2017-2018-2 20165312 Experimental Report on Android program design

2017-2018-2 20165312 Experiment four "Android programming" experimental report install Android studio and install Android Studio with Hello World test and debug program

Can refer to Lou Teacher's blog Android Development Simple tutorial or reference "Java and Android Development Learning Guide" chapter 24th, there are detailed steps, step by step is very simple ~

After you create a new project project, the Project window has two main nodes:app and Gradle Scripts. The app node contains all the components in the application, and we use the app primarily when we write the program. There are 3 nodes under the app node

• manifestsContains a AndroidManifest.xml manifest file
• javaContains all of the Java applications and test classes
• resContains the resource files, and there are some directories in this directory:
  • drawable
  • layout
  • menu
  • values
  • mipmap

The above is a preliminary understanding of the construction of Android studio

Do Hello World test

Steps:

• Open itlayout->activity_main.xml
• Modifyandroid:text

<?xml version="1.0" encoding="utf-8"?><android.support.constraint.ConstraintLayout    xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    xmlns:app="http://schemas.android.com/apk/res-auto"    android:layout_width="match_parent"    android:layout_height="match_parent"    tools:context="com.example.lenovo.myapplication.MainActivity">    <TextView        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="       Hello World! 20165312曹歌       Hello World! 20165311李嘉昕       Hello World! 20165313张晨晖"        app:layout_constraintBottom_toBottomOf="parent"        app:layout_constraintLeft_toLeftOf="parent"        app:layout_constraintRight_toRightOf="parent"        app:layout_constraintTop_toTopOf="parent" /></android.support.constraint.ConstraintLayout>

• RunMainActivity.java

To debug a program log message

The simplest way to debug an application is to use log messages. During the development process, you can see the Android Ddms view at the bottom of the home screen of Android studio. With regard to LogCat, messages of different log levels are displayed in different colors, each message has a label, which makes it easy to find a message.

Tracking Program

• Set breakpoints on any line
• Open Run->Debug to Debug program
• Enter code, browse variables in the Debug bar below Android Studio

• Specific debug code method operations personally think is the same as the idea debug code method ~

Second, activity testing

Activity is a window that contains a user interface component, a typical Android application that starts with an activity. The first window created by an application is called the main activity.appliaction元素定义两个活动，其中之一使用intent-filter元素声明的为主活动。

Starting an activity involves instantiating the active class and invoking the life cycle method:

• onCreat()
• onStart()
• onResume()
• onPause()
• onStop()
• onRestart()
• onDestory()

Each control file Activity requires a corresponding startup program file (. java) and the corresponding layout file (. xml)

Build the project, run the textbook related code

Link to the relevant code of the textbook

Create thirdactivity, display your own number in thirdactivity, modify the code to let mainactivity start thirdactivity

Steps:

• In the AndroidManifest.xml manifest file, add aactivity

      <activity        android:name=".ThirdActivity">    </activity>

• Add a ThirdActivity.java file

  package cn.edu.besti.is.cg;import android.app.Activity;import android.os.Bundle;public class ThirdActivity extends Activity {@Overrideprotected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_third);}}

• Add a third_activity.xml file

<RelativeLayout 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"    tools:context=".ThirdActivity">    <TextView        android:id="@+id/textView1"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="20165312曹歌"/></RelativeLayout>

• Modify MainActivity.java to make it self-startingThirdActivity.java

Package Cn.edu.besti.is.cg;import Android.app.activity;import Android.content.intent;import android.os.Bundle; Import Android.view.menu;import Android.view.motionevent;import Android.view.view;import Android.view.view.ontouchlistener;import android.widget.textview;import static cn.edu.besti.is.cg.r.id.textview1; public class Mainactivity extends Activity implements Ontouchlistener {@Override protected void onCreate (Bun        Dle savedinstancestate) {super.oncreate (savedinstancestate);        Setcontentview (R.layout.activity_main);        TextView TV = (TextView) Findviewbyid (TEXTVIEW1);    Tv.setontouchlistener (this); } @Override Public boolean Oncreateoptionsmenu (Menu menu) {//Inflate the menu, this adds items to the Actio        n Bar if it//is present.        Getmenuinflater (). Inflate (R.menu.menu_main, menu);    return true; } @Override public boolean OnTouch (View arg0, motionevent event) {Intent Intent = new Intent (This, thirDactivity.class);        Intent.putextra ("message", "Message from First screen");        StartActivity (Intent);    return true; }}

Third, UI testing

The so-called UI, is to build the user cross for the main activity (users interface)

Modify the code to let the toast message display its own learning number information

Toast: A consumer pop-up dialog box that displays a message as feedback to the user, and toast does not replace the current content.

Modify Activity_main.xml

<?xml version="1.0" encoding="utf-8"?><android.support.constraint.ConstraintLayout    xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    xmlns:app="http://schemas.android.com/apk/res-auto"    android:layout_width="match_parent"    android:layout_height="match_parent"    tools:context="cn.edu.besti.is.cg.ui.MainActivity">    <TextView        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="欢迎来到20165312的世界"        app:layout_constraintBottom_toBottomOf="parent"        app:layout_constraintLeft_toLeftOf="parent"        app:layout_constraintRight_toRightOf="parent"        app:layout_constraintTop_toTopOf="parent" /></android.support.constraint.ConstraintLayout>

Modify Mainactivity.java

package cn.edu.besti.is.cg.ui;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.widget.Toast;public class MainActivity extends AppCompatActivity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        Toast toast = Toast.makeText(MainActivity.this, "20165312曹歌", Toast.LENGTH_LONG);        toast.show();    }}

Four, layout test

Some of the layouts in Android:

• LinearLayoutA layout that aligns all the child views in the same direction (horizontal or vertical)
• RelativeLayoutArranges one of his layouts according to the position of one or more sibling views of the child view
• FrameLayoutA layout that places each child view at the top of another child view
• TableLayoutA layout that organizes a child view by rows and columns
• GridLayoutA layout that places a child view in a grid

Modify the layout so that the P290 page interface is different from the textbook

Modifyactivity_main.xml

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:orientation="vertical"    android:layout_width="match_parent"    android:layout_height="match_parent">    <Button android:text="Button1"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_marginTop="30dp"        android:layout_marginLeft="100dp" />    <ImageButton        android:src="@android:drawable/btn_star_big_on"        android:alpha="0.45"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_marginTop="200dp"        android:layout_marginLeft="300dp" /></FrameLayout>

V. Event processing test run textbook code

Mainactivity.java

  Package Cn.edu.besti.is.cg.cellview;import android.app.activity;import Android.graphics.color;import Android.os.bundle;import Android.view.menu;import Android.view.view;public class Mainactivity extends Activity {int Co    unter = 0;            int[] Colors = {color.black, Color.Blue, Color.cyan, Color.dkgray, Color.gray, Color.green, Color.ltgray,    Color.magenta, Color.Red, Color.White, color.yellow};        @Override protected void OnCreate (Bundle savedinstancestate) {super.oncreate (savedinstancestate);    Setcontentview (R.layout.activity_main);  } @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;        public void ChangeColor (view view) {if (counter = = colors.length) {counter = 0;    } view.setbackgroundcolor (colors[counter++]); }}

Activity_main.xml

<?xml version="1.0" encoding="utf-8"?><RelativeLayout    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"    tools:context=".MainActivity">    <AnalogClock        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignParentTop="true"        android:layout_centerHorizontal="true"        android:layout_marginTop="90dp"        android:id="@+id/analogClock1"        android:onClick="changeColor" /></RelativeLayout>

The problems encountered in the experiment appeared Executing tasks: app:assembleDebugThe problem, after Baidu found Androidstudio appeared executing tasks:app:assembleDebug.

build.gradle(module:app)in the file

testApplicationId“com.cn.skypiea.test" testInstrumentationRunner "android.test.InstrumentationTestRunner"

After you have commented, you can package it successfully.

Appear Execution failed for task ‘:app:preDebugAndroidTestBuildThe problem, Baidu found a blog post, Build->Rebuild ProjectYou can then run the problem of R Red

In fact, I think R is very iffy, I have tried several solutions, the first time I rerun and then R is automatically not marked red, anyway is very strange; the second time I changed package the content of the red and then it is OK, and the third time I took a Ctrl+Enter new thing on the right, so more try ...

Finally I found a blog in Android studio R into Red Studio R into red for everyone's reference.

2017-2018-2 20165312 Experimental Report on Android program design