ios - 异步加载 UIViews
<p><p>我正在尝试异步加载 View 。问题是要加载的 View 的框架取决于异步加载的数据。换句话说,有一些很长的计算决定了在哪里实际显示 UIView。 </p>
<p>我知道尝试在线程中实际显示 UIView 时会出现问题,并且您应该始终将它们加载回主线程中,所以这是我一直在尝试的代码:</p>
<pre><code>asyncQueue = [ init];
[asyncQueue addOperationWithBlock:^{
// Do work to load the UIViews and figure out where they should be
UIButton *test = [ initWithFrame:];
[ addOperationWithBlock:^{
;
}
}];
}];
</code></pre>
<p>这一切都驻留在 UIView 容器中。</p></p>
<br><hr><h1><strong>Best Answer-推荐答案</ strong></h1><br>
<p><p>试试这样的:</p>
<pre><code>UIButton *test = [ initWithFrame:CGRectZero];
test.hidden = YES;
test.alpha = 0.0f;
;
dispatch_queue_t downloadQueue = dispatch_queue_create("myDownloadQueue",NULL);
dispatch_async(downloadQueue, ^
{
// do work to load UIViews and calculate frame
CGRect frameButton = ...;
dispatch_async(dispatch_get_main_queue(), ^
{
test.hidden = NO;
[UIView animateWithDuration:0.4f animations:^
{
test.frame = frameButton;
test.alpha = 1.0f;
}
completion:^(BOOL finished){}];
});
});
dispatch_release(downloadQueue);
</code></pre>
<p>这会将您的按钮添加到主线程中,但最初使其不可见。后台工作完成后,您将使其可见并使用动画设置框架。</p></p>
<p style="font-size: 20px;">关于ios - 异步加载 UIViews,我们在Stack Overflow上找到一个类似的问题:
<a href="https://stackoverflow.com/questions/12373850/" rel="noreferrer noopener nofollow" style="color: red;">
https://stackoverflow.com/questions/12373850/
</a>
</p>
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