Activity间中使用Intent传值-白红宇

主页面用来输入一个值传入第二个页面显示，关闭第二个页面返回一个值

主页布局：

MainActivity，主要通过startActivityForResult来传递请求码，返回数据的时候，第二个页面调用Activity.setResult()方法设置返回Intent以及返回码，需要重写源Activity的onActivityResult()方法以便于接受返回的Intent，在onActivityResult()中会判断请求码和响应码

package com.example.android01;import android.os.Bundle;import android.R.string;import android.app.Activity;import android.content.Intent;import android.util.Log;import android.view.Menu;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.EditText;import android.widget.Toast;public class MainActivity extends Activity {    private final static String TAG="MainActivity";    private final static int REQUEST_CODE = 1;    private final static String CONTENT = "content";    private EditText txtEditText = null;    private Button btnButton = null;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        txtEditText = (EditText) this.findViewById(R.id.txt);        if (savedInstanceState != null && savedInstanceState.containsKey(CONTENT)) {            txtEditText.setText(savedInstanceState.getString(CONTENT) + "[2]");        }        btnButton = (Button) this.findViewById(R.id.btn);        btnButton.setOnClickListener(new OnClickListener() {            @Override            public void onClick(View v) {                Intent intent = new Intent(MainActivity.this, SecondActivity.class);                String str=txtEditText.getText().toString();                intent.putExtra("fromMain", str);                // startActivity(intent);                // 启动需要监听返回值的Activity，并设置请求码：requestCode                startActivityForResult(intent, REQUEST_CODE);            }        });    }    /*     * (non-Javadoc)     *      * @see android.app.Activity#onActivityResult(int, int,     * android.content.Intent)     */    @Override    protected void onActivityResult(int requestCode, int resultCode, Intent data) {        // 当otherActivity中返回数据的时候，会响应此方法        // requestCode和resultCode必须与请求startActivityForResult()和返回setResult()的时候传入的值一致。        if (requestCode == REQUEST_CODE && resultCode == SecondActivity.RESULT_CODE) {            Bundle bundle=data.getExtras();            String strResult = bundle.getString("result");            Log.i(TAG,"onActivityResult: "+ strResult);            Toast.makeText(MainActivity.this, strResult, Toast.LENGTH_LONG).show();        }    }    /*     * (non-Javadoc) 保存Activity页面状态在onStop之前执行     */    @Override    protected void onSaveInstanceState(Bundle outState) {        // TODO Auto-generated method stub        super.onSaveInstanceState(outState);        String contentString = txtEditText.getText().toString();        outState.putString(CONTENT, contentString);    }    /*     * (non-Javadoc)     *      * @see android.app.Activity#onCreateOptionsMenu(android.view.Menu)     */    @Override    public boolean onCreateOptionsMenu(Menu menu) {        // Inflate the menu; this adds items to the action bar if it is present.        getMenuInflater().inflate(R.menu.activity_main, menu);        return true;    }}

每二个Activity

/** *  */package com.example.android01;import android.app.Activity;import android.content.Intent;import android.os.Bundle;import android.util.Log;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.EditText;import android.widget.TextView;/** * @author Administrator 2014-3-12 下午10:21:17 */public class SecondActivity extends Activity {    private final static String TAG="MainActivity";    public final static int RESULT_CODE=1;    private Button btnBack = null;    private EditText txtContent = null;    private TextView viewContent = null;    /*     * (non-Javadoc)     *      * @see android.app.Activity#onCreate(android.os.Bundle)     */    @Override    protected void onCreate(Bundle savedInstanceState) {        // TODO Auto-generated method stub        super.onCreate(savedInstanceState);        setContentView(R.layout.secondactivity);        txtContent = (EditText) this.findViewById(R.id.txtContent);        viewContent = (TextView) this.findViewById(R.id.viewContent);        btnBack = (Button) this.findViewById(R.id.btnBack);        Intent intent = getIntent();        Bundle bundle = intent.getExtras();        String strContentString = bundle.getString("fromMain");        Log.i(TAG,"SecondActivity: "+ strContentString);        viewContent.setText(strContentString);        btnBack.setOnClickListener(new OnClickListener() {            @Override            public void onClick(View arg0) {                Intent intent = new Intent();                intent.putExtra("result", txtContent.getText().toString());                setResult(RESULT_CODE, intent);// 设置resultCode，onActivityResult()中能获取到                finish();            }        });    }}

注意请求码与返回码的对应判断，因为可能有多个请求码与返回码。

本文转自欢醉博客园博客，原文链接http://www.cnblogs.com/zhangs1986/p/3603590.html如需转载请自行联系原作者

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