Android 多Activity之間跳轉傳值

Android 多Activity之間跳轉傳值

MainActivity.java

package com.example.studyactivity;

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

public class MainActivity extends Activity {

	private Button mButton;
	private TextView mTextView;
	private int mTvNum = 1;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		mButton = (Button) findViewById(R.id.btnReturn);
		mTextView = (TextView) findViewById(R.id.tvNum1);
		mButton.setOnClickListener(new OnClickListener() {

			@Override
			public void onClick(View v) {
				Intent intent = new Intent(MainActivity.this, NewActivity.class);
				Bundle bundle = new Bundle();
				bundle.putInt("mTvNum", mTvNum);
				intent.putExtras(bundle);
				startActivity(intent);
			}
		});
	}

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		// Inflate the menu; this adds items to the action bar if it is present.
		getMenuInflater().inflate(R.menu.main, menu);
		return true;
	}
}

NewActivity.java

package com.example.studyactivity;

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

public class NewActivity extends Activity {
	private Button mButton;
	private int mTvNum;
	private TextView mTextView;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_new);
		mButton = (Button) findViewById(R.id.btnReturn);
		mTextView = (TextView) findViewById(R.id.tvNum1);
		Intent intent = getIntent();
		mTvNum = intent.getIntExtra("mTvNum", 0);
		mTextView.setText(Integer.toString(mTvNum + 1));
		mButton.setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View v) {
				NewActivity.this.finish();
			}
		});
	}
}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.studyactivity"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="15" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.example.studyactivity.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name="com.example.studyactivity.NewActivity" >
        </activity>
    </application>

</manifest>

新的內容並不多

一、添加新的Activity需要到AndroidManifest.xml裏註冊，這裏，我新加入的Activity名爲NewActivity，位於包com.example.studyactivity裏。所以在<application的子級添加

<activity android:name="com.example.studyactivity.NewActivity" >
        </activity>

二、跳轉Activity時需要使用到 意圖Intent,如此處:

Intent intent = new Intent(MainActivity.this, NewActivity.class);

startActivity(intent);

三、不同Activity之間傳遞參數，需要用到Bundle

Bundle bundle = new Bundle();
                bundle.putInt("mTvNum", mTvNum);
                intent.putExtras(bundle);

初步瞭解到，Bundle可以傳遞int類型與String類型的變量或者常量。