问题
i want to get a cursor position from UITextview, i have implement the code in How to find a pixel-positon of a cursor in UITextView? post, the algorithm is based on algorithm in Pixel-Position of Cursor in UITextView.
my problem is, i can't get the selectedRange.location value after keyboard appear in the 2nd time, cause it always tell that the value of location is 2147483647, which means not found. This is my implementation :
-(void)getCursorPosition{
NSRange originalPosition = self.codeTextView.selectedRange;
NSLog(@"original position : %d", self.codeTextView.selectedRange.location);
CGPoint origin = self.codeTextView.frame.origin;
unichar c = ' ';
NSLog(@"location : %d", self.codeTextView.selectedRange.location);
NSLog(@"length : %d", self.codeTextView.selectedRange.length);
if (self.codeTextView.selectedRange.location != [self.codeTextView.text length]) {
// NSLog(@"cek 1");
c = [self.codeTextView.text characterAtIndex:self.codeTextView.selectedRange.location];
// NSLog(@"cek 2");
}
NSLog(@"c : %d", c);
if (c!=32 && c!=10) {
NSRange delimiter = [self.codeTextView.text rangeOfCharacterFromSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]
options:NSLiteralSearch
range:NSMakeRange(self.codeTextView.selectedRange.location,
[self.codeTextView.text length] - self.codeTextView.selectedRange.location)];
if (delimiter.location == NSNotFound) {
delimiter.location = [self.codeTextView.text length];
}
self.codeTextView.selectedRange = delimiter;
NSLog(@"delimiter length : %d, location : %d", delimiter.length, delimiter.location);
}
int deviationLocation = self.codeTextView.selectedRange.location - originalPosition.location;
NSString *head = [self.codeTextView.text substringToIndex:self.codeTextView.selectedRange.location];
CGSize initialSize = [head sizeWithFont:self.codeTextView.font constrainedToSize:CGSizeMake(self.codeTextView.frame.size.width,
self.codeTextView.frame.size.height)];
NSUInteger startOfLine = [head length];
BOOL isFirstLine = NO;
NSLog(@"initialize height : %f", initialSize.height);
NSLog(@"code height : %f", self.codeTextView.contentSize.height);
if (initialSize.height / self.codeTextView.contentSize.height == 1) {
isFirstLine = YES;
}
while (startOfLine > 0 && isFirstLine == NO) {
NSRange delimiter = [head rangeOfCharacterFromSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]
options:NSBackwardsSearch range:NSMakeRange(0, startOfLine)];
startOfLine = delimiter.location;
NSString *tempHead = [head substringToIndex:startOfLine];
CGSize tempHeadSize = [tempHead sizeWithFont:self.codeTextView.font constrainedToSize:CGSizeMake(self.codeTextView.frame.size.width,
self.codeTextView.frame.size.width)];
int beforeLine = initialSize.height / self.codeTextView.contentSize.height;
int afterLine = tempHeadSize.height / self.codeTextView.contentSize.height;
if (beforeLine != afterLine)
NSLog(@"break");
break;
}
NSString *tail;
if (isFirstLine == NO) {
tail = [head substringFromIndex:(startOfLine + deviationLocation)];
}else {
tail = [head substringToIndex:startOfLine - deviationLocation];
}
CGSize lineSize = [tail sizeWithFont:self.codeTextView.font forWidth:self.codeTextView.frame.size.width lineBreakMode:UILineBreakModeWordWrap];
cursor = origin;
cursor.x += lineSize.width;
cursor.y += initialSize.height - lineSize.height;
self.codeTextView.selectedRange = originalPosition;
[self.codeTextView becomeFirstResponder];
NSLog(@"cursor x : %f, y : %f", cursor.x, cursor.y);
}
i called that method in textViewShouldBeginEditing method, this is the implementation :
-(BOOL)textViewShouldBeginEditing:(UITextView *)textView{
[self getCursorPosition];
self.viewTextViewScroll.contentSize = CGSizeMake(self.codeTextView.frame.size.width, self.codeTextView.contentSize.height+100);
CGRect frameCode = self.codeTextView.frame;
frameCode.size.height = self.codeTextView.contentSize.height + 103;
self.codeTextView.frame = frameCode;
CGRect frameLine = self.lineNumberTextView.frame;
frameLine.size.height = self.codeTextView.contentSize.height +100;
self.lineNumberTextView.frame = frameLine;
return YES;
}
can somebody help me, please
UPDATE :
i have solved this problem, with using textViewDidChangeSelection delegate method, here is the code i've made :
-(void)textViewDidChangeSelection:(UITextView *)textView{
counterAppear++;
if (counterAppear == 1) {
}
else if (counterAppear == 2) {
isFistAppear = NO;
codeBuilderSelectedRange = textView.selectedRange;
[self getCursorPosition];
CGFloat xPos = cursor.x - (0.5*self.view.frame.size.width);
if (cursor.x < self.view.frame.size.width) {
[[[self.viewCodeTextView subviews] lastObject] setContentOffset:CGPointMake(0, cursor.y) animated:YES];
}else {
[[[self.viewCodeTextView subviews] lastObject] setContentOffset:CGPointMake(xPos, cursor.y) animated:YES];
}
}else if (isFistAppear == NO) { //kondisi saat keyboard masih appear & user pindah2 kursor
codeBuilderSelectedRange = textView.selectedRange;
[self getCursorPosition];
NSLog(@"cursor x :%f, y : %f", cursor.x, cursor.y);
}
}
i set the BOOL isFirstAppear in viewDidLoad, i set this because, after i nslog the selectedRange.location value in textViewDidChangeSelection, it always called twice, the first value always give a not found value, but the second give a right value, so i set like that. The counterAppear i set in keyboard method (i made a method that called by NSNotification in viewDidLoad). counterAppear is the value that give me the difference condition when i tap the textview.
回答1:
In textViewDidBeginEditing, the location value will wrong sometimes. To fix this, do this:
-(void)textViewDidBeginEditing:(UITextView *)textView {
[self performSelector:@selector(beginEditing:) withObject:textView afterDelay:0]; }-(void)beginEditing:(UITextView*)sender {
//code here }
来源：https://stackoverflow.com/questions/4613978/how-can-i-get-selectedrange-location-value