在NSMutableArray的末端插入元素

Question

我從Web服務加載數組並在拾取器中顯示它們，並且所有工作都正常。我的數組包含每個問題類別的隨機數量的問題。現在我想要的是，我想添加一個更多的條目「你自己的問題」在數組的末尾，以便選擇器的最後一行顯示「你自己的問題」。我該怎麼做

- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view { 
    UILabel *retval = (id)view; 
    if (!retval) { 
     retval= [[UILabel alloc] initWithFrame:CGRectMake(0.0f, 0.0f, [pickerView rowSizeForComponent:component].width, [pickerView rowSizeForComponent:component].height)]; 
    } 

    // retval.text = [idAndNameArray objectAtIndex:row]; 
    if([pickerType isEqualToString:@"picker"]) 
    { 
     retval.text = [idAndNameArray objectAtIndex:row]; 
    } 
    else 
    { 
     retval.text = [quesArray objectAtIndex:row]; 
    } 
    retval.font = [UIFont boldSystemFontOfSize:14]; 
    retval.numberOfLines = 3; 
    return retval; 
} 

此代碼只顯示從Web服務中獲取的行數（問題）。

編輯1：

- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)thePickerView 
{ 

    return 1; 
} 

- (NSInteger)pickerView:(UIPickerView *)thePickerView numberOfRowsInComponent:(NSInteger)component 
{ 
    if([pickerType isEqualToString:@"picker"]) 
    { 
     return [idAndNameArray count]; 
    } 
    else 
    { 
     return [quesArray count]; 
    } 

} 

編輯2：

通過使另一NSMutableArray裏與我的自定義對象 「自己的問題」，然後與陣列從Web服務獲取其附加解決

NSMutableArray *customObj = [NSMutableArray arrayWithObject: @"test"]; 
[quesArray addObjectsFromArray:customObj]; 

Answer 1

在UIPickerViewDataSource的方法calle d pickerView:numberOfRowsInComponent:返回您的數組的計數加上一個值（return arr.count+1;），並在您已實施的UIPickerVIewDelegate的方法中，當component大於arr.count-1（if(row>(arr-1)){//return the label with 'Your own question'}）時，將文本返回給您的標籤。祝你好運！

編輯：

- (NSInteger)pickerView:(UIPickerView *)thePickerView numberOfRowsInComponent:(NSInteger)component 
{ 
    if([pickerType isEqualToString:@"picker"]) 
    { 
     return [idAndNameArray count]; 
    } 
    else 
    { 
     return [quesArray count]+1; 
    } 

} 
- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view { 
    UILabel *retval = (id)view; 
    if (!retval) { 
     retval= [[UILabel alloc] initWithFrame:CGRectMake(0.0f, 0.0f, [pickerView rowSizeForComponent:component].width, [pickerView rowSizeForComponent:component].height)]; 
    } 

    // retval.text = [idAndNameArray objectAtIndex:row]; 
    if([pickerType isEqualToString:@"picker"]) 
    { 
     retval.text = [idAndNameArray objectAtIndex:row]; 
    } 
    else 
    { 
     if(row>quesArray.count-1){ 
     retval.text = @"You own question"; 
     } 
     else{ 
      retval.text = [quesArray objectAtIndex:row]; 
     } 
     } 
     retval.font = [UIFont boldSystemFontOfSize:14]; 
     retval.numberOfLines = 3; 
     return retval; 
    }