How to manage activity with startActivityForResult

后端 未结 2 725
醉梦人生
醉梦人生 2020-12-21 21:03

I got a situation like this:

Activity A --> B --> C --> D, when D finished, I have to refresh ActivityA to display what I input in ActivityB , ActivityC and Activity

相关标签:
2条回答
  • 2020-12-21 21:33

    I would suggest you to use a single activity and use fragments as forms to enter the data and once all the data is collected you can either save it in shared preference or SQLITE database depending upon the data to be saved then start a new activity to display the data stored
    OR
    create a parceleble object and send this object to new Activity and display it there.

    0 讨论(0)
  • 2020-12-21 21:49

    You can pass on the "target" Activity for the required results from one Activity to the next with Intent.FLAG_ACTIVITY_FORWARD_RESULT. If you start ActivityC for example:

    @OnClick(R.id.btn_two)
    public void toActivityC(){
        Intent intent = new Intent();
        intent.setClass(this, ActivityC.class);
        intent.setFlag( Intent.FLAG_ACTIVITY_FORWARD_RESULT );
        startActivityForResult(intent, 2);
    }
    

    This way the new activity can call setResult(int) and have that result sent back to the reply target of the original activity.

    (quoted from Intent documentation)

    In your case this means also that each Activity (B and C) has to pass the data which has been collected so far along with the Intent used for starting the next Activity. Finally, ActivityD can call setResult() to transmit the data to ActivityA.

    EDIT (1) I'm adding some code to demonstrate how to react if the user presses the BACK key. For simplicity's sake, let's assume that the user would only decide to press BACK while in ActivityD.

    EDIT (2) Note that Intent.putExtra() can take a Bundle, so you can pass a whole Bundle with all your data along instead of transferring all the values one by one to the new Intent. Using one Bundle extra instead of several other extras can result in less lines of code.

    The xml files

    activity_a.xml

    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:orientation="vertical">
        <TextView
            android:text="Results:"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceLarge"/>
    
        <TextView
            android:id="@+id/tv_result1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="---"/>
    
        <TextView
            android:id="@+id/tv_result2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="---"/>
    
        <TextView
            android:id="@+id/tv_result3"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="---"/>
    
        <Button
            android:id="@+id/btn_get_results"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Get results!"/>
    
    </LinearLayout>
    

    activity_b.xml

    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              android:orientation="vertical">
        <TextView
            android:text="The following text will be sent as result:"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"/>
    
        <TextView
            android:id="@+id/tv_result"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textColor="#ff0000"
            android:text="Forwarding Results"/>
    
        <Button
            android:id="@+id/btn_get_results"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Get more results!"/>
    
    </LinearLayout>
    

    activity_c.xml

    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              android:orientation="vertical">
        <TextView
            android:text="The following text will be sent as result:"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"/>
    
        <CheckBox
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textColor="#ff00ff"
            android:text="is"
            android:checked="true"
            android:id="@+id/cb_result"/>
    
        <Button
            android:id="@+id/btn_get_results"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Get more results!"/>
    
    </LinearLayout>
    

    activity_d.xml

    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              android:orientation="vertical">
        <TextView
            android:text="The following text will be sent as result:"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"/>
    
        <TextView
            android:id="@+id/tv_result"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textColor="#0000ff"/>
    
        <Button
            android:id="@+id/btn_send_results"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Send all results!"/>
    
    </LinearLayout>
    

    The activities

    ActivityA

    public class ActivityA extends AppCompatActivity
    {
        static final int REQUEST_CODE = 42;
    
        static final String KEY_RESULT_FROM_B = "result_b";
        static final String KEY_RESULT_FROM_C = "result_c";
        static final String KEY_RESULT_FROM_D = "result_d";
    
        private TextView tvResult1, tvResult2, tvResult3;
        private Button btnGetResults;
    
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_a);
    
        tvResult1 = (TextView) findViewById(R.id.tv_result1);
        tvResult2 = (TextView) findViewById(R.id.tv_result2);
        tvResult3 = (TextView) findViewById(R.id.tv_result3);
    
        btnGetResults = (Button) findViewById(R.id.btn_get_results);
        btnGetResults.setOnClickListener(new View.OnClickListener()
        {
            @Override
            public void onClick(View v)
            {
                startActivityForResult(new Intent(ActivityA.this, ActivityB.class), REQUEST_CODE);
            }
        });
    
    }
    
    
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data)
    {
        if (REQUEST_CODE == requestCode)
        {
            if (resultCode == RESULT_OK)
            {
                tvResult1.setText(data.getStringExtra(KEY_RESULT_FROM_B));
                tvResult2.setText(data.getStringExtra(KEY_RESULT_FROM_C));
                tvResult3.setText(data.getStringExtra(KEY_RESULT_FROM_D));
                btnGetResults.setEnabled(false);
            }
            else
            {
                Toast.makeText(ActivityA.this, "no result", Toast.LENGTH_SHORT).show();
                // do something else
            }
        }
    }
    }
    

    ActivityB

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_b);
    
        TextView tvResult = (TextView) findViewById(R.id.tv_result);
        final String result = tvResult.getText().toString();
    
        Button btnGetResults = (Button) findViewById(R.id.btn_get_results);
        btnGetResults.setOnClickListener(new View.OnClickListener()
        {
            @Override
            public void onClick(View v)
            {
                Intent intent = new Intent(ActivityB.this, ActivityC.class);
                intent.setFlags(Intent.FLAG_ACTIVITY_FORWARD_RESULT);
    
                intent.putExtra(ActivityA.KEY_RESULT_FROM_B, result);
                startActivity(intent);
                finish();
            }
        });
    }
    

    ActivityC

    public class ActivityC extends AppCompatActivity
    {
        static final String IS ="is";
        static final String IS_NOT = "is not";
    
        private CheckBox cbResult;
    
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_c);
    
        cbResult = (CheckBox) findViewById(R.id.cb_result);
        cbResult.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener()
        {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked)
            {
                buttonView.setText(isChecked ? IS : IS_NOT);
            }
        });
    
        String previousResult = getIntent().getStringExtra(ActivityA.KEY_RESULT_FROM_C);
        cbResult.setChecked( ! IS_NOT.equals(previousResult) );
    
        final String result1 = getIntent().getStringExtra(ActivityA.KEY_RESULT_FROM_B);
    
        Button btnGetResults = (Button) findViewById(R.id.btn_get_results);
        btnGetResults.setOnClickListener(new View.OnClickListener()
        {
            @Override
            public void onClick(View v)
            {
                Intent intent = new Intent(ActivityC.this, ActivityD.class);
                intent.setFlags(Intent.FLAG_ACTIVITY_FORWARD_RESULT);
                intent.putExtra(ActivityA.KEY_RESULT_FROM_B, result1);
                String result2= cbResult.getText().toString();
                intent.putExtra(ActivityA.KEY_RESULT_FROM_C, result2);
                startActivity(intent);
                finish();
            }
        });
    }
    }
    

    ActivityD

    public class ActivityD extends AppCompatActivity
    {
        static final String POSSIBLE = "possible :)";
        static final String COMPLICATED = "complicated";
    
        private String result1, result2;
    
        private TextView tvResult;
    
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_d);
    
        tvResult = (TextView) findViewById(R.id.tv_result);
        result1 = getIntent().getStringExtra(ActivityA.KEY_RESULT_FROM_B);
        result2 = getIntent().getStringExtra(ActivityA.KEY_RESULT_FROM_C);
    
        if (ActivityC.IS.equals(result2))
        {
            tvResult.setText(POSSIBLE);
        }
        else
        {
            tvResult.setText(COMPLICATED);
        }
    
    
        Button btnSendResults = (Button) findViewById(R.id.btn_send_results);
        btnSendResults.setOnClickListener(new View.OnClickListener()
        {
            @Override
            public void onClick(View v)
            {
                Intent intent = new Intent();
    
                intent.putExtra(ActivityA.KEY_RESULT_FROM_B, result1);
                intent.putExtra(ActivityA.KEY_RESULT_FROM_C, result2);
                intent.putExtra(ActivityA.KEY_RESULT_FROM_D,  tvResult.getText().toString());
                setResult(RESULT_OK, intent);
                finish();
            }
        });
    }
    
    @Override
    public void onBackPressed()
    {
        // start ActivityC once more
        Intent intent = new Intent(ActivityD.this, ActivityC.class);
        intent.setFlags(Intent.FLAG_ACTIVITY_FORWARD_RESULT);
    
        intent.putExtra(ActivityA.KEY_RESULT_FROM_B, result1);
        // pass this to set the CheckBox like the user left it:
        intent.putExtra(ActivityA.KEY_RESULT_FROM_C, result2);
        startActivity(intent);
        finish();
    }
    }
    
    0 讨论(0)
提交回复
热议问题