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();
            }
        });
    }
}