编译器类型警告和错误

Question

if(xmlStrEquals(cur->name, (const xmlChar *) "check")) // Find out which type it is 
    gtk_toggle_button_set_active(GTK_TOGGLE_BUTTON (gtk_builder_get_object (builder, xmlGetProp(cur,"name"))),(gboolean) xmlGetProp(cur,"value")); 

else if(xmlStrEquals(cur->name, (const xmlChar *) "spin")) 
    gtk_adjustment_set_value(GTK_ADJUSTMENT (gtk_builder_get_object (builder, xmlGetProp(cur,"name"))),(gdouble) xmlGetProp(cur,"value")); 

else if(xmlStrEquals(cur->name, (const xmlChar *) "combo")) 
    gtk_combo_box_set_active(GTK_COMBO_BOX (gtk_builder_get_object (builder, xmlGetProp(cur,"name"))),(gint) xmlGetProp(cur,"value")); 

以下3个错误对应于上述3个if语句。

main.c:125: warning: cast from pointer to integer of different size 
main.c:130: error: pointer value used where a floating point value was expected 
main.c:139: warning: cast from pointer to integer of different size 

如果你允许我提取违规部分：

(gboolean) xmlGetProp(cur,"value") 
(gdouble) xmlGetProp(cur,"value") 
(gint) xmlGetProp(cur,"value") 

为什么这些类型转换导致这些错误？我该如何解决它们？

尝试使用(gboolean *)等从GTK的线沿线收到警告：

warning: passing argument 2 of ‘gtk_toggle_button_set_active’ makes integer from pointer without a cast 
/usr/include/gtk-2.0/gtk/gtktogglebutton.h:82: note: expected ‘gboolean’ but argument is of type ‘gboolean *’ 
error: incompatible type for argument 2 of ‘gtk_adjustment_set_value’ 
/usr/include/gtk-2.0/gtk/gtkadjustment.h:93: note: expected ‘gdouble’ but argument is of type ‘gdouble *’ 
warning: passing argument 2 of ‘gtk_combo_box_set_active’ makes integer from pointer without a cast 
/usr/include/gtk-2.0/gtk/gtkcombobox.h:99: note: expected ‘gint’ but argument is of type ‘gint *’ 

Answer 1

我固定它，像这样：

(gboolean) *xmlGetProp(cur,"value") 
(gdouble) *xmlGetProp(cur,"value") 
(gint) *xmlGetProp(cur,"value") 

仍然不知道为什么工作，但我能猜到。

Answer 2

的​​返回一个字符串（如xmlChar *）：

搜索并获得相关的属性值到一个节点这是实体替代。该函数在DTF属性声明中查找#FIXED或默认声明值，除非DTD使用已被关闭。
[...]
返回：属性值或NULL，如果没有找到。这取决于调用者使用xmlFree（）释放内存。

调用者负责将该字符串解析为任何形式（浮点，整数，布尔，...）。另请注意，主叫方也负责释放返回的xmlChar *字符串。

解决您的问题，您需要将字符串转换为你通常的方式所需要的。并且不要忘记xmlFree返回的字符串。