Question

现在，当我移动滑块时，我的文本字段的值正在改变。我还需要向后工作，改变文本字段值，滑块移动。

我的代码：

- (void)sliderChanged:(UISlider *)sender {

    self.slider.valueChangedHandler = ^(id sender) {
    self.aleField.text = [NSString stringWithFormat:@"%.f", [(UISlider *)sender value]];
};

}

修改

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
   slider.value = [aleField.text floatValue];

    NSUInteger newLength = [aleField.text length] + [string length] - range.length;
    return (newLength > 2) ? NO : YES;

}

Answer 1

创建文本字段后，添加：

[self.textField addTarget:self action:@selector(textFieldDidChange:) forControlEvents:UIControlEventEditingChanged];

然后有以下方法：

- (void)textFieldDidChange:(UITextField*)sender {
    //Assuming slider is a property
    slider.value = [sender.text floatValue];
}

我引用了https://stackoverflow.com/a/7010676/391040和https://stackoverflow.com/a/4711136/391040。

Answer 2

要在键入时执行此操作，请实现文本字段委托

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
    NSCharacterSet *numberSet = [[NSCharacterSet characterSetWithCharactersInString:@"0123456789"] invertedSet];
    NSString *filtered = [[string componentsSeparatedByCharactersInSet:numberSet] componentsJoinedByString:@""];
    BOOL basicTest = [string isEqualToString:filtered];
    if (basicTest) {
        slider.value = [aleField.text floatValue];
    }
    return basicTest;
}

这也允许您让用户只插入数字。

要将值反映到滑块：

slider.value = [textField.text floatValue];

文本字段更改后如何移动滑块？

2 个答案: