调用另一个Activity-白红宇

调用另一个Activity

阅读量：6263 次

发布时间：2019-06-22

本文共 3628 字，大约阅读时间需要 12 分钟。

1、创建主Activity

使用Eclipse新建项目MyFirstApp,UI布局如下：

[html]

<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"

android:orientation="horizontal"

tools:context=".MainActivity">

<EditText

android:id="@+id/et_message"

android:layout_height="wrap_content"

android:layout_width="0dp"

android:layout_weight="1"

android:hint="@string/input_here"/>

<Button

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="@string/click"

android:onClick="sendMessage"/>

</LinearLayout>

注意通过权重来分配尺寸的方式

组件1：

[html]

android:layout_width="0dp"

android:layout_weight="1"

组件2：

[html]

android:layout_width="wrap_content"

2、在主类中指定onclick所对应的sendMessage方法

[java]

package com.lujinhong.androidtraningmyfirstapp;

import android.os.Bundle;

import android.app.Activity;

import android.content.Intent;

import android.view.Menu;

import android.view.View;

import android.widget.EditText;

public class MainActivity extends Activity{

public final static String EXTRA_MESSAGE="com.lujinhong.myfirstapp.MESSAGE";

@Override

protected void onCreate(Bundle savedInstanceState){

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

}

@Override

public boolean onCreateOptionsMenu(Menu menu){

// Inflate themenu; this adds items to the action bar if it is present.

getMenuInflater().inflate(R.menu.main, menu);

return true;

}

public void sendMessage(View v){

EditText et_message=(EditText)this.findViewById(R.id.et_message);

String message= et_message.getText().toString().trim();

Intent intent= new Intent(this,DisplayMessageActivity.class);

intent.putExtra(EXTRA_MESSAGE, message);

this.startActivity(intent);

}

}

（1）关于intent

An isan object that provides runtime binding between separate components (such astwo activities). The representsan app’s "intent to do something." You can use intents for a widevariety of tasks, but most often they’re used to startanother activity.

（2）调用另一个activity的步骤：

l 首先取得editText中的文字

[java]