#pragma mark textView控件编辑完后键盘隐藏
             - (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text {   
                     if([text isEqualToString:@"\n"]) {
                             [textView resignFirstResponder];
                             return NO;
                      }
                      return YES;
}
#pragma mark iphone 4 摄像头是前后切换 
#import
// Switching between front and back cameras
- (AVCaptureDevice *)cameraWithPosition:(AVCaptureDevicePosition)position
{
    NSArray *devices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
    for ( AVCaptureDevice *device in devices )
        if ( device.position == position )
            return device;
    return nil;
}
- (void)swapFrontAndBackCameras {
    // Assume the session is already running
    NSArray *inputs = self.session.inputs;
    for ( AVCaptureDeviceInput *input in inputs ) {
        AVCaptureDevice *device = input.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];
            newInput = [AVCaptureDeviceInput deviceInputWithDevice:newCamera error:nil];
            // beginConfiguration ensures that pending changes are not applied immediately
            [self.session beginConfiguration];
            [self.session removeInput:input];
            [self.session addInput:newInput];
            // Changes take effect once the outermost commitConfiguration is invoked.
            [self.session commitConfiguration];
            break;
        }
    }
}
# 存储选择的图片到沙盒中   
NSArray *pathArray = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSData *imageData = UIImagePNGRepresentation([info objectForKey:UIImagePickerControllerOriginalImage]);
   
    CFUUIDRef uuidObj = CFUUIDCreate(nil);
    NSString *uuidString = (NSString *)CFUUIDCreateString(nil, uuidObj);
    CFRelease(uuidObj);
    self.pAddress = [[pathArray objectAtIndex:0] stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.png",uuidString]];
    [imageData writeToFile:self.pAddress atomically:YES ];
＃将一个view得外部整成圆角
首先要引用导入QuartzCore.framework这个框架.
并且头部#import
关键代码如下
   
    m_view1.layer.cornerRadius = 10; // 设置边框得圆弧度
    m_view1.layer.masksToBounds = YES;
       
    m_view2.layer.cornerRadius = 10; 
    m_view2.layer.masksToBounds = YES;
    m_view2.layer.borderWidth = 15; // 设置这个圆形边框得宽度
# 引入libxml2.dylib配置
1 将GDataxMLNode.h和GDataXMLNode.m文件加入到项目中(不一定非得有要GDataXML，也可以其他读写XML类库)
2 进入Xcode,打开Project->Edit Project Settings
3 进入Build Tab
4 找到Linking段，在Other Linker Flags设置中填上：-lxml2
5 找到Search Paths段，在Header Search Paths设置值为：/usr/include/libxml2
6 然后就可以使用GDataXML来解析xml了。