Android 初体验

来源：互联网发布：microsoft软件有哪些编辑：程序博客网时间：2024/06/16 08:06

一年前学过一点点安卓，今天从头再来
首先模拟一个登录界面，写一个线性布局

activity_login.xml

<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:orientation="vertical"    tools:context=".LinearLayoutOneActivity" >    <LinearLayout android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:orientation="horizontal">        <TextView            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="帐号："/>        <EditText            android:id="@+id/name"            android:layout_height="wrap_content"            android:layout_width="match_parent"            />    </LinearLayout>    <LinearLayout android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:orientation="horizontal">        <TextView            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="密码："/>        <EditText            android:id="@+id/passwd"            android:layout_height="wrap_content"            android:layout_width="match_parent"            android:password="true"            />    </LinearLayout>    <LinearLayout        android:layout_width="match_parent"        android:layout_height="match_parent"        android:orientation="horizontal">        <Button            android:id="@+id/myFirstBbutton"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="open baidu"            android:onClick="clickButton"            />        <Button            android:id="@+id/mysecondBbutton"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="get input"            android:onClick="clickButton"            />        <Button            android:id="@+id/mythirdBbutton"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="open the windows"            android:onClick="clickButton"            />    </LinearLayout></LinearLayout>

布局中提供了两个输入框，三个按钮第一个按钮打开baidu首页，第二个按钮获取输入信息，第三个是打开新窗口
下面是java代码
MainActivity.java

package com.example.rhxy.myapplication;import android.content.Intent;import android.net.Uri;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.Menu;import android.view.MenuItem;import android.view.View;import android.widget.Button;import android.widget.EditText;import android.widget.Toast;public class MainActivity extends AppCompatActivity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_login);    }    public void clickButton(View v) {        int id = v.getId();        if(id==R.id.mysecondBbutton){            //建立对象            EditText name=(EditText) findViewById(R.id.name);            EditText passwd=(EditText) findViewById(R.id.passwd);            String namecent=name.getText().toString();            String pwdcent=passwd.getText().toString();            Toast.makeText(this,"center:"+namecent+"pwd:"+pwdcent,Toast.LENGTH_SHORT).show();        }        if(id==R.id.myFirstBbutton){            Uri uri = Uri.parse("http://www.baidu.com");            Intent it  = new Intent(Intent.ACTION_VIEW,uri);            startActivity(it);            Toast.makeText(this,"第一个按钮",Toast.LENGTH_LONG).show();        }        if(id==R.id.mythirdBbutton){            //创建一个窗体对象           /* Intent newWindow = new Intent();            newWindow.setClass(MainActivity.this, scendActivity.class);            startActivity(newWindow);*/            //创建一个窗体对象            Intent newWindow = new Intent();            newWindow.setClass(MainActivity.this, scendActivity.class);            startActivity(newWindow);        }    }    @Override    public boolean onCreateOptionsMenu(Menu menu) {        // Inflate the menu; this adds items to the action bar if it is present.        getMenuInflater().inflate(R.menu.menu_main, menu);        return true;    }    @Override    public boolean onOptionsItemSelected(MenuItem item) {        // Handle action bar item clicks here. The action bar will        // automatically handle clicks on the Home/Up button, so long        // as you specify a parent activity in AndroidManifest.xml.        int id = item.getItemId();        //noinspection SimplifiableIfStatement        if (id == R.id.action_settings) {            Toast.makeText(this,"setting",Toast.LENGTH_LONG).show();            return true;        }        if (id == R.id.action_help) {            Toast.makeText(this,"help",Toast.LENGTH_LONG).show();            return true;        }        return super.onOptionsItemSelected(item);    }}

second.java 一时手快，下面拼错了。

package com.example.rhxy.myapplication;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.view.Menu;import android.view.MenuItem;import android.view.View;import android.widget.EditText;import android.widget.Toast;public class scendActivity extends AppCompatActivity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_zh);    }    @Override    public boolean onCreateOptionsMenu(Menu menu) {        // Inflate the menu; this adds items to the action bar if it is present.        getMenuInflater().inflate(R.menu.menu_main, menu);        return true;    }}

值得注意的是，在打开新窗口的时候要在配置文件中，添加 activity

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.example.rhxy.myapplication" >    <application        android:allowBackup="true"        android:icon="@mipmap/ic_launcher"        android:label="@string/app_name"        android:theme="@style/AppTheme" >        <activity            android:name=".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=".scendActivity"            android:label="@string/app_name" >            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>***    </application></manifest>

ps:Android Studio 确实比eclipse感觉舒服

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