如何在Smali语言中实现两个字符串的拼接操作？

如果你需要在Smali代码里完成两个字符串的拼接，最常用的方式就是借助StringBuilder来实现，下面是一个完整的示例：

new-instance v9, Ljava/lang/StringBuilder;
invoke-direct {v9}, Ljava/lang/StringBuilder;-><init>()V
invoke-virtual {v9, v5}, Ljava/lang/StringBuilder;->append(Ljava/lang/String;)Ljava/lang/StringBuilder;
invoke-virtual {v9, v2}, Ljava/lang/StringBuilder;->append(Ljava/lang/String;)Ljava/lang/StringBuilder;
invoke-virtual {v9}, Ljava/lang/StringBuilder;->toString()Ljava/lang/String;
move-result-object v9

代码逐行解释： #

• new-instance v9, Ljava/lang/StringBuilder;：创建一个StringBuilder实例，将其引用存储到寄存器v9中
• invoke-direct {v9}, Ljava/lang/StringBuilder;-><init>()V：调用StringBuilder的无参构造方法，完成实例初始化
• invoke-virtual {v9, v5}, Ljava/lang/StringBuilder;->append(Ljava/lang/String;)Ljava/lang/StringBuilder;：调用append方法，把寄存器v5指向的字符串添加到StringBuilder里
• invoke-virtual {v9, v2}, Ljava/lang/StringBuilder;->append(Ljava/lang/String;)Ljava/lang/StringBuilder;：再次调用append方法，拼接寄存器v2指向的字符串
• invoke-virtual {v9}, Ljava/lang/StringBuilder;->toString()Ljava/lang/String;：调用toString方法，将StringBuilder中的内容转换为最终的字符串对象
• move-result-object v9：把toString方法返回的拼接完成的字符串，重新存储到寄存器v9中

内容的提问来源于stack exchange，提问作者Mhd Zaher Al Katsha