iOS设置系统导航栏是颜色感觉变浅

设置系统导航时，颜色感觉变浅，并且项目的布局已经完成了的情况下可以给你的导航栏基类里插入一个大小宽高为frame.size.width, frame.size.height+20的底图 

话不多说上代码：

<pre>

if([[UIDevicecurrentDevice].systemVersionintegerValue] >9) {

for(UIView* viewinself.navigationBar.subviews) {

if([viewisKindOfClass:NSClassFromString(@"_UIBarBackground")]) {

view.hidden=YES;

view.frame= (CGRect){0,0,0,0};

for(UIView*separatorinview.subviews) {

if([separatorisKindOfClass:[UIImageViewclass]]) {

[separatorsetHidden:YES];

}

}

}

}

}

UIView* alphaView = [[UIViewalloc]initWithFrame:CGRectMake(0,0,self.navigationBar.frame.size.width,self.navigationBar.frame.size.height+20)];

alphaView.alpha=1;

alphaView.backgroundColor=NavBar_Bg_Color;

[self.navigationBarsetBackgroundImage:[[UIImagealloc]init]forBarMetrics:UIBarMetricsCompact];

[self.viewinsertSubview:alphaViewbelowSubview:self.navigationBar];

<pre/>

完成