問題描述

如何從我的滾動視圖中刪除所有子視圖...

how do i remove all subviews from my scrollview...

我在滾動視圖中有一個 uiview 和它上方的按鈕，如下所示....

i have a uiview and a button above it in the scrollview something like this....

這是我在滾動視圖中添加子視圖的代碼

here is my code to add subview in scroll view

-(void)AddOneButton:(NSInteger)myButtonTag {
lastButtonNumber = lastButtonNumber + 1;

if ((lastButtonNumber == 1) || ((lastButtonNumber%2) == 1)) {
btnLeft = 8;}
else if ((lastButtonNumber == 2) || ((lastButtonNumber%2) == 0)) {
btnLeft = 162;
}
CGRect frame1 = CGRectMake(btnLeft, btnTop, 150, 150);
CGRect frame2 = CGRectMake(btnLeft, btnTop, 150, 150);
UIButton *Button = [UIButton buttonWithType:UIButtonTypeCustom];
Button.frame = frame1;
Button.tag = myButtonTag;
[Button addTarget:self action:@selector(buttonClick:) forControlEvents:UIControlEventTouchUpInside];
[Button setBackgroundColor:[UIColor clearColor]];
[Button setBackgroundImage:[UIImage imageNamed:@"WaitScreen.png"] forState:UIControlStateHighlighted];

    GraphThumbViewControllerobj = [[GraphThumbViewController alloc] initWithPageNumber:[[GraphIdArray objectAtIndex:myButtonTag]intValue]];
    GraphThumbViewControllerobj.view.frame=frame2;
    GraphThumbViewControllerobj.lblCounter.text=[NSString stringWithFormat:@"%d of %d",myButtonTag+1,flashCardsId.count];
    GraphThumbViewControllerobj.lblQuestion.text=[flashCardText objectAtIndex:myButtonTag];
    [myScrollView addSubview:GraphThumbViewControllerobj.view];


[myScrollView addSubview:Button];


if ((lastButtonNumber == 2) || ((lastButtonNumber%2) == 0)) {
btnTop = btnTop + 162;
}
if (btnTop+150 > myScrollView.frame.size.height) {
myScrollView.contentSize = CGSizeMake((myScrollView.frame.size.width), (btnTop+160));}
}

這是刪除子視圖的代碼

if(myScrollView!=nil)
{
        while ([myScrollView.subviews count] > 0) {
            //NSLog(@"subviews Count=%d",[[myScrollView subviews]count]);
            [[[myScrollView subviews] objectAtIndex:0] removeFromSuperview];
}

推薦答案

要從任何視圖中刪除所有子視圖，您可以遍歷子視圖并為每個子視圖發(fā)送 removeFromSuperview 調用:

To remove all the subviews from any view, you can iterate over the subviews and send each a removeFromSuperview call:

// With some valid UIView *view:
for(UIView *subview in [view subviews]) {
    [subview removeFromSuperview];
}

不過，這完全是無條件的，并且會刪除給定視圖中的所有子視圖.如果你想要更細粒度的東西，你可以采取幾種不同的方法:

This is entirely unconditional, though, and will get rid of all subviews in the given view. If you want something more fine-grained, you could take any of several different approaches:

• 維護您自己的不同類型的視圖數組，以便稍后以相同的方式向它們發(fā)送 removeFromSuperview 消息
• 保留您創(chuàng)建它們的所有視圖并保留指向這些視圖的指針，以便您可以根據需要單獨發(fā)送它們 removeFromSuperview
• 在上述循環(huán)中添加 if 語句，檢查類是否相等.例如，要僅刪除視圖中存在的所有 UIButton(或 UIButton 的自定義子類)，您可以使用以下內容:

• Maintain your own arrays of views of different types so you can send them removeFromSuperview messages later in the same manner
• Retain all your views where you create them and hold on to pointers to those views, so you can send them removeFromSuperview individually as necessary
• Add an if statement to the above loop, checking for class equality. For example, to only remove all the UIButtons (or custom subclasses of UIButton) that exist in a view, you could use something like:

// Again, valid UIView *view:
for(UIView *subview in [view subviews]) {
    if([subview isKindOfClass:[UIButton class]]) {
        [subview removeFromSuperview];
    } else {
        // Do nothing - not a UIButton or subclass instance
    }
}

這篇關于如何從滾動視圖中刪除子視圖?的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！