如何创建五个带有标签的 UIPickerView？以及如何在 iPhone 中为每个 UIPickerView 赋予不同的名称？答案

【问题标题】：How to cretae five UIPickerView with tag? And how to give different name to every UIPickerView, in iPhone?如何创建五个带有标签的 UIPickerView？以及如何在 iPhone 中为每个 UIPickerView 赋予不同的名称？
【发布时间】：2013-02-20 09:00:25
【问题描述】：

我现在有 2 个 UIPickerView，以后想再添加三个。代码如下：

-(void)viewDidLoad{
Pos_x = 5;
Pos_y = 70;

for (i= 0; i<2; i++) {

myPickerView = [[UIPickerView alloc] init];
myPickerView.frame = CGRectMake(Pos_x,Pos_y,150,300);
myPickerView.tag = i;
myPickerView.delegate = self;
myPickerView.showsSelectionIndicator = YES;
[self.view addSubview:myPickerView];

if (i==0) {
// Init the data array.
Array_1 = [[NSMutableArray alloc] init];

// Add some data for demo purposes.
[Array_1 addObject:@"One"];
[Array_1 addObject:@"Two"];
[Array_1 addObject:@"Three"];
[Array_1 addObject:@"Four"];
[Array_1 addObject:@"Five"];
}

if (i==1) {

Array_2 = [[NSMutableArray alloc] init];

// Add some data for demo purposes.
[Array_2 addObject:@"One1"];
[Array_2 addObject:@"Two1"];
[Array_2 addObject:@"Three1"];
[Array_2 addObject:@"Four1"];
[Array_2 addObject:@"Five1"];  
}

Pos_x = Pos_x + 162;
}
}

我已经成功创建了两个带有标签的 UIPickerView。现在的问题是在 UIPickerView 中添加数据。

我就是这样的

- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component {

//return [Array_1 objectAtIndex: row];  // If give only this line both UIPickerView show same value.

//How to show both 
//return [Array_2 objectAtIndex: row]; 

// I also tried this code

if(pickerView == myPickerView){

 if (i==0){
 }
 return [Array_1 objectAtIndex: row];
 }

 if (i==1){
 }
 return [Array_2 objectAtIndex: row];
 }


}

现在我的问题是如何在两个 UIPickerView 上显示不同的不同数据？就像在 pickerview.tag ==0 上一样，它会显示 return [Array_1 objectAtIndex: row]; 并且 pickerview.tag ==1 它会显示 return [Array_2 objectAtIndex: row];？欢迎任何想法或建议。

【问题讨论】：

你应该去if(pickerView.tag == 0)而不是if(i==0)
我已经这样做了，但还不错。
我的意思是在 titleForRow 方法中，你去if(i==0) 那里没有意义，因为i 甚至没有定义.. 除非你省略一些代码

标签： iphone ios objective-c xcode uipickerview

【解决方案1】：

请检查此代码：

-(void)viewDidLoad{
myPickerView = [[UIPickerView alloc] init];
myPickerView.frame = CGRectMake(5,70,150,300);
//myPickerView.tag = i;
myPickerView.delegate = self;
myPickerView.showsSelectionIndicator = YES;
[self.view addSubview:myPickerView];

Array_1 = [[NSMutableArray alloc] init];

// Add some data for demo purposes.
[Array_1 addObject:@"One"];
[Array_1 addObject:@"Two"];
[Array_1 addObject:@"Three"];
[Array_1 addObject:@"Four"];
[Array_1 addObject:@"Five"];
[Array_1 addObject:@"Six"];


myPickerView_2nd = [[UIPickerView alloc] init];
myPickerView_2nd.frame = CGRectMake(167,70,150,300);
//myPickerView_2nd.tag = i;
myPickerView_2nd.delegate = self;
myPickerView_2nd.showsSelectionIndicator = YES;
[self.view addSubview:myPickerView_2nd];

Array_2 = [[NSMutableArray alloc] init];

// Add some data for demo purposes.
[Array_2 addObject:@"One1"];
[Array_2 addObject:@"Two1"];
[Array_2 addObject:@"Three1"];
[Array_2 addObject:@"Four1"];
[Array_2 addObject:@"Five1"];
[Array_2 addObject:@"Six1"];

}


- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView{
if([pickerView isEqual: myPickerView]){
// return the appropriate number of components, for instance
return 1;
}

if([pickerView isEqual: myPickerView_2nd]){
// return the appropriate number of components, for instance
return 1;
}
else 
return 0;
}

- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent: (NSInteger)component {


if ( pickerView == myPickerView) // this is otherPickerview
{
    return [Array_1 count];


}
if ( pickerView == myPickerView_2nd){
    return [Array_2 count];


}
else{
     NSUInteger numRows = 5;
    return numRows;}

}

希望对您有所帮助...

【讨论】：

【解决方案2】：

您可以使用数组或字典来存储内容数组并通过选择器的标签获取它们。例如。

NSArray *contentArrays = [[NSArray alloc] initWithObjects:Array_1, Array_2, nil];

然后用[contentArrays objectAtIndex:pickerView.tag];获取内容数组

【讨论】：

【解决方案3】：

你可以通过设置pickerview的标签来实现：

- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger) { 
    if(pickerView.tag == 1)
     {
          // do something with picker one
     }
     else if(pickerView.tag == 2)
     {
          // the other picker
     }
}

否则：

   - (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger) { 
        switch(pickerView.tag){
           case 1:
               //do something
               break;
           case 2:
               //do other thing
               break;
           default:
               break;
        }
    }

希望这会有所帮助..

也看看这个：Multiple PickerViews in one View?

【讨论】：