Activity组件(传递数据)

（一）

1.效果图：点击按钮“调用第二个Activity”，转到第二页面，之后点击“返回数据”，将第二个页面的数据传到第一个页面

       

2.

activity_main.xml

 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout 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="com.example.app4.MainActivity"
     android:orientation="vertical">

     <Button
         android:id="@+id/btn_start"
         android:text=" 调用第二个Activity"
         android:layout_width="match_parent"
         android:layout_height="wrap_content" />
     <TextView
         android:id="@+id/tv_show"
         android:textSize="40dp"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         />
 </LinearLayout>

slayout.xml

 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:orientation="vertical">
     <Button
         android:id="@+id/btn_back"
         android:text="返回数据"
         android:layout_width="match_parent"
         android:layout_height="wrap_content" />

 </LinearLayout>

3.

MianActivty.java

 package com.example.app4;

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

 public class MainActivity extends AppCompatActivity {
     private Button button;
     private TextView textView;
     private Intent intent;

     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
         button = (Button)findViewById(R.id.btn_start);
         textView = (TextView)findViewById(R.id.tv_show);

         button.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
                 intent = new Intent(MainActivity.this,SActivity.class);
                 startActivityForResult(intent,0);
             }
         });
     }

     @Override
     protected void onActivityResult(int requestCode, int resultCode, Intent data) {
         super.onActivityResult(requestCode, resultCode, data);
         if (requestCode==0&&resultCode==0){
             String info = data.getStringExtra("info");
             textView.setText(info);
         }
     }
 }

SActivty.java

package com.example.app4;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;

/**
 * Created by Administrator on 2018/5/23.
 */
public class SActivity extends Activity {
    private Button button;
    private String content ="你好，我是从SActivity传递回来的数据";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.slayout);
        button=(Button)findViewById(R.id.btn_back);

        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent data = new Intent();
                data.putExtra("info",content);
                setResult(0,data);

                finish();
            }
        });
    }
}