activity页面跳转

关于activity页面跳转的作业
现在我们开始学会做出想要的布局界面，然后运用java来运行实现界面的跳转。
以下是第一个界面的布局代码：

<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"

android:orientation="horizontal">

<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginRight="10dp"
android:layout_weight="1"
android:onClick="onClick"
android:text="退出"
android:textSize="25dp"

/>

第一个布局界面的java代码如下：
package com.example.qwer;

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;

public class TestActivity extends AppCompatActivity {
private TextView radio;
private String name;
public static TestActivity testActivity = null;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_text);
radio= (TextView) findViewById(R.id.radio);

testActivity =this;
MainActivity.mainActivity.finish();
Bundle bundle = getIntent().getExtras();
name = bundle.getString("radio");
radio.setText(name+"同学学习android有没有信心?");
}
public void onClick(View view){

Intent intent = new Intent(TestActivity.this,MainActivity.class);
switch (view.getId()){
intent.putExtra("name",name);
intent.putExtra("w","评估内容返回为:有");
startActivity(intent);
break;

intent.putExtra("name",name);
intent.putExtra("w","评估内容返回为:没有");
startActivity(intent);
break;
}
}
}
第一个界面点击进入评估进入第二个布局界面：


再是第二个界面的java代码：
package com.example.qwer;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
private EditText activity_qwer;
private TextView w;
public static MainActivity mainActivity = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

w=(TextView) findViewById(R.id.w);
mainActivity =this;

try {
MainActivity.mainActivity.finish();
Intent intent = getIntent();
String result = intent.getStringExtra("w");
String name=intent.getStringExtra("name");
activity_qwer.setText(name);
w.setText(result);
}catch (Exception e){

}
}

public void onClick(View view){
switch (view.getId()){

String name = activity_qwer.getEdit().toString();
Intent intent = new Intent(MainActivity.this,MainActivity.class);
Bundle bundle = new Bundle();
bundle.putString("radio",name);
intent.putExtras(bundle);
startActivity(intent);
break;
finish();
MainActivity.mainActivity.finish();
break;
}
}
}