointSize-2];
}@catch (NSException *err) {
    NSLog(@"Error handler : %@", err);

}

有时代码运行良好，但有时会显示错误，如此。

错误处理程序： - [UIView font]：无法识别的选择器发送到实例0xac70780

Answer 1

仔细阅读此Apple文章，您将了解IOS中的放大和缩小功能。

以下是行动中的代码：

       UITextView *textView = [UITextView alloc] initWithFrame:CGRectMake(0, 0, 320, 200)];
    UIPinchGestureRecognizer *gestureRecognizer = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(changeFontSize:)];
    [textView addGestureRecognizer:gestureRecognizer];

- (void)changeFontSize:(UIPinchGestureRecognizer *)gestureRecognizer 
 {
    UITextView *textView = (UITextView *)gestureRecognizer.view;
    float yourFontSize = gestureRecognizer.scale * FONT_SIZE;
    textView.font = [UIFont systemFontOfSize:yourFontSize];
 }

http://developer.apple.com/library/ios/#documentation/windowsviews/conceptual/UIScrollView_pg/ZoomZoom/ZoomZoom.html

Answer 2

可以在UITextView上进行缩放。 UITextView在键入文本时动态扩展，并在用户捏住屏幕时进行缩放（类似行为可在TinyPost中找到）。

在viewDidLoad

中应用此功能

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

    UIPinchGestureRecognizer *gestureRecognizer = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(scaleTextView:)];

    [test addGestureRecognizer:gestureRecognizer];

并像这样在UITextView上应用zoomIn和out

- (void)scaleTextView:(UIPinchGestureRecognizer *)pinchGestRecognizer{

     CGFloat scale = pinchGestRecognizer.scale;

    createTextView.font = [UIFont fontWithName:createTextView.font.fontName size:createTextView.font.pointSize*scale];

    [self textViewDidChange:createTextView];       
}

- (void)textViewDidChange:(UITextView *)textView{

     CGSize textSize = textView.contentSize;

     textView.frame = CGRectMake(CGRectGetMinX(textView.frame), CGRectGetMinY(textView.frame), textSize.width, textSize.height); //update the size of the textView  
 }

我希望它适合你。

Answer 3

我已经申请了，我得到了适当的解决方案。这是由于以下代码行

UITextField *test  = (UITextField *)[self.view viewWithTag:indexNews];

有些时候你通过viewWithTag：indexNews从self.view获取UITextView，那么这个indexNews标记值已经分配给其他UIView，所以这行代码获取UIView而不是UITextField。所以它无法通过UIView调用Font方法，因此它返回错误。我有一个更好的解决方案

在你的.h文件中为UITextView实现一个插座

@property (weak, nonatomic) IBOutlet UITextView *fontTextView;

在.m文件中

@synthesize fontTextView;

- (IBAction)ZoomInFunction{
    @try{

        UIFont *font = fontTextView.font;
        if(fontTextView.font == [font fontWithSize:22])
            fontTextView.font = [font fontWithSize:22];
        else
            fontTextView.font = [font fontWithSize:font.pointSize+2];
    }@catch (NSException *err) {
        NSLog(@"Error handler : %@", err);
    }

}

- (IBAction)ZoomOutFunction{
    @try {

        UIFont *font = fontTextView.font;
        if(fontTextView.font == [font fontWithSize:14])
            fontTextView.font = [font fontWithSize:14];
        else
            fontTextView.font = [font fontWithSize:font.pointSize-2];
    }@catch (NSException *err) {
        NSLog(@"Error handler : %@", err);

    }
}

我希望它适用于您的代码。感谢

放大和缩小ios中的特色

3 个答案: