iOS开发中对于摄像头的一些基本使用方法分享

在一些应用中，我们需要用到ios设备的摄像头进行拍照，视频。并且从相册中选取我们需要的图片或者视频。
关于ios摄像头和相册的应用，可以使用uiimagepickercontroller类来完成控制。

uiimagepickercontroller 这个类可以为大家提供照相的功能,以及图片,视频浏览的功能。

检查硬件是否安装有摄像头或者允许操作相册

#pragma mark - 摄像头和相册相关的公共类

// 判断设备是否有摄像头
- (bool) iscameraavailable{
return [uiimagepickercontroller issourcetypeavailable:uiimagepickercontrollersourcetypecamera];
}

// 前面的摄像头是否可用
- (bool) isfrontcameraavailable{
return [uiimagepickercontrolleriscameradeviceavailable:uiimagepickercontrollercameradevicefront];
}

// 后面的摄像头是否可用
- (bool) isrearcameraavailable{
return [uiimagepickercontrolleriscameradeviceavailable:uiimagepickercontrollercameradevicerear];
}

调用摄像头

- (bool) hasmultiplecameras {
nsarray *devices = [avcapturedevice deviceswithmediatype:avmediatypevideo];
if (devices != nil && [devices count] > 1) return yes;
return no;
}

- (avcapturedevice *)camerawithposition : (avcapturedeviceposition) position
{
nsarray *devices = [avcapturedevice deviceswithmediatype:avmediatypevideo];
for (avcapturedevice *device in devices )
if ( device.position == position )
return device;

return nil ;
}

- (void) swapfrontandbackcameras {
//check for available cameras!
if (![self hasmultiplecameras]) return;

//assumes session is running
nsarray *inputs = self.capturesession.inputs; //should only be one value!
for ( avcapturedeviceinput *capturedeviceinput in inputs ) {
avcapturedevice *device = capturedeviceinput.device ;
if ( [device hasmediatype:avmediatypevideo ] ) {
avcapturedeviceposition position = device.position ;
avcapturedevice *newcamera = nil ;
avcapturedeviceinput *newinput = nil ;

if (position == avcapturedevicepositionfront)
newcamera = [self camerawithposition:avcapturedevicepositionback];
else
newcamera = [self camerawithposition:avcapturedevicepositionfront];

[self initializecapturedevice:newcamera];
newinput = [avcapturedeviceinput deviceinputwithdevice:newcamera error:nil];

// beginconfiguration ensures that pending changes are not applied immediately
[self.capturesession beginconfiguration ];

[self.capturesession removeinput:capturedeviceinput]; //remove current
[self.capturesession addinput:newinput]; //add new

// changes take effect once the outermost commitconfiguration is invoked.
[self.capturesession commitconfiguration];
break ;
}
}
}

上面的代码是使用前置摄像头和后置摄像头！