Android Quick Start

Project Source Download

Https://github.com/Wang-Jun-Chao/AndroidProjects

Directory structure for Android projects

Activity: The interface that is displayed when the application is opened

SRC: Project Code

R.java: Resource IDs for all resource files in the project

Android.jar:Android jar Package, import this package to use the Android API

Libs: Importing third party jar packages

Assets: Store resource files, such as MP3, video files

Bin: Store the compiled and packaged files

Res: Store resource files, all resource files stored in this folder will generate resource IDs

Drawable: Storing picture resources

Layout: Store the layout file, assign the layout file to the activity through the resource ID, and the interface will show the layout of the layout file definition

Menu: Define style for menus

Strings.xml: Storing string resources, each resource will have a resource ID

Android configuration file (manifest file)

Specify the package name for the application

package="com.itheima.helloworld"

Data/data/com.itheima.helloworld (the package name specified in the code above)

Application generated files are stored under this path

Android's four components need to be configured in the manifest file before use

The configuration is effective for the entire application

The configuration is in effect for the activity

DDMS

Dalvik Debug Monitor Service

Dalvik Debugging and Monitoring service

The common ADB directive

Android Debug Bridge: Android Debugging Bridges

ADB start-server: Start adb process

ADB kill-server: Killing the ADB process

ADB devices: View the device that is currently connected to the development environment, and this command can also start the ADB process

ADB install xxx.apk: Installing APK to Simulator

ADB Uninstall Package Name: Removing the application in the simulator

ADB shell: Go to linux command line

PS: View the running process

LS: View the file structure under the current directory

Netstat-ano: View the process of seizing ports

Phone Dialer

Function: The user enters a number, clicks the call button, starts the system to call the application to dial out the number

1. Define Layout

The component must be set to a wide height, otherwise it cannot be compiled

android:layout_width="wrap_content"
android:layout_height="wrap_content"

If you want to manipulate a component in Java code, the component needs to set the ID so that you can get the component by ID in your code

android:id="@+id/et_phone"

2. Set click on the button to listen

Set the button to listen

// Get the button object by id
Button bt_call = (Button) findViewById (R.id.bt_call);
// Set the button to click
bt_call.setOnClickListener (new MyListener ());

3. Get the number entered by the user

//Get the number entered by the user, first get the input box component
        EditText et_phone = (EditText) findViewById(R.id.et_phone);
        String phone = et_phone.getText().toString();

4. Call the number out.

Android system based on the action mechanism to invoke the application of the system, you tell the system what you want to do, the system will be able to do this action application to you, without this application, will throw the exception

Set the action to inform the system by intent

//Dial out the number
     // First create an intent object
     Intent intent = new Intent ();
     // Set the action and call
     intent.setAction (Intent.ACTION_CALL);
     intent.setData (Uri.parse ("tel:" + phone));
     // tell the system
    startActivity(intent);

Add permissions

<uses-permission android:name="android.permission.CALL_PHONE"/>

Four ways to spell the Click event

First Kind

Define a MyListener implementation Onclicklistener interface

Button bt1 = (Button) findViewById(R.id.bt1);
bt1.setOnClickListener(new MyListener());

Second Kind

Define an anonymous inner class to implement the Onclicklistener interface

Button bt2 = (Button) findViewById(R.id.bt2);
bt2.setOnClickListener(new OnClickListener() {

    @Override
    public void onClick(View v) {
        System.out.println("第二种");

    }
});

Third Kind

Let the current activity implement the Onclicklistener interface

Button bt3 = (Button) findViewById(R.id.bt3);
bt3.setOnClickListener(this);

Fourth Kind

Set the OnClick property to the button node.

android:onClick="click"

Then define a method in the activity with the same name as the property value

public void click(View v){
    System.out.println("第四种");
}

SMS Transmitter

Function: User input number and SMS content, click send button, call SMS API to send SMS to the specified number

1. Define Layout

Tips for entering boxes

android:hint="please input the number"

2. Complete the Click event

Set the OnClick property for the button component first

onclick= "Send"

Define this method in the activity

public void Send (View v) {}

3. Get the number and content entered by the user

EditText et_phone = (EditText) findViewById(R.id.et_phone);
    EditText et_content = (EditText) findViewById(R.id.et_content);
    String phone = et_phone.getText().toString();
    String content = et_content.getText().toString();

4. Invoke API to send SMS

// Call the API for sending SMS
     SmsManager sm = SmsManager.getDefault ();

     //send messages sm.sendTextMessage(phone, null, content, null, null);

* Add Permissions

<uses-permission android:name="android.permission.SEND_SMS"/>

* If the message is too long, you need to split

List<String> smss = sm.divideMessage(content);

More Wonderful content: http://www.bianceng.cnhttp://www.bianceng.cn/OS/extra/