java - 如何将值从父 Activity 传递到子 Activity 以及在子 Activity 退出时刷新父 Activity

Question

我有 3 个 Activity 。

1. 主窗口 5 个按钮
2. 在按钮的主窗口中按下此窗口打开(将其称为父窗口)
3. 在父窗口按钮上按下此窗口打开调用它作为结束子窗口。

现在从子窗口我从父窗口获取值如下:

    // Set - from Window1
    Intent MyRotationsAddPicture1 = new Intent(getBaseContext(), MyRotationsAddPicture.class);
    MyRotationsAddPicture1.putExtra("Title", "1");
    MyRotationsAddPicture1.putExtra("Content", "2");               
    startActivity(MyRotationsAddPicture1);

    // Get - from Window2
    Log.d(TAG, getIntent().getExtras().getString("Title"));
    // Workout and exit this Window2 > to go back Window1 and show the latest update on window1
    this.finish(); 
    System.exit(0);

但是现在，在处理完子窗口后，我退出并返回到我之前的父窗口。到达那里后，我如何刷新已修改并需要在父窗口中显示最新图像的 imageView？

Answer 1

在 WIndow1 中:

开始你的 child Activity 作为

Intent MyRotationsAddPicture1 = new Intent(getBaseContext(), MyRotationsAddPicture.class);
    MyRotationsAddPicture1.putExtra("Title", "1");
    MyRotationsAddPicture1.putExtra("Content", "2");               
    startActivityForResult(MyRotationsAddPicture1, 0);

覆盖:

    protected void onActivityResult(int requestCode, int resultCode, Intent data) {

}

在窗口 2 中:

// Get - from Window2
    Log.d(TAG, getIntent().getExtras().getString("Title"));
    // Workout and exit this Window2 > to go back Window1 and show the latest update on window1
setResult(0);
    this.finish(); 

protected void onActivityResult (int requestCode, int resultCode, Intent data)

Added in API level 1 Called when an activity you launched exits, giving you the requestCode you started it with, the resultCode it returned, and any additional data from it. The resultCode will be RESULT_CANCELED if the activity explicitly returned that, didn't return any result, or crashed during its operation.