最近仿照支付寶登入根據賬號密碼TextField編輯狀態改變登入按鈕狀態的效果封裝了一個方法. 在UITextFieldDelegate的

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

方法中呼叫即可達到想要的效果:

封裝的程式碼:

- (BOOL)getButtonEnableByCurrentTF:(UITextField *)textField shouldChangeCharactersInRange:(NSRange
 
)range replacementString:(NSString *)string tfArr:(NSArray *)tfArr;{
    if (string.length) {// 文字增加
        NSMutableArray *newTFs = [NSMutableArray arrayWithArray:tfArr];
        [newTFs removeObject:textField];
        for (UITextField *tempTF in newTFs) {
            if (tempTF.text.length==0) return
 
 NO;
        }
    }else{// 文字刪除
        if (textField.text.length-range.length==0) {// 當前TF文字被刪完
            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;
}

呼叫例項:

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
    // 提升互動:動態設定按鈕可行不可行
    NSArray *tfs = @[_accountTF, _pswTF];

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