我尝试了以下在 Obj-C 中有效的方法，但我在 swift 中遇到了错误: '(@lvalue UIPickerView!, titleForRow: Int, forComponent: Int) -> $T7' 与 'UIPickerView' 不相同
func pickerView(pickerView: UIPickerView, viewForRow row: Int, forComponent component: Int, reusingView view: UIView!) -> UIView
{
var pickerLabel = UILabel()
pickerLabel.textColor = UIColor.whiteColor()
pickerLabel.text = pickerView(pickerView, titleForRow: row, forComponent: component)
return pickerLabel
}
这是 obj-c 的工作代码:
- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view{
UILabel* pickerLabel = (UILabel*)view;
if (!pickerLabel){
pickerLabel = [[UILabel alloc] init];
[pickerLabel setFont:[UIFont fontWithName:@"Helvetica Neue Bold Italic" size:25]];
}
pickerLabel.textAlignment = NSTextAlignmentCenter;
pickerLabel.textColor = [UIColor whiteColor];
pickerLabel.text=[self pickerView:pickerView titleForRow:row forComponent:component];
return pickerLabel;
}
- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component {
if (component == 0){
if ([unitType isEqualToString:@"MS"]) {
return [thickness objectAtIndex:row];
}else{
NSString *th = [thickness objectAtIndex:row];
float tt = [th floatValue]*0.039370078740157;
NSString *new_th = [NSString stringWithFormat:@"%2.2f",tt];
return new_th;
}
}
if(component ==1){
if ([unitType isEqualToString:@"MS"]) {
return [weight_data objectAtIndex:row];
}else{
NSString *wei = [weight_data objectAtIndex:row];
float ww = [wei floatValue]*2.205;
NSString *new_wei = [NSString stringWithFormat:@"%3.1f",ww];
return new_wei;
}
}
最佳答案
我认为你想打印从 UIPickerView 中选择索引的数据，但我认为你这样做是错误的。
这是给你的几个例子:
var states : [String]!
func pickerView(pickerView: UIPickerView, viewForRow row: Int,
forComponent component: Int, reusingView view: UIView!) -> UIView {
var lab : UILabel
if let label = view as? UILabel {
lab = label
println("reusing label")
} else {
lab = MyLabel()
println("making new label")
}
// You can set text this way where states is an array of string.
lab.text = self.states[row]
lab.backgroundColor = UIColor.clearColor()
lab.sizeToFit()
return lab
}
}
引用自 HERE
另一个例子是:
func pickerView(pickerView: UIPickerView, viewForRow row: Int, forComponent component: Int, reusingView view: UIView!) -> UIView {
var pickerLabel = view as UILabel!
if view == nil { //if no label there yet
pickerLabel = UILabel()
//color the label's background
let hue = CGFloat(row)/CGFloat(pickerData.count)
pickerLabel.backgroundColor = UIColor(hue: hue, saturation: 1.0, brightness: 1.0, alpha: 1.0)
}
let titleData = pickerData[row]
let myTitle = NSAttributedString(string: titleData, attributes: [NSFontAttributeName:UIFont(name: "Georgia", size: 26.0)!,NSForegroundColorAttributeName:UIColor.blackColor()])
//This way you can set text for your label.
pickerLabel!.attributedText = myTitle
return pickerLabel
}
引用自HERE .
希望对您有所帮助。
关于swift:与 ‘UIPickerView’ 不同，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/27456061/