MAX/MSP SDK学习05：A_GIMME方法

今天终于将A_GIMME方法部分的描述看懂了，上周因为太赶时间加上这文档很抽象一直没看懂。也就那么一回事，记录一下。

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A_GIMME方法用于接收多个参数。

①内置消息选择器传递多个参数时一定要使用A_GIMME；

②自定义消息选择器传递多个参数时建议也使用A_GIMME；

#include "ext.h"			// standard Max include, always required
#include "ext_obex.h"		// required for new style Max objecttypedef struct _gimme {t_object	ob;			// the object itself (must be first)/* 自定义属性 */
} t_gimme;void* gimme_new(t_symbol* s, long argc, t_atom* argv);
void gimme_free(t_gimme* x);
void gimme_assist(t_gimme* x, void* b, long m, long a, char* s);
// 自定义函数
void gimme_printArgs(t_gimme* x, t_symbol* s, long argc, t_atom* argv);void* gimme_class;void ext_main(void* r) {t_class* c;// "gimme" 建议和项目名一样，否则在max/msp中创建自定义组件会出问题c = class_new("gimme", (method)gimme_new, (method)gimme_free, (long)sizeof(t_gimme),0L /* leave NULL!! */, A_GIMME, 0);/* you CAN'T call this from the patcher */class_addmethod(c, (method)gimme_assist, "assist", A_CANT, 0);// 注意：这里的"gimme"为自定义的消息选择器，会被加入消息选择器表中；而"anything"为消息选择器表内置// 自定义消息选择器class_addmethod(c, (method)gimme_printArgs, "gimme", A_GIMME, 0); class_register(CLASS_BOX, c); /* CLASS_NOBOX */gimme_class = c;post("I am the gimme object");
}void gimme_assist(t_gimme* x, void* b, long m, long a, char* s) {if (m == ASSIST_INLET) { // inletsprintf(s, "I am inlet %ld", a);} else {	// outletsprintf(s, "I am outlet %ld", a);}
}void gimme_free(t_gimme* x) {;
}/* argc指在创建组件时，直接跟在组件后面的参数个数；argv存储参数具体值*/
void* gimme_new(t_symbol* s, long argc, t_atom* argv) {t_gimme* x = NULL;long i;x = (t_gimme*)object_alloc(gimme_class);return (x);
}// 接收多个参数，并打印所有参数
void gimme_printArgs(t_gimme* x, t_symbol* s, long argc, t_atom* argv) {long i;t_atom* ap = argv;for (int i = 0; i < argc; i++) {switch (atom_gettype(ap)) {case A_LONG:post("arg %ld: %ld", i, atom_getlong(ap));break;case A_FLOAT:post("arg %ld: %lf", i, atom_getfloat(ap));break;case A_SYM:post("arg %ld: %s", i, atom_getsym(ap)->s_name);break;default:post("%ld, unknown atom type: %ld", i, atom_gettype(ap));break;}ap++;}
}

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运行结果：