切換Activity畫面

舉例來說如果要把MainActivity.java切換到另一個Activity叫SenconActivity

1.MainActivity.java(畫面1)
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.EditText;

public class MainActivity extends Activity {
EditText etCH,etEN,etMA;
double ch,en,ma;
Button btn1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
findviews();
}
void findviews(){
etCH=(EditText)findViewById(R.id.editText1);
etEN=(EditText)findViewById(R.id.editText2);
etMA=(EditText)findViewById(R.id.editText3);
btn1=(Button)findViewById(R.id.button1);
btn1.setOnClickListener(new OnClickListener() {

public void onClick(View arg0) {
ch=Double.parseDouble(etCH.getText().toString());
en=Double.parseDouble(etEN.getText().toString());
ma=Double.parseDouble(etMA.getText().toString());
//切換至畫面2
Intent intent=new Intent();
intent.setClass(MainActivity.this, SenconActivity.class);
//用Bundle來包要帶的資料
Bundle bundle=new Bundle();
bundle.putDouble("chinese", ch);
bundle.putDouble("english", en);
bundle.putDouble("math", ma);

intent.putExtras(bundle);
startActivity(intent);//開始切換畫面


}
});
}

@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;
}

}

2.SenconActivity .java(畫面2)

在AndroidManifest.xml=>Application=>Application Nodes 裡Add Activity =>Name*欄位 打SenconActivity

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;

import android.widget.TextView;

public class SenconActivity extends Activity {

TextView tvCH,tvEN,tvMA,tvTotal,tvAvg;

double ch,en,ma,total,avg;

Button btn;

@Override

protected void onCreate(Bundle savedInstanceState) {

// TODO Auto-generated method stub

super.onCreate(savedInstanceState);

setContentView(R.layout.secondscreen);

findviews();

}

void findviews(){

tvCH=(TextView)findViewById(R.id.textView1);

tvEN=(TextView)findViewById(R.id.textView2);

tvMA=(TextView)findViewById(R.id.textView3);

tvTotal=(TextView)findViewById(R.id.textView4);

tvAvg=(TextView)findViewById(R.id.textView5);

    Intent intent=getIntent();

   Bundle bundle=intent.getExtras();

   ch=bundle.getDouble("chinese");

   en=bundle.getDouble("english");

   ma=bundle.getDouble("math");

   

tvCH.setText(String.valueOf(ch));

tvEN.setText(String.valueOf(en));

tvMA.setText(String.valueOf(ma));

total=(ch+en+ma);

avg=total/3;

tvTotal.setText(String.valueOf(total));

tvAvg.setText(String.valueOf(avg));

  

btn=(Button)findViewById(R.id.button2);

btn.setOnClickListener(new OnClickListener() {

public void onClick(View v) {

Intent intent =new Intent();

intent.setClass(SenconActivity.this, MainActivity.class);//切換到畫面2

startActivity(intent);

}

});

}

}