我在MainActivity里x新打开一个NewActivity,运行没问题,但是NewActivity的布局完全没有,只有一个白版,为什么?
MainActivity.java
package com.example.hello_2;import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.widget.Button;public class MainActivity extends Activity { @Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button button=(Button)this.findViewById(R.id.button1);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent intent=new Intent(MainActivity.this,NewActivity.class);
startActivity(intent);
}
});
} @Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
}NewActivity.java
package com.example.hello_2;import com.example.hello_2.NewActivity;import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.SubMenu;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;public class NewActivity extends Activity{
protected void onCreat(Bundle savedInstanceState1){
super.onCreate(savedInstanceState1);
setContentView(R.layout.activity_first);
Log.d("NewActivity", "onCreat");
}
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
return super.onCreateOptionsMenu(menu);
}}
MainActivity.java
package com.example.hello_2;import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.widget.Button;public class MainActivity extends Activity { @Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button button=(Button)this.findViewById(R.id.button1);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent intent=new Intent(MainActivity.this,NewActivity.class);
startActivity(intent);
}
});
} @Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
}NewActivity.java
package com.example.hello_2;import com.example.hello_2.NewActivity;import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.SubMenu;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;public class NewActivity extends Activity{
protected void onCreat(Bundle savedInstanceState1){
super.onCreate(savedInstanceState1);
setContentView(R.layout.activity_first);
Log.d("NewActivity", "onCreat");
}
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
return super.onCreateOptionsMenu(menu);
}}
R.layout.activity_first
里面写了布局吗?
@Override
protected void onCreate(Bundle savedInstanceState1){
super.onCreate(savedInstanceState1);
setContentView(R.layout.activity_first);
Log.d("NewActivity", "onCreat");
}
使用 @Override 注释添加 e. Consider。