问题
I want to move from one activity to another (using virtual device). When I click on button to move, My emulator ones a dialog box showing unfortunately SMS1 has stopped working (SMS1 is my app name).
Can anybody help me in correcting my code?
MainActivity.java:
package com.example.sms1;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
public class MainActivity extends Activity implements OnClickListener
{
Button b1;
TextView tv1;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
b1 = (Button) findViewById(R.id.button1);
tv1 = (TextView) findViewById(R.id.textView1);
b1.setOnClickListener(this);
}
@Override
public boolean onCreateOptionsMenu(Menu menu)
{
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public void onClick(View v)
{
// TODO Auto-generated method stub
Intent i = new Intent(getApplicationContext(),NextActivity.class);
startActivity(i);
setContentView(R.layout.avtivity_next);
}
}
Here is the NextActivity
package com.example.sms1;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.widget.TextView;
public class NextActivity extends Activity {
TextView tv1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.avtivity_next);
tv1 = (TextView) findViewById(R.id.textView1);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
Manifest.XML
<?xml version=\"1.0\" encoding=\"utf-8\"?>
<manifest xmlns:android=\"http://schemas.android.com/apk/res/android\"
package=\"com.example.sms1\"
android:versionCode=\"1\"
android:versionName=\"1.0\" >
<uses-sdk
android:minSdkVersion=\"8\"
android:targetSdkVersion=\"17\" />
<application
android:allowBackup=\"true\"
android:icon=\"@drawable/ic_launcher\"
android:label=\"@string/app_name\"
android:theme=\"@style/AppTheme\" >
<activity
android:name=\"com.example.sms1.MainActivity\"
android:label=\"@string/app_name\" >
<intent-filter>
<action android:name=\"android.intent.action.MAIN\" />
<category android:name=\"android.intent.category.LAUNCHER\" />
</intent-filter>
</activity>
</application>
</manifest>
NextActivityLayout
<RelativeLayout xmlns:android=\"http://schemas.android.com/apk/res/android\"
xmlns:tools=\"http://schemas.android.com/tools\"
android:layout_width=\"match_parent\"
android:layout_height=\"match_parent\"
android:paddingBottom=\"@dimen/activity_vertical_margin\"
android:paddingLeft=\"@dimen/activity_horizontal_margin\"
android:paddingRight=\"@dimen/activity_horizontal_margin\"
android:paddingTop=\"@dimen/activity_vertical_margin\"
tools:context=\".NextActivity\" >
<TextView
android:id=\"@+id/textView1\"
android:layout_width=\"wrap_content\"
android:layout_height=\"wrap_content\"
android:text=\"next activity\" />
</RelativeLayout>
MainActivity Layout
<RelativeLayout xmlns:android=\"http://schemas.android.com/apk/res/android\"
xmlns:tools=\"http://schemas.android.com/tools\"
android:layout_width=\"match_parent\"
android:layout_height=\"match_parent\"
android:paddingBottom=\"@dimen/activity_vertical_margin\"
android:paddingLeft=\"@dimen/activity_horizontal_margin\"
android:paddingRight=\"@dimen/activity_horizontal_margin\"
android:paddingTop=\"@dimen/activity_vertical_margin\"
tools:context=\".MainActivity\" >
<TextView
android:id=\"@+id/textView1\"
android:layout_width=\"wrap_content\"
android:layout_height=\"wrap_content\"
android:text=\"@string/hello_world\" />
<Button
android:id=\"@+id/button1\"
android:layout_width=\"wrap_content\"
android:layout_height=\"wrap_content\"
android:layout_below=\"@+id/textView1\"
android:layout_marginTop=\"80dp\"
android:layout_toRightOf=\"@+id/textView1\"
android:text=\"Button\" />
</RelativeLayout>
回答1:
You haven't defined NextActivity in the AndroidManifest.xml file.
Add these lines in android manifest after</activity> tag. It should work.
<activity
android:name=".NextActivity" >
</activity>
final code will be
<application
android:allowBackup="true"
android:icon="@drawable/app_icon"
android:label="@string/app_name" >
<activity
android:name=".MainActivity"
android:label="Main Activity" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".NextActivity" >
</activity>
</application>
回答2:
First You have to use this code in MainActivity.java class
@Override
public void onClick(View v)
{
// TODO Auto-generated method stub
Intent i = new Intent(getApplicationContext(),NextActivity.class);
startActivity(i);
}
You can pass intent this way.
Second
add proper entry into manifest.xml file.
<activity android:name=".NextActivity" />
Now see what happens.
回答3:
Simply add your NextActivity in the Manifest.XML file
<activity
android:name="com.example.sms1.NextActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
</intent-filter>
</activity>
回答4:
button1 in activity2
code written in activity 2
button1.setOnClickListener(new View.OnClickListener() {
public void onClick(View v)
{
// starting background task to update product
Intent fp=new Intent(getApplicationContext(),activity1.class);
startActivity(fp);
}
});
This might help
回答5:
1) place setContentView(R.layout.avtivity_next); to the next-activity's onCreate() method just like this (main) activity's onCreate()
2) if you have not defined the next-activity in your-apps manifest file then do this also, like:
<application
android:allowBackup="true"
android:icon="@drawable/app_icon"
android:label="@string/app_name" >
<activity
android:name=".MainActivity"
android:label="Main Activity" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".NextActivity"
android:label="Next Activity" >
</activity>
</application>
You must have to perform the 2nd step every time you create a new activity, otherwise your app will crash
回答6:
When you have to go from one page to another page in android changes made in 2 files
Intent intentSignUP = new Intent(this,SignUpActivity.class);
startActivity(intentSignUP);
add activity in androidManifest file also like
<activity android:name=".SignUpActivity"></activity>
回答7:
setContentView(R.layout.avtivity_next);
I think this line of code should be moved to the next activity...
回答8:
public void onClick(View v)
{
startActivity(new Intent(getApplicationContext(), Next.class));
}
it is direct way to move second activity and there is no need for call intent
回答9:
Below code is working fine with Android 4.3:
Intent i = new Intent(this,MainActivity2.class);
startActivity(i);
回答10:
First you have to declare the activity in Manifest. It is important. You can add this inside application like this.
回答11:
It is mainly due to unregistered activity in manifest file as "NextActivity" Firstly register NextActivity in Manifest like
<activity android:name=".NextActivity">
then use the code in the where you want
Intent intent=new Intent(MainActivity.this,NextActivity.class);
startActivity(intent);
where you have to call the NextActivity..
回答12:
Register your java class on Android manifest file
After that write this code on button click
startActivity(new intent(MainActivity.this,NextActivity.class));
回答13:
@Override
public void onClick(View v)
{
// TODO Auto-generated method stub
Intent intent = new Intent(Activity1.this,Activity2.class);
startActivity(intent);
}
回答14:
You can do
Intent i = new Intent(classname.this , targetclass.class);
startActivity(i);
来源：https://stackoverflow.com/questions/17526533/moving-from-one-activity-to-another-activity-in-android