Android的"onActivityResult"机制不起作用

问题描述

使用简单的应用程序，我遇到了一个大而令人沮丧的问题.我有两个活动-A和B.活动A在单击按钮时打开活动B.活动B有两个结束":如果用户单击B.返回，如果刚刚结束并返回到A，如果用户单击B.OK按钮，则活动B已完成，但在此之前将结果设置为确定"，因此可以关闭活动A也是.

I have a big and frustrating problem with a simple application.I have two Activities - A and B. Activity A opens activity B on a button click. Activity B has two "ends": If user clicks B.Back if just finish and goes back to A, if user clicks B.OK button, activity B is finished but before that it sets result "OK" so activity A can be closed too.

这是A的伪代码:

btnNext.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                                //some code...
                startAct(data);
            }
        });

private void startAct(Intent inte) {
        startActivityForResult(inte, -999);
    }

@Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        System.out.println(resultCode);

        if(requestCode != -999)
            return;

        if(resultCode == RESULT_OK)
            finish();
    }

活动B这样做:

btnOk.setOnClickListener(new OnClickListener() {
                @Override
                public void onClick(View v) {
                    //some other code...
                    finishOK();
                }
            });

private void finishOK() {
        setResult(RESULT_OK, new Intent());
        finish();
    }

问题是，这将不起作用-当我按"btnOK"时，B应该完成，A应该也捕获"结果并完成，但是根本不会发生.我想念什么?

The problem is that this won't work - when i press the "btnOK" B should finish, A should "catch" the result and finish too, but it simply won't happen. What am i missing?

推荐答案

您必须使用非负数requestCode.如果requestCode为负，则startActivityForResult与startActivity相同.请参阅官方文档 http://developer.android.com/reference/android/app/Activity.html#startActivityForResult(android.content.Intent,%20int)

You have to use a non-negative requestCode. If the requestCode is negative then startActivityForResult is the same as startActivity. See official document http://developer.android.com/reference/android/app/Activity.html#startActivityForResult(android.content.Intent,%20int)

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