Question

我需要根据UIInterfaceOrientation显示不同大小的UIImage。现在的问题是，每当程序改变其方向时，图像仍然存在，而新图像与其重叠。这就是我所拥有的

UIView *logoView;

UIImage *image = [UIImage imageNamed:@"pic.png"];
UIImageView *imageView = [[UIImageView alloc] initWithImage:image];
[logoView removeFromSuperview];
CGRect rect;
UIInterfaceOrientation newOrientation =  [UIApplication sharedApplication].statusBarOrientation;
if(newOrientation == UIInterfaceOrientationLandscapeLeft || newOrientation == UIInterfaceOrientationLandscapeRight)
{
    rect = CGRectMake(0, 0, self.view.bounds.size.width/2, self.view.bounds.size.height/4);
    logoView = [[UIView alloc] initWithFrame:CGRectMake(0,0,self.view.bounds.size.width/2, self.view.bounds.size.height/4)];
}

else if (newOrientation == UIInterfaceOrientationPortrait || newOrientation == UIInterfaceOrientationPortraitUpsideDown)
{
    rect = CGRectMake(0, 0, self.view.bounds.size.width, self.view.bounds.size.height/4);
    logoView = [[UIView alloc] initWithFrame:CGRectMake(0,0,self.view.bounds.size.width, self.view.bounds.size.height/4)];
}
imageView.frame = logoView.bounds;
[logoView addSubview:imageView];


[self.view addSubview:logoView];

Answer 1

问题是logoView是一个局部变量。所以[logoView removeFromSuperview]将无效。

让logoView 属性或类变量会修复它。

Answer 2

创建全局logoView

如果不为null则从superview

中删除它

    if(logoView){

    [logoView removeFromSuperview];
logoView = nil;
    }

如果它为null则只进行初始化

if(newOrientation == UIInterfaceOrientationLandscapeLeft || newOrientation == UIInterfaceOrientationLandscapeRight)
{
    rect = CGRectMake(0, 0, self.view.bounds.size.width/2, self.view.bounds.size.height/4);
if(!logoView){
    logoView = [[UIView alloc] initWithFrame:CGRectMake(0,0,self.view.bounds.size.width/2, self.view.bounds.size.height/4)];
}
}




else if (newOrientation == UIInterfaceOrientationPortrait || newOrientation == UIInterfaceOrientationPortraitUpsideDown)
{
    rect = CGRectMake(0, 0, self.view.bounds.size.width, self.view.bounds.size.height/4);
if(!logoView){
    logoView = [[UIView alloc] initWithFrame:CGRectMake(0,0,self.view.bounds.size.width, self.view.bounds.size.height/4)];
}
}

Answer 3

[logoView removeFromSuperview];不会删除旧的logoView。事实上，如果您没有将logoView作为控件中的属性，则不会获取logoView并将其从self.view中删除。< / p>

@interface ViewController ()

@property (nonatomic, strong) UIView *logoView;//You can keep it and get it when you want to remove it.

@end

然后：

[self.logoView removeFromSuperview];//get the logoView and remove it.
UIView *logoView;

UIImage *image = [UIImage imageNamed:@"pic.png"];
UIImageView *imageView = [[UIImageView alloc] initWithImage:image];

CGRect rect;
UIInterfaceOrientation newOrientation =  [UIApplication sharedApplication].statusBarOrientation;
if(newOrientation == UIInterfaceOrientationLandscapeLeft || newOrientation == UIInterfaceOrientationLandscapeRight) {
    rect = CGRectMake(0, 0, self.view.bounds.size.width/2, self.view.bounds.size.height/4);
    logoView = [[UIView alloc] initWithFrame:CGRectMake(0,0,self.view.bounds.size.width/2, self.view.bounds.size.height/4)];
} else if (newOrientation == UIInterfaceOrientationPortrait || newOrientation == UIInterfaceOrientationPortraitUpsideDown) {
    rect = CGRectMake(0, 0, self.view.bounds.size.width, self.view.bounds.size.height/4);
    logoView = [[UIView alloc] initWithFrame:CGRectMake(0,0,self.view.bounds.size.width, self.view.bounds.size.height/4)];
}
imageView.frame = logoView.bounds;

self.logoView = logoView;//keep logoView

[logoView addSubview:imageView];

[self.view addSubview:logoView];//add logoView to self.view

Answer 4

设置标记以删除UIView。我希望它对你有用

 logoView.tag = 108;  //set the tag
 [[self.view viewWithTag:108]removeFromSuperview];   //remove the view the superview

或者将变量分配给public＆＃34; logoView＆＃34;

UIView没有被删除

4 个答案: