Start new Activity by existing Activity on a button click
Hi, guys. In this article we will see how to start a new Activity on a button click in the current activity.
There are two types of ways to open a new activity.
Using the "startactivity(Intent intent)" method and "startActivityforResult(Intent intent, requestCode requestCode)" method.
When we open a folder or file using another for importing or save some data then we use startActivityforResult(),
Because by calling this second Activity the open is only for some time and provides some output.
Whereas startActivity() opens a separate new activity.
Step 1
Create a new project: "DemoActivity File" --> "New" --> "Android Application Project".
new prjt.jpg
Step 2
Open "DemoActivity /res/values/string.xml" and update it as in the following code:
  1. <?xml version="1.0" encoding="utf-8"?>
  2. <resources>
  3. <string name="app_name">MyDemo</string>
  4. <string name="hello_world">Hello world!, this is my android application </string>
  5. <string name="lblBtn">Open Activity Demo</string>
  6. <string name="btn"></string>
  7. <string name="lblTxt">This is another activity sarting by main activity</string>
  8. <string name="menu_settings">Settings</string>
  9. </resources>
Step 3
Open "DemoActivity/AndroidManifest.xml" and update it as in the following code:
  1. <?xml version="1.0" encoding="utf-8"?>
  2. <manifest xmlns:android="http://schemas.android.com/apk/res/android"
  3. package="com.example.mydemo"
  4. android:versionCode="1"
  5. android:versionName="1.0" >
  6. <uses-sdk
  7. android:minSdkVersion="8"
  8. android:targetSdkVersion="17" />
  9. <application
  10. android:allowBackup="true"
  11. android:icon="@drawable/ic_launcher"
  12. android:label="@string/app_name"
  13. android:theme="@style/AppTheme" >
  14. <activity
  15. android:name="com.example.mydemo.MainActivity"
  16. android:label="@string/app_name" >
  17. <intent-filter>
  18. <action android:name="android.intent.action.MAIN" />
  19. <category android:name="android.intent.category.LAUNCHER" />
  20. </intent-filter>
  21. </activity>
  22. <activity
  23. android:name=".AnotherActivity"
  24. android:label="@string/app_name">
  25. <intent-filter >
  26. <action android:name="in.wptrafficanalyzer.AnotherActivity"/>
  27. <category android:name="android.intent.category.DEFAULT"/>
  28. </intent-filter>
  29. </activity>
  30. </application>
  31. </manifest>
Step 4
Create a new Java file in the "com.example.mydemo" package named "AnotherActivity.java" with the following code:
  1. package com.example.mydemo;
  2. import android.app.Activity;
  3. import android.os.Bundle;
  4. public class AnotherActivity extends Activity{
  5. @Override
  6. protected void onCreate(Bundle savedInstanceState) {
  7. // TODO Auto-generated method stub
  8. super.onCreate(savedInstanceState);
  9. setContentView(R.layout.another);
  10. }
  11. }
Step 5
Create a new XML file in the "Demo/res/layout/" directory as "activity_another.xml" with the following code:
  1. <?xml version="1.0" encoding="utf-8"?>
  2. <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  3. android:layout_width="match_parent"
  4. android:layout_height="match_parent"
  5. android:orientation="vertical" >
  6. <TextView
  7. android:id="@+id/txt"
  8. android:layout_width="match_parent"
  9. android:layout_height="wrap_content"
  10. android:text="@string/lblTxt"
  11. />
  12. </LinearLayout>
Step 6
Open "Demo/src/com.example.mydemo/MainActivity.java" and update it as in the following code:
  1. package com.example.mydemo;
  2. import android.os.Bundle;
  3. import android.app.Activity;
  4. import android.content.Intent;
  5. import android.view.Menu;
  6. import android.view.View;
  7. import android.view.View.OnClickListener;
  8. import android.widget.Button;
  9. public class MainActivity extends Activity {
  10. @Override
  11. protected void onCreate(Bundle savedInstanceState) {
  12. super.onCreate(savedInstanceState);
  13. setContentView(R.layout.activity_main);
  14. OnClickListener listnr=new OnClickListener() {
  15. @Override
  16. public void onClick(View v) {
  17. Intent i= new Intent("AnotherActivity");
  18. startActivity(i);
  19. }
  20. };
  21. Button btn =(Button) findViewById(R.id.btn);
  22. btn.setOnClickListener(listnr);
  23. }
  24. }
Step 7
Open "Demo/res/layout/activity_main.xml" and update it with the following code:
  1. <?xml version="1.0" encoding="utf-8"?>
  2. <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  3. xmlns:tools="http://schemas.android.com/tools"
  4. android:layout_width="match_parent"
  5. android:layout_height="match_parent"
  6. tools:context=".MainActivity" >
  7. <TextView
  8. android:layout_width="125dp"
  9. android:layout_height="wrap_content"
  10. android:text="@string/hello_world" />
  11. <Button
  12. android:id="@+id/btn"
  13. android:layout_width="134dp"
  14. android:layout_height="wrap_content"
  15. android:text="@string/lblBtn" />
  16. </LinearLayout>
Run the Application and see the output.
Current Activity:
out1.jpg
New Activity:
2nd otpt.jpg