#pragma mark UITextField
比較蠢的一種方法
- (BOOL) textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
if (textField == _canPayMoneyTF) {
NSScanner? ? ? *scanner? ? = [NSScanner scannerWithString:string];
NSCharacterSet *numbers;
NSRange? ? ? ? pointRange = [textField.text rangeOfString:@"."];
if ( (pointRange.length > 0) && (pointRange.location < range.location? || pointRange.location > range.location + range.length) )
{
numbers = [NSCharacterSet characterSetWithCharactersInString:@"0123456789"];
}
else
{
numbers = [NSCharacterSet characterSetWithCharactersInString:@"0123456789."];
}
if ( [textField.text isEqualToString:@""] && [string isEqualToString:@"."] )
{
return NO;
}
short remain = 2; //默認(rèn)保留2位小數(shù)
NSString *tempStr = [textField.text stringByAppendingString:string];
NSUInteger strlen = [tempStr length];
if(pointRange.length > 0 && pointRange.location > 0){ //判斷輸入框內(nèi)是否含有“.”鼎姊。
if([string isEqualToString:@"."]){ //當(dāng)輸入框內(nèi)已經(jīng)含有“.”時(shí)澄者，如果再輸入“.”則被視為無效。
return NO;
}
if(strlen > 0 && (strlen - pointRange.location) > remain+1){ //當(dāng)輸入框內(nèi)已經(jīng)含有“.”衷戈，當(dāng)字符串長(zhǎng)度減去小數(shù)點(diǎn)前面的字符串長(zhǎng)度大于需要要保留的小數(shù)點(diǎn)位數(shù)，則視當(dāng)次輸入無效层坠。
return NO;
}
}
NSRange zeroRange = [textField.text rangeOfString:@"0"];
if(zeroRange.length == 1 && zeroRange.location == 0){ //判斷輸入框第一個(gè)字符是否為“0”
if(![string isEqualToString:@"0"] && ![string isEqualToString:@"."] && [textField.text length] == 1){ //當(dāng)輸入框只有一個(gè)字符并且字符為“0”時(shí)殖妇，再輸入不為“0”或者“.”的字符時(shí)，則將此輸入替換輸入框的這唯一字符破花。
textField.text = string;
return NO;
}else{
if(pointRange.length == 0 && pointRange.location > 0){ //當(dāng)輸入框第一個(gè)字符為“0”時(shí)谦趣，并且沒有“.”字符時(shí)，如果當(dāng)此輸入的字符為“0”座每，則視當(dāng)此輸入無效前鹅。
if([string isEqualToString:@"0"]){
return NO;
}
}
}
}
NSString *buffer;
if ( ![scanner scanCharactersFromSet:numbers intoString:&buffer] && ([string length] != 0) )
{
return NO;
}
}
return YES;
}
