iOS 提升交互之根据多个UITextField的编辑状态改变按钮状态

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

- (BOOL)getButtonEnableByCurrentTF:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string tfArr:(NSArray *)tfArr;{
if (string.length) {// 文本增加
NSMutableArray *newTFs = [NSMutableArray arrayWithArray:tfArr];
[newTFs removeObject:textField];
for (UITextField *tempTF in newTFs) {
if (tempTF.text.length==0) return NO;
}
}else{// 文本删除
if (textField.text.length-range.length==0) {// 当前TF文本被删完
return NO;
}else{
NSMutableArray *newTFs = [NSMutableArray arrayWithArray:tfArr];
[newTFs removeObject:textField];
for (UITextField *tempTF in newTFs) {
if (tempTF.text.length==0) return NO;
}
}
}
return YES;
}

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
// 提升交互:动态设置按钮可行不可行
NSArray *tfs = @[_accountTF, _pswTF];

if ([self getButtonEnableByCurrentTF:textField shouldChangeCharactersInRange:range replacementString:string tfArr:tfs]) {
[_loginButton changeStyleToStandard];// 置为可用
}else{
[_loginButton ZS_standardDisable];// 置为不可用
}
return YES;
}