如何在 UIPickerView 中自动换行

Question

我有一个 UIPickerView，我想让文本自动换行。

这是我的代码：

- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view
{
    if (component == 0) {
    UILabel *lView = (UILabel *)view;

    if (!tView) {
        tView = [[UILabel alloc] init];
        [tView setFont:[UIFont systemFontOfSize:15]];
        tView.numberOfLines = [categorie count];
    }
    tView.text = [categorie objectAtIndex:row];
    return tView;
    }
    else {
        UILabel *lView = (UILabel *)view;

        if (!sView) {
            sView = [[UILabel alloc] init];
            [sView setFont:[UIFont systemFontOfSize:15]];
            sView.numberOfLines = [subCat count];
        }
        sView.text = [subCat objectAtIndex:row];
        return sView;
    }
}

我尝试设置 sView.numberOfLines = 0; （这就是您通常将 UILabel 设置为自动换行或超过 1 行的方式）但这不起作用。

Answer 1

让我解释一下您的代码中发生了什么，例如让我们想象一下，subCat 数组包含两个字符串对象：“one”、“two”

// You try to reuse label for picker
UILabel *sView = (UILabel *)view;
if (!sView) {
    // if this view doesn't exists, you create new label
    sView = [[UILabel alloc] init];
    [sView setFont:[UIFont systemFontOfSize:15]];
    // And once set numberOfLines to value 2 in our case
    sView.numberOfLines = [subCat count];
}
// And here you set text to "one" or "two" value from array
// I don't understand where you set multiline text value?
sView.text = [subCat objectAtIndex:row];
return sView;

你需要这样的东西：

sView.text = [subCat componentsJoinedByString:@"\n"];