iOS 解決表單被鍵盤遮住的問題，ios表單鍵盤遮住
問題
處理表單的時候,一定會碰到的就是輸入控制項被鍵盤遮住的問題,:
執行個體
左邊是普通表單,中間是2B表單,右邊是文藝表單.
分析
處理這種問題無非就是2個步驟:
代碼寫出來就是這幾步
那麼如何一步一步的來實現這些步驟呢?
捕獲鍵盤事件
捕獲鍵盤事件
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[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(actionKeyboardShow:)
name:UIKeyboardDidShowNotification
object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(actionKeyboardHide:)
name:UIKeyboardWillHideNotification
object:nil];
- (void)actionKeyboardShow:(NSNotification *)notification
{
[[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardDidShowNotification object:nil];
[[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardDidChangeFrameNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(actionKeyboardShow:)
name:UIKeyboardDidChangeFrameNotification
object:nil];
}
- (void)actionKeyboardHide:(NSNotification *)notification
{
[[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardDidChangeFrameNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(actionKeyboardShow:)
name:UIKeyboardDidShowNotification
object:nil];
}
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計算鍵盤高度並調整
UITableView的
frame
計算鍵盤高度並調整UITableView的frame
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- (void)actionKeyboardShow:(NSNotification *)notification
{
CGSize keyboardSize = [[[notification userInfo] objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue].size
self.tableView.frame = CGRectMake(0, 0, 320, self.view.h-keyboardSize.height);
[[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardDidShowNotification object:nil];
[[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardDidChangeFrameNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(actionKeyboardShow:)
name:UIKeyboardDidChangeFrameNotification
object:nil];
}
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擷取當前正在輸入的控制項
這裡得說一句,普通程式員一般是這樣來擷取的
UIView的Category
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- (UIView *) getFirstResponder
{
if (self.isFirstResponder) {
return self;
}
for (UIView *subView in self.subviews) {
UIView *firstResponder = [subView getFirstResponder];
if (firstResponder != nil) {
return firstResponder;
}
}
return nil;
}
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雖然沒錯,但是文藝程式員應該這樣來擷取
UIResponder的Category
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static __weak id currentFirstResponder;
+(id)currentFirstResponder {
currentFirstResponder = nil;
[[UIApplication sharedApplication] sendAction:@selector(findFirstResponder:) to:nil from:nil forEvent:nil];
return currentFirstResponder;
}
-(void)findFirstResponder:(id)sender {
currentFirstResponder = self;
}
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同理,有時候我們需要讓鍵盤消失,那麼也有三種做法可以選擇
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[someView resignFirstResponder];
[self.view endEditing:YES];
[[UIApplication sharedApplication] sendAction:@selector(resignFirstResponder) to:nil from:nil forEvent:nil];
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如何選擇呢? It’s up to U.
計算其在
UITableView中的位置,並滾動到其位置讓其可見
計算其在UITableView中的位置,並滾動到其位置讓其可見
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- (void)actionKeyboardShow:(NSNotification *)notification
{
CGSize keyboardSize = [[[notification userInfo] objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue].size;
self.tableView.frame = CGRectMake(0, 0, 320, self.view.h-keyboardSize.height);
UIView *v = [UIResponder currentFirstResponder];
if ( v )
{
while ( ![v isKindOfClass:[UITableViewCell class]]) {
v = v.superview;
}
UITableViewCell *cell = (UITableViewCell*)v;
[self.tableView scrollToRowAtIndexPath:[self.tableView indexPathForRowAtPoint:cell.center] atScrollPosition:UITableViewScrollPositionBottom animated:YES];
}
[[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardDidShowNotification object:nil];
[[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardDidChangeFrameNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(actionKeyboardShow:)
name:UIKeyboardDidChangeFrameNotification
object:nil];
} |
