Main5Activity.java 代码如下：

//每点击一次按钮，Button都会＋1；
public class Main5Activity extends AppCompatActivity {
    private Button button;
    private TextView textView;
    private Button button1;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main5);

        button=findViewById(R.id.button);
        textView=findViewById(R.id.textView);
        button1=findViewById(R.id.button1);

        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(Main5Activity.this,"sll",Toast.LENGTH_LONG).show();
                textView.setText(String.valueOf(Integer.parseInt((String)textView.getText())+1));
            }
        });
        button1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent =new Intent(Main5Activity.this,Main3Activity.class);
                intent.putExtra("data","hello world");
                startActivity(intent);
            }
        });
    }
}

activity_main5.xml 代码如下：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="com.lnjr.ll2.Main5Activity">

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="#339933"
        android:textSize="30sp"
        android:text="0"

        />

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"

        />
    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />


</LinearLayout>

Main3activity.java 代码如下：

public class Main3Activity extends AppCompatActivity {

    private EditText editText;
    private ImageView imageView;
    private TextView textView;
    private ProgressBar progressBar;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main3);
        Button button = (Button) findViewById(R.id.button);
        editText = (EditText) findViewById(R.id.edit_text);
        imageView =(ImageView) findViewById(R.id.image_View);
        progressBar=(ProgressBar)findViewById(R.id.progress_bar);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                switch (v.getId()){
                    case R.id.button:
                        imageView.setImageResource(R.drawable.banbana);
                        AlertDialog.Builder dialog=new AlertDialog.Builder(Main3Activity.this);
                        dialog.setTitle(" not allow");
                        dialog.setMessage("Loading...");
                        dialog.setCancelable(true);
                        dialog.setPositiveButton("OK", new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                            }
                        });
                       dialog.setPositiveButton("Cancel", new DialogInterface.OnClickListener() {
                           @Override
                           public void onClick(DialogInterface dialog, int which) {
                           }
                       });
                       dialog.show();
                        int progress=progressBar.getProgress();
                        progress=progress+10;
                        progressBar.setProgress(progress);
                        if (progressBar.getVisibility()==View.GONE){
                            progressBar.setVisibility(View.VISIBLE);
                        }else {
                            progressBar.setVisibility(View.GONE);
                        }
                        break;
                        default:
                            break;
                }
            }
        });

        String s=getIntent().getStringExtra("data");
    }
    }

activity_main3.xml 代码如下：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="com.lnjr.ll2.Main3Activity">
    <TextView
        android:id="@+id/textView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="琳琳"
        android:gravity="center"
        android:textSize="24sp"
        android:textColor="#00ff00"
        />

    <Button
        android:id="@+id/button"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Button"
        android:textAllCaps="false"
        />
    <EditText
        android:id="@+id/edit_text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Type something here"
        android:maxLines="2"/>

    <ImageView
        android:id="@+id/image_View"
        android:layout_width="200dp"
        android:layout_height="200dp"
        android:src="@drawable/aaa"/>
   <ProgressBar
       android:id="@+id/progress_bar"
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       style="@style/Base.Widget.AppCompat.ProgressBar.Horizontal"
       />

</LinearLayout>