UISearchBar display bug: text too far left, overlapping the magnifying glass icon

问题

I have encountered the weirdest display bug with my UISearchBar.
Here is my code that works perfectly in another app. (I create the search bar in code because a xib file is not feasible.)

searchBar = [[UISearchBar alloc] initWithFrame:
    CGRectMake(0, 0, self.tableView.frame.size.width, 44)];
searchBar.delegate = self;
searchController = [[UISearchDisplayController alloc] 
                   initWithSearchBar:searchBar contentsController:self];
searchController.delegate = self;
searchController.searchResultsDataSource = self;
searchController.searchResultsDelegate = self;
self.tableView.tableHeaderView = searchBar;

The search functionality etc. works fine. But strangely, the search bar looks like this, both on the device and the simulator:

• The placeholder string should not be there, but further to the right.
• When I enter search text it also starts too far left, with the magnifying glass icon showing through.
• Also, setting searchBar.placeholder or searchBar.prompt to @"" or nil does not remove this "Search" placeholder. (However, a
  searchBar.placeholder = @"FooBar";
  will display "FooBar", but still in the wrong position.
• Finally, I find it strange that the string is "Search" although I have set the language to something else (say, German).

Any help? The most pressing problem is to get the text to over the right.

回答1:

That behavior can be caused by overriding either (CGRect)editingRectForBounds:(CGRect)bounds or - (CGRect)textRectForBounds:(CGRect)bounds. Have you altered either of those in a UITextField category elsewhere in your app? The purpose of doing that may have been to add padding to a text field (which can instead be accomplished with an invisible leftView). In this case, your custom "padding" is being applied to the UISearchBar text field.

Such a category on UITextField will also cause your app to crash while initializing framework classes that use UITextField, such as MFMailComposeViewController, so it is a bad idea for several reasons.

来源：https://stackoverflow.com/questions/5526047/uisearchbar-display-bug-text-too-far-left-overlapping-the-magnifying-glass-ico