输入价格的格式判断

@property (nonatomic, assign) BOOL isHaveDian;

@property (nonatomic, assign) BOOL isFirstZero;

@property (nonatomic, strong) UITextField* startText;

遵循UITextField协议，并实现shouldChangeCharactersInRange方法

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {

if (textField ==self.startText) {

return [self panDuanTextField:textField  shouldChangeCharactersInRange:range replacementString:string];

}

}

return YES;

}

-(BOOL)panDuanTextField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {

if ([textField.text rangeOfString:@"."].location==NSNotFound) {

_isHaveDian = NO;

}

if ([textField.text rangeOfString:@"0"].location==NSNotFound) {

_isFirstZero = NO;

}

if ([string length]>0)

{

unichar single=[string characterAtIndex:0];//当前输入的字符

if ((single >='0' && single<='9') || single=='.')//数据格式正确

{

if([textField.text length]==0){

if(single == '.'){

//首字母不能为小数点

return NO;

}

if (single == '0') {

_isFirstZero = YES;

return YES;

}

}

if (single=='.'){

if(!_isHaveDian)//text中还没有小数点

{

_isHaveDian=YES;

return YES;

}else{

return NO;

}

}else if(single=='0'){

if ((_isFirstZero&&_isHaveDian)||(!_isFirstZero&&_isHaveDian)) {

//首位有0有.（0.01）或首位没0有.（10200.00）可输入两位数的0

if([textField.text isEqualToString:@"0.0"]){

return NO;

}

NSRange ran=[textField.text rangeOfString:@"."];

int tt=(int)(range.location-ran.location);

if (tt <= 2){

return YES;

}else{

return NO;

}

}else if (_isFirstZero&&!_isHaveDian){

//首位有0没.不能再输入0

return NO;

}else{

return YES;

}

}else{

if (_isHaveDian){

//存在小数点，保留两位小数

NSRange ran=[textField.text rangeOfString:@"."];

int tt= (int)(range.location-ran.location);

if (tt <= 2){

return YES;

}else{

return NO;

}

}else if(_isFirstZero&&!_isHaveDian){

//首位有0没点

return NO;

}else{

return YES;

}

}

}else{

//输入的数据格式不正确

return NO;

}

}else{

return YES;

}

return YES;

}