DALSA gige相机有两种方式可以获取到相机相关参数，一个是读取相机里面的xml文件；另外一个是读取相对应的寄存器的值。
对于修改寄存器的值，有两个相应的函数：
1）GevSetFeatureValue
函数原型为：
GEV_STATUS GevSetFeatureValue(GEV_CAMEAR_HANDLE handle, const char *feature_name, int value_size, void *value);
2）GevSetFeatureValueAsString
函数原型为：
GEV_STATUS GevSetFeatureValueAsString(GEV_CAMERA_HANDLE handle, const char *feature_name, char *value_string);
两者之间端区别在于，GevSetFeatureValue 可以配置任意类型（支持的类型）的值，并且需要手动填写类型。而GevSetFeatureValueAsString 是固定为string类型，只需要填写相对应端值即可。
还有一个更重要的区别是，GevSetFeatureValue能够配置的项在文件 cameraregdata.c 中有对应，许多项配置不了，受制于结构体
typedef struct
{
char featureName[FEATURE_NAME_MAX_SIZE]; // String name of feature for this register.
UINT32 address; // Address for accessing feature in camera (NOREF_ADDR if not in camera).
RegAccess accessMode; // RO, WO, RW access allowed.
BOOL32 available; // True if feature is available (in camera or not) - False is not available.
RegType type; // String, Float, Integer, Enum, Bit
UINT32 regSize; // Size of storage for register (or register set / area).
UINT32 regStride; // Increment between register items accessed via selector
UINT32 minSelector; // Minimum value for selector (corresponds to base address).
UINT32 maxSelector; // Maximum value for selector.
GENIREG_VALUE value; // Current value (storage for features not backed by a register).
GENIREG_VALUE minValue; // Minimum allowable value.
GENIREG_VALUE maxValue; // Maximum allowable value.
UINT32 readMask; // AND Mask for read (integers only)
UINT32 writeMask; // AND Mask for write (integers only)
PGENICAM_FEATURE feature; // Pointer to feature in feature table (future).
char selectorName[FEATURE_NAME_MAX_SIZE]; // String name of selector for feature.
char indexName[FEATURE_NAME_MAX_SIZE]; // String name of index (second selector)for feature.
} GEV_REGISTER, *PGEV_REGISTER;
中accessMode 和 available 等属性。
而 GevSetFeatureValueAsString 却能够配置 featureName存在的项，能力远远大于 GevSetFeatureValue 。