如何在iOS4中使用UISlider从Setting.bundle设置UIScreen亮度 [英] How to set UIScreen Brightness Using UISlider in iOS4 from Setting.bundle

问题描述

我正在设置一个设置主屏幕亮度的功能
i搜索大量googling得到一个代码。

I am working one Feature of setting Brightness of mainscreen i search lots of googling got one code.

UISlider *slider = (UISlider *)sender;
float fBrightness = slider.value;
[[UIScreen mainScreen]setBrightness:fBrightness];

但是当我在我的应用程序中使用此代码时，此代码仅适用于iOS5而不是iOS4警告和我的应用程序崩溃

But this code is worked Only iOS5 not in iOS4 when i am using this code in my apps i got warning and my app crash

 warning: 'UIScreen' may not respond to '-setBrightness:'

所以请任何人帮我如何在iOS4中恭维这个功能
谢谢

so please anyone help me how to empliments this feature in iOS4 thank you

-(解决方案）

-(void)ActionBrightness{


    NSUserDefaults *defaults2 = [NSUserDefaults standardUserDefaults];    //slidervalue from setting.bundle
    float values = [defaults2 floatForKey:@"slider_preference"];
    NSLog(@"value of slider %f",values);

    //if(polygonView == nil){
    polygonView = [[UIView alloc] initWithFrame: CGRectMake ( 0, 0, 500, 500)];

    //add code to customize, e.g. polygonView.backgroundColor = [UIColor blackColor];
    polygonView.userInteractionEnabled  = NO;

    if(values < 0.1){
        polygonView.backgroundColor = [UIColor blackColor];//DARK_VIEW;
        polygonView.alpha = 0.4;
    }
    else if((values < 0.2) && (values > 0.1)) {
        polygonView.backgroundColor = [UIColor blackColor];//DARK_VIEW;
        polygonView.alpha = 0.2;
    }
    else if((values < 0.3) && (values > 0.2)) {
        polygonView.backgroundColor = [UIColor blackColor];//DARK_VIEW;
        polygonView.alpha = 0.1;
    }
    else if((values < 0.4) && (values > 0.3)) {
        polygonView.backgroundColor = [UIColor blackColor];//DARK_VIEW;
        polygonView.alpha = 0.0;
    }
    else if((values < 0.5) && (values > 0.4)) {
        polygonView.backgroundColor = [UIColor whiteColor];//DARK_VIEW;
        polygonView.alpha = 0.1;
    }
    else if((values < 0.6) && (values > 0.5)) {
        polygonView.backgroundColor = [UIColor whiteColor];//DARK_VIEW;
        polygonView.alpha = 0.2;
    }



    NSLog(@"vakdfjkdf %f",values );
    [self.view addSubview:polygonView];
    [self.view bringSubviewToFront:polygonView];
    [polygonView release];


}

推荐答案

是的，你可以通过在视图上添加blackView并根据滑块值更改其alpha来实现这一点..看起来你正在改变亮度。

yeah you can do that by adding a blackView on your view and change its alpha based on the slider value .. it will looks like you are changing the brightness.

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