How to use putExtra() and getExtra() for string da

2018-12-31 02:43发布

Can someone please tell me how exactly to use getExtra() and putExtra() for intents? Actually I have a string variable, say str, which stores some string data. Now, I want to send this data from one activity to another activity.

  Intent i = new Intent(FirstScreen.this, SecondScreen.class);   
  String keyIdentifer  = null;
  i.putExtra(strName, keyIdentifer );

and then in the SecondScreen.java

 public void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.table);
        TextView userName = (TextView)findViewById(R.id.userName);
        Bundle bundle = getIntent().getExtras();

        if(bundle.getString("strName")!= null)
        {
            //TODO here get the string stored in the string variable and do 
            // setText() on userName 
        }

    }

I know it is very basic question but unfortunately I am stuck here. Please help.

Thanks,

Edit: Here the string which I am trying to pass from one screen to the other is dynamic. That is I have an editText where I am getting string whatever user types. Then with the help of myEditText.getText().toString() . I am getting the entered value as a string then I have to pass this data.

14条回答
查无此人
2楼-- · 2018-12-31 03:16

Push Data

import android.content.Intent;

    ...

    Intent intent = 
        new Intent( 
            this, 
            MyActivity.class );
    intent.putExtra( "paramName", "paramValue" );
    startActivity( intent );

The above code might be inside the main activity. "MyActivity.class" is the second Activity we want to launch; it must be explicitly included in your AndroidManifest.xml file.

<activity android:name=".MyActivity" />

Pull Data

import android.os.Bundle;

    ...

    Bundle extras = getIntent().getExtras();
    if (extras != null)
    {
        String myParam = extras.getString("paramName");
    }
    else
    {
        //..oops!
    }

In this example, the above code would be inside your MyActivity.java file.

Gotchas

This method can only pass strings. So let's say you need to pass an ArrayList to your ListActivity; a possible workaround is to pass a comma-separated-string and then split it on the other side.

Alternative Solutions

Use SharedPreferences

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只靠听说
3楼-- · 2018-12-31 03:16

Put String in Intent Object

  Intent intent = new Intent(FirstActivity.this,NextAcitivity.class);
  intent.putExtra("key",your_String);
  StartActivity(intent);

NextAcitvity in onCreate method get String

String my_string=getIntent().getStringExtra("key");

that is easy and short method

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泪湿衣
4楼-- · 2018-12-31 03:17

put function

etname=(EditText)findViewById(R.id.Name);
        tvname=(TextView)findViewById(R.id.tvName);

        b1= (ImageButton) findViewById(R.id.Submit);

        b1.setOnClickListener(new OnClickListener() {
            public void onClick(View arg0) {
                String s=etname.getText().toString();

                Intent ii=new Intent(getApplicationContext(), MainActivity2.class);
                ii.putExtra("name", s);
                Toast.makeText(getApplicationContext(),"Page 222", Toast.LENGTH_LONG).show();
                startActivity(ii);
            }
        });



getfunction 

public class MainActivity2 extends Activity {
    TextView tvname;
    EditText etname;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main_activity2);
        tvname = (TextView)findViewById(R.id.tvName);
        etname=(EditText)findViewById(R.id.Name);
        Intent iin= getIntent();
        Bundle b = iin.getExtras();

        if(b!=null)
        {

          String j2 =(String) b.get("name");

etname.setText(j2);
            Toast.makeText(getApplicationContext(),"ok",Toast.LENGTH_LONG).show();
        }
    }
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路过你的时光
5楼-- · 2018-12-31 03:18

Best Method...

SendingActivity

Intent intent = new Intent(SendingActivity.this, RecievingActivity.class);
intent.putExtra("keyName", value);  // pass your values and retrieve them in the other Activity using keyName
startActivity(intent);

RecievingActivity

 Bundle extras = intent.getExtras();
    if(extras != null)
    String data = extras.getString("keyName"); // retrieve the data using keyName 

/// shortest way to recieve data..

String data = getIntent().getExtras().getString("keyName","defaultKey");

//This requires api 12. //the second parameter is optional . If keyName is null then use the defaultkey as data.

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人气声优
6楼-- · 2018-12-31 03:20

A small addendum: you do not have to create your own name for the key, android provides these, f.ex. Intent.EXTRA_TEXT. Modifying the accepted answer:

Intent i = new Intent(FirstScreen.this, SecondScreen.class);   
String strName = null;
i.putExtra(Intent.EXTRA_TEXT, strName);

Then, to retrieve the value try something like:

String newString;
Bundle extras = getIntent().getExtras();
if(extras == null) {
    newString= null;
} else {
    newString= extras.getString(Intent.EXTRA_TEXT);
}
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有味是清欢
7楼-- · 2018-12-31 03:21

Simple, In first Activity-

    EditText name= (EditText) findViewById(R.id.editTextName);
    Button button= (Button) findViewById(R.id.buttonGo);
    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent i = new Intent(MainActivity.this,Main2Activity.class);
            i.putExtra("name",name.getText().toString());
           startActivity(i);
          }
    });

In second Activity-

    @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main2);
    TextView t = (TextView) findViewById(R.id.textView);
    Bundle bundle=getIntent().getExtras();
    String s=bundle.getString("name");
    t.setText(s);
}

You can add if/else conditions if you want.

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