Question

要问这个问题可能会非常愚蠢，但我无法找到使其有效的方法，甚至无法在互联网上找到解决方案。

我需要连接2个字符串（变量STR_Prefix和字符串“TA +”）来创建一个新字符串（“ATA +”或“BTA +”），然后我必须检查if语句中的值，但它失败了， if语句没有检测到“ATA +”。

但如果我将“STR_Action”的值直接设置为“ATA +”，则效果非常好。

public void Test(boolean ok)
{
    String STR_Action = "";
    if (ok) { STR_Prefix = "A"; }
    else    { STR_Prefix = "B"; }

    /* I have tried some ways to concatenate */
    STR_Action = STR_Prefix + "TA+";    // Not working with the if-statement
    // STR_Action = new StringBuilder(STR_Prefix).append("TA+").toString();    // Not working with the if-statement

    /* But if-statement only works when I set STR_Action directly with = "ATA+" or "BTA+"; */
    // STR_Action = "ATA+";    // This assign is detected by the if-statement

    if (STR_Action == "ATA+")
    {
        Toast.makeText(getApplicationContext(), "ATA+", 0).show();
    }
    else if (STR_Action == "BTA+")
    {
        Toast.makeText(getApplicationContext(), "ATA-", 0).show();
    }
    else
    {
        Toast.makeText(getApplicationContext(), "Code not found", 0).show();
    }
}

请帮助：'（

提前致谢

Answer 1

尝试使用.equals()方法进行String比较

 if (STR_Action.equals("ATA+"))

Android - if条件不会检测到连锁字符串

1 个答案: