判断密码长度

//写一个label

self.label=[[UILabel
alloc] initWithFrame:CGRectMake(100,
50,
100, 30)];

self.label.layer.borderWidth=1;

self.label.backgroundColor=[UIColor
clearColor];
[self.window
addSubview:self.label];
[self.label
release];

self.label.text=@"";

//写一个textField

self.testField=[[UITextField
alloc] initWithFrame:CGRectMake(100,
200,
100, 30)];

[self.window
addSubview:self.testField];
[self.testField
release];

self.testField.layer.cornerRadius=10;

self.testField.layer.borderWidth=1;

只要输入就会执行length5方法

[self.testField
addTarget:self
action:@selector(length5:)
forControlEvents:UIControlEventEditingChanged];

-(void)length5:(UITextField *)textField
{

if (textField.text.length>5) {

self.label.text=@"密码长度不符合标准";
}

else{

self.label.text=@"密码长度符合标准";
}

}