实现Activity数据中间的协同

最新推荐文章于 2021-05-28 09:15:08 发布

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本文详细介绍了如何使用Android的startActivityForResult方法在两个Activity间通过Intent传递数据，并在返回时获取B Activity的数据以更新A Activity的显示。

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Activity A 中启动 Activity B 并通过 Intent传递一些数据到B，那么B的数据怎么在返回给A。

Android 提供了startActivityForResult方法。

例子：

activity_comm_1.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
	android:orientation="vertical" android:layout_width="match_parent"
	android:layout_height="match_parent">
	<TextView android:text="请随便说点什么"
	android:id="@+id/textView1" 
	android:layout_width="match_parent" 
	android:layout_height="wrap_content"
	android:layout_weight="1"></TextView>
	<Button android:text="编辑" 
	android:id="@+id/edit"
		android:layout_width="wrap_content" 
		android:layout_height="wrap_content"
		android:layout_gravity="center_horizontal"></Button>
</LinearLayout>

Activity_comm_1.java：

package com.demo.intent;

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

public class Activity_comm_1 extends Activity {

	public static int start_flag = 1;
	TextView text = null;

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_comm_1);

		Button startButton = (Button) findViewById(R.id.edit);
		startButton.setOnClickListener(new View.OnClickListener() {
			public void onClick(View view) {
				Intent i = new Intent(Activity_comm_1.this,
						Activity_comm_2.class);
				Bundle bd = new Bundle();
				text = (TextView) findViewById(R.id.textView1);
				bd.putString("content", (String) text.getText());
				i.putExtra("attachment", bd);
				startActivityForResult(i, start_flag);

			}
		});

	}

	@Override
	protected void onActivityResult(int requestCode, int resultCode, Intent data) {
		if (requestCode == start_flag) {
			if (resultCode == RESULT_OK) {
				Bundle b = data.getBundleExtra("attachment2");

				text.setText(b.getString("newcontent"));
			} else {
				return;

			}
		}

	}
}

activity_comm_2.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
	android:orientation="vertical" android:layout_width="match_parent"
	android:layout_height="match_parent">
	<EditText android:text="EditText" android:id="@+id/editText1"
		android:layout_width="match_parent" android:layout_height="wrap_content"
		android:layout_weight="1"></EditText>
	<Button android:text="保存" android:id="@+id/save"
		android:layout_width="wrap_content" android:layout_height="wrap_content"
		android:layout_gravity="center_horizontal"></Button>
	<Button android:text="放弃" android:id="@+id/abort"
		android:layout_width="wrap_content" android:layout_height="wrap_content"
		android:layout_gravity="center_horizontal"></Button>
</LinearLayout>

Activity_comm_2.java:

package com.demo.intent;

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

public class Activity_comm_2 extends Activity {
	EditText text = null;

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_comm_2);
		text = (EditText) findViewById(R.id.editText1);
		// 从Intent读取信息
		Intent i = getIntent();
		Bundle b = i.getBundleExtra("attachment");
		String temp = b.getString("content");
		text.setText(temp);
		// setup button listener
		Button saveButton = (Button) findViewById(R.id.save);
		saveButton.setOnClickListener(new View.OnClickListener() {
			public void onClick(View view) {
				Intent i =new Intent(Activity_comm_2.this,Activity_comm_1.class);
				Bundle bd = new Bundle();

				bd.putString("newcontent", String.valueOf(text.getText()));
				i.putExtra("attachment2", bd);
				setResult(RESULT_OK, i);
				finish();
			}
		});
		Button abortButton = (Button) findViewById(R.id.abort);
		abortButton.setOnClickListener(new View.OnClickListener() {
			public void onClick(View view) {
				setResult(RESULT_CANCELED);
				finish();

			}
		});

	}
}