Question

我在计算UIProgressView的进度时遇到问题。我的浮动值对进度没有影响。我试图手动设置进度它工作正常，但如果我尝试计算它它不起作用。

这是我的代码：

- (void) initProgressbar {

   self.progressView = [[UIProgressView alloc] initWithProgressViewStyle:UIProgressViewStyleDefault];
   [self.progressView setFrame:CGRectMake(0, 0, SCREEN_WIDTH / 2, 10)];
   self.progressView.center = CGPointMake(SCREEN_WIDTH - 110, SCREEN_HEIGHT - 25);
   self.progressView.progress = 0.0;
   [self.view addSubview:self.progressView];
}

nbElementsSync和nbElementsToSync是全局int属性，nbElementsSync在调用updateProgress方法之前循环递增。

MyController.h

@interface MyController : UIViewController {

   NSString *json;
   int nbElementsToSync;
   int nbElementsSync;

}

@property (nonatomic, strong) UIProgressView *progressView;

MyController.m

nbElementsSync = 0; // Nb elements synchronized
nbElementsToSync = [[json valueForKey:@"count"] intValue]; // Nb elements to synchronize

for (NSString* result in results) {

    nbElementsSync++;
    [self updateProgress];

}

这是我设置进度的方法：

- (void) updateProgress {

   [self.progressView setProgress:((float)nbElementsSync / nbElementsToSync)];
   NSLog(@"percent : %f", ((float)nbElementsSync / nbElementsToSync));

}

我的NSLog的结果：

percent : 0.003937
percent : 0.007874
percent : 0.011811
percent : 0.015748
percent : 0.019685
percent : 0.023622
...

有什么想法解决它吗？提前谢谢。

Answer 1

您是否尝试在后台进程中执行循环，而不是阻止UI更新：

<强> MyController.m

在需要的地方拨打电话：

[self performSelectorInBackground:@selector(syncInBackground) withObject:nil];

然后

- (void)syncInBackground
{
    int nbElementsSync = 0; // Nb elements synchronized
    int nbElementsToSync = [[json valueForKey:@"count"] intValue]; // Nb elements to synchronize

    for (NSString* result in results) {
        nbElementsSync++;

        float percent = (float)nbElementsSync / nbElementsToSync;

        [self performSelectorOnMainThread:@selector(updateProgress:) withObject:[NSNumber numberWithFloat:percent] waitUntilDone:NO];
    }   
}

- (void) updateProgress:(NSNumber *)percent {

    [self.progressView setProgress:percent.floatValue];
}

如何在UIProgressView中设置进度

1 个答案: