本人新近才开始接触安卓,看了书以后尝试练习了一下activity切换,现在第一个页面能正常显示,可要切换到第二个页面的时候就出现崩溃错误,提示:,请问各位大大这是怎么回事?
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package com.example.finalproject;import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.widget.Button;
import android.content.Intent;
import android.view.View;
import android.view.View.OnClickListener;public class MainActivity extends Activity { private Button btn1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btn1=(Button) findViewById(R.id.Music);
btn1.setOnClickListener(new OnClickListener()
{ public void onClick(View v)
{
Intent intent = new Intent();
intent.setClass(MainActivity.this, Music.class);
startActivity(intent);
MainActivity.this.finish();
} });
}}
package com.example.finalproject;import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;public class Music extends Activity {
private Button btn2;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.music_wel);
btn2=(Button)findViewById(R.id.MusicReturn);
btn2.setOnClickListener(new OnClickListener()
{
public void onClick(View v)
{
Intent itent=new Intent();
itent.setClass(Music.this, MainActivity.class);
startActivity(itent);
Music.this.finish();
}
});
}
}<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" > <Button
android:id="@+id/MusicReturn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBaseline="@+id/Music"
android:layout_alignBottom="@+id/Music"
android:layout_centerHorizontal="true"
android:text="看漫画" /> <Button
android:id="@+id/button3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="@+id/MusicReturn"
android:layout_marginLeft="22dp"
android:layout_toRightOf="@+id/MusicReturn"
android:text="读小说" /> <TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="44dp"
android:text="欢迎使用三合一智能多媒体中心" /> <Button
android:id="@+id/Music"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_marginBottom="44dp"
android:layout_marginRight="21dp"
android:layout_toLeftOf="@+id/MusicReturn"
android:text="听音乐" /></RelativeLayout>
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" > <Button
android:id="@+id/MusicReturn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_marginBottom="40dp"
android:layout_marginLeft="34dp"
android:text="Button" /></RelativeLayout>
———————————————————————————————————————————
package com.example.finalproject;import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.widget.Button;
import android.content.Intent;
import android.view.View;
import android.view.View.OnClickListener;public class MainActivity extends Activity { private Button btn1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btn1=(Button) findViewById(R.id.Music);
btn1.setOnClickListener(new OnClickListener()
{ public void onClick(View v)
{
Intent intent = new Intent();
intent.setClass(MainActivity.this, Music.class);
startActivity(intent);
MainActivity.this.finish();
} });
}}
package com.example.finalproject;import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;public class Music extends Activity {
private Button btn2;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.music_wel);
btn2=(Button)findViewById(R.id.MusicReturn);
btn2.setOnClickListener(new OnClickListener()
{
public void onClick(View v)
{
Intent itent=new Intent();
itent.setClass(Music.this, MainActivity.class);
startActivity(itent);
Music.this.finish();
}
});
}
}<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" > <Button
android:id="@+id/MusicReturn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBaseline="@+id/Music"
android:layout_alignBottom="@+id/Music"
android:layout_centerHorizontal="true"
android:text="看漫画" /> <Button
android:id="@+id/button3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="@+id/MusicReturn"
android:layout_marginLeft="22dp"
android:layout_toRightOf="@+id/MusicReturn"
android:text="读小说" /> <TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="44dp"
android:text="欢迎使用三合一智能多媒体中心" /> <Button
android:id="@+id/Music"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_marginBottom="44dp"
android:layout_marginRight="21dp"
android:layout_toLeftOf="@+id/MusicReturn"
android:text="听音乐" /></RelativeLayout>
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" > <Button
android:id="@+id/MusicReturn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_marginBottom="40dp"
android:layout_marginLeft="34dp"
android:text="Button" /></RelativeLayout>
解决方案 »
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