【学习ios之路:UI系列】UIProgressView

实现类似读取数据进度条效果

代码如下:
①创建UIProgressView对象
1)定义属性

{
    NSTimer *_proTimer;//计时   
}
@property (nonatomic, retain) UIProgressView *proView;
//显示进度信息
@property (nonatomic, retain) UILabel *proLabel;
@property (nonatomic, assign) float proValue;//保存进度值

  //创建控件UIProgressView
    self.proView = [[UIProgressView alloc] initWithProgressViewStyle:UIProgressViewStyleDefault];

    //设置frame
    self.proView.frame = CGRectMake(10, 260, 300, 100); 
    //设置当前进度当前值
    self.proView.progress = 0;
   // self.proValue = 0.4;
    //设置进度条的颜色
    self.proView.progressTintColor = [UIColor orangeColor];
    //导轨的颜色
    self.proView.trackTintColor = [UIColor greenColor];
    //修改进度条的高度(仿射变换)
    self.proView.transform = CGAffineTransformMakeScale(1.0f,15.0f);
    //添加到当前的试图上
    [self.view addSubview:self.proView];
    //释放
    [self.proView release];

②设置Label显示进度值,

    //创建显示进度信息的label
    self.proLabel = [[UILabel alloc] initWithFrame:CGRectMake(100, 300, 120, 30)];
    self.proLabel.backgroundColor = [UIColor clearColor];

    //显示当前进度值
    self.proLabel.text = [NSString stringWithFormat:@"loading%1.f%%",self.proView.progress*100];
    [self.view addSubview:self.proLabel];
    [self.proLabel release];

③创建计时器,平处理事件

    //通过计时器循环改进度值
    _proTimer = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(changeProgress) userInfo:nil repeats:YES];

//处理事件
- (void)changeProgress {
    //设置进度每次变化值
    self.proValue += 0.05;
    self.proView.progress = self.proValue;
    //显示实时的进度值
    self.proLabel.text = [NSString stringWithFormat:@"loading%1.f%%",self.proValue * 100];
    if (self.proValue >= 1) {
        self.proValue = 0;  
        self.proLabel.text = @"进度完成";
        //停止计数器
        [_proTimer invalidate];
    }


}