我正在尝试使用带有三个组件的UIPickerView创建一个应用程序。第一个组件有3行。第二个组件有6行,第三个组件有12行。每次我在组件2或3中的第3行滚动时,应用程序崩溃并指向第一个组件数组。我确信这很容易解决,但我迷路了。提前谢谢。
-(void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row
inComponent:(NSInteger)component
{
{
NSString *resultString0 = [[NSString alloc] initWithFormat:
@"Sensor: %@",
[modelArray objectAtIndex:row]];
modelLabel.text = resultString0;
[resultString0 release];
}
{
NSString *resultString1 = [[NSString alloc] initWithFormat:
@"Pixels: %@",
[memoryArray objectAtIndex:row]];
memoryLabel.text = resultString1;
[resultString1 release];
NSString *firstString = horizFaceRecLabel.text;
float horizontalFace = [[horizontalArray objectAtIndex:row] floatValue];
float requiredFace = 100;
output1 = [firstString floatValue];
output1 = horizontalFace / requiredFace;
horizFaceRecLabel.text = [NSString stringWithFormat:(@"%.1f ft"), output1];
NSString *secondString = horizLicensePlateLabel.text;
float horizontalLicense = [[horizontalArray objectAtIndex:row] floatValue];
float requiredLicense = 45;
output2 = [secondString floatValue];
output2 = horizontalLicense / requiredLicense;
horizLicensePlateLabel.text = [NSString stringWithFormat:(@"%.1f ft"), output2];
NSString *thirdString = horizVisualIdLabel.text;
float horizontalVisual = [[horizontalArray objectAtIndex:row] floatValue];
float requiredVisual = 30;
output3 = [thirdString floatValue];
output3 = horizontalVisual / requiredVisual;
horizVisualIdLabel.text = [NSString stringWithFormat:(@"%.1f ft"), output3];
}
{
NSString *resultString2 = [[NSString alloc] initWithFormat:
@"Lens: %@",
[lensArray objectAtIndex:row]];
lensLabel.text = resultString2;
[resultString2 release];
{
NSString *firstDistString = faceRecLabel.text;
float angle = [[anglesArrayA objectAtIndex:row] floatValue];
float densityOne;
float densityTwo;
densityOne = [firstDistString floatValue];
densityTwo = (output1/2)/(sin(angle/2));
faceRecLabel.text = [NSString stringWithFormat:(@"%.1f ft"), densityTwo];
}
}
}
答案 0 :(得分:1)
看起来你缺少一些if
语句来控制何时调用每个代码块。
对于每个组件,您可能有三个单独的代码块,但由于没有条件来控制流,因此只要选择了任何组件中的行,就会执行所有块。 (第三个区块里面还有另一个区块 - 不知道为什么你这样编写它。)
当您超越第2和第3个组件中的第3行时,第1个组件的代码在尝试获取组件1的数组中的第4行(不存在)时运行并崩溃。
由于组件索引从零开始,因此条件应类似于:
if (component == 0)
{
//code for 1st component here...
}
else if (component == 1)
{
//code for 2nd component here...
}
else if (component == 2)
{
//code for 3rd component here...
}
您也可以使用switch
语句。