UIPickerView 的简单应用

Posted 2020-07-11

首先  想应用PickerView 要引入两个代理 

UIPickerViewDelegate,UIPickerViewDataSource

然后  我们在.m里面建立 UIPickerView

由于默认pickerView 只有一个滚轮   所以 想要自定义PickerView  是在一个UIView上面添加 pickerView 放在下面  然后在View的其他地方放Button什么之类的

 

 

 UIView *pickerView=[[UIView alloc]initWithFrame:CGRectMake(0.0, [UIScreen mainScreen].bounds.size.height, [UIScreen mainScreen].bounds.size.width, 226.0*SCREEN_HEIGHT/568)];

    pickerView.backgroundColor=selfGrayColor;

    self.pickerBackView =pickerView;

    //添加View

    UIButton *finshButton=[[UIButton alloc]initWithFrame:CGRectMake([UIScreen mainScreen].bounds.size.width-60, 0.0, 50.0, 40)];

    [finshButton setTitle:@"完成" forState:UIControlStateNormal];

    [finshButton setTitleColor:selfBlueColor forState:UIControlStateNormal];

    finshButton.layer.cornerRadius=10;

    [finshButton addTarget:self action:@selector(tapActionClick1:) forControlEvents:UIControlEventTouchUpInside];

    [self.pickerBackView addSubview:finshButton];

    

    UIButton *disButton=[[UIButton alloc]initWithFrame:CGRectMake(10.0, 0.0, 50.0, 40)];

    [disButton setTitle:@"取消" forState:UIControlStateNormal];

    [disButton setTitleColor:selfBlueColor forState:UIControlStateNormal];

    disButton.layer.cornerRadius=10;

    [disButton addTarget:self action:@selector(tapActionClick1:) forControlEvents:UIControlEventTouchUpInside];

    [self.pickerBackView addSubview:disButton];

    //View上添加Button

    self.pickerView = [[UIPickerView alloc]initWithFrame:CGRectMake(0.0,40.0, [UIScreen mainScreen].bounds.size.width, self.pickerBackView.frame.size.height-60)];

    self.pickerView.delegate = self;

    self.pickerView.dataSource = self;

    self.pickerView.backgroundColor = [UIColor whiteColor];

    [self.pickerBackView addSubview:self.pickerView];//pickerView添加到View上

    [self.view addSubview:self.pickerBackView];

 

然后是pickerView的代理  跟TableView的代理很像  基本都一样  

//多少列

-(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView

{

return 2;//即有两个滚轮 

}

//多少行

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

{

　　//component 可以看成tableView的section

　　return 10;//每个滚轮有10行  如果不一样的行数  判断component 值 分别return就OK了

}

//自定义 每一个行样子

- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view{

    UILabel* pickerLabel = (UILabel*)view;

    if (!pickerLabel){

        pickerLabel = [[UILabel alloc] init];

        // Setup label properties - frame, font, colors etc

        //adjustsFontSizeToFitWidth property to YES

        pickerLabel.adjustsFontSizeToFitWidth = YES;

        [pickerLabel setTextAlignment:NSTextAlignmentCenter];

        [pickerLabel setBackgroundColor:[UIColor clearColor]];

        [pickerLabel setFont:[UIFont systemFontOfSize:13]];

    }

    pickerLabel.text=[self pickerView:pickerView titleForRow:row forComponent:component];

    return pickerLabel;

}

//每行显示的内容

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

{

　　可以看成cell的处理方法  但是 因为pickerView只有title所以   返回的只有字符串就OK了

　　return string；

}

 

 //滑动触发的方法

- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component

　{   //这个是每一次滑动都会触发这个方法   但注意 如果只是打开pickerView  不会调用   只有滑动了之后才会触发  所以如果要处理第一次的默认传值 要自己注意

 

}

 

//动画   放在要调用pickerView的地方就行了   会从西面自动弹出   根据需求不同  随意更改

 //弹出pickerView的简单动画

        [UIView beginAnimations:nil context:nil];

        [UIView setAnimationDuration:0.5];

        

        self.pickerBackView.frame = CGRectMake(0.0, [UIScreen mainScreen].bounds.size.height-(256*SCREEN_HEIGHT/568), [UIScreen mainScreen].bounds.size.width, 256*SCREEN_HEIGHT/568);

        [UIView commitAnimations];

        [self.pickerView selectRow:0 inComponent:0 animated:NO];

 

//回收键盘

   [UIView beginAnimations:nil context:nil];

    [UIView setAnimationDuration:0.5];

    self.pickerBackView.frame = CGRectMake(0.0, [UIScreen mainScreen].bounds.size.height, [UIScreen mainScreen].bounds.size.width, 226*SCREEN_HEIGHT/568);

    [UIView commitAnimations];

没时间了 有时间详写