我的第一个Android

SayHello:

MainActivity.java

两种打开新的Activity的方法：传参和不传参

第一种方法：

import android.os.Bundle;
import android.app.Activity;
import android.text.Editable;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends Activity {
	private Button btnClick;
	private EditText etName;
	public static final String TAG = "MainActivity";

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);

		btnClick = (Button) findViewById(R.id.btnClick);
		etName = (EditText) findViewById(R.id.etName);
		btnClick.setOnClickListener(new ClickHandler());

	}

	class ClickHandler implements OnClickListener {

		@Override
		public void onClick(View v) {
			String name = etName.getText().toString();
			// Log.d(TAG,"Hello"+name);
			Toast.makeText(MainActivity.this, "你好" + name, Toast.LENGTH_LONG)
					.show();
		}

	}

}

</pre><pre name="code" class="html">第二种方法：

<pre name="code" class="html"><pre name="code" class="html">
import android.os.Bundle;
import android.app.Activity;
import android.text.Editable;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends Activity {
	private EditText etName;
	public static final String TAG = "MainActivity";

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);

		etName = (EditText) findViewById(R.id.etName);

	}
	
	public void sayHello(View view){
		String name = etName.getText().toString();
		System.out.println("nihao");
		Log.d(TAG, "nihao");
		Log.d(TAG,"hello"+view.getId());
		Toast.makeText(MainActivity.this, "Hello" + name, Toast.LENGTH_LONG)
				.show();
	}


}

</pre><span style="white-space:pre"> </span>activity_main.xml<p></p><p><span style="white-space:pre"></span></p><pre name="code" class="html"><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:background="@drawable/bg"
    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" >

    <TextView
        android:id="@+id/tvNamePrompt"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="130dp"
        android:text="@string/tvNamePrompt"
        android:textSize="20sp" />

    <EditText
        android:id="@+id/etName"
        android:drawableLeft="@drawable/name"
        android:drawablePadding="10dp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/tvNamePrompt"
        android:layout_below="@id/tvNamePrompt"
        android:layout_marginTop="25dp"
        android:ems="8" >

        <requestFocus />
    </EditText>

    <Button
        android:id="@+id/btnClick"
        android:background="@null"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/etName"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="24dp"
        android:text="@string/btnClick" />

</RelativeLayout>

</pre><span style="white-space:pre"></span>colors.xml<p></p><p></p><pre name="code" class="html"><?xml version="1.0" encoding="utf-8"?>
<resources>
    <color name="red">#ff0000</color>
    <color name="blue">#0000ff</color>
</resources>

</pre><span style="white-space:pre"> </span>dimens.xml<p></p><p></p><pre name="code" class="html"><resources>

    <!-- Default screen margins, per the Android Design guidelines. -->
    <dimen name="activity_horizontal_margin">16dp</dimen>
    <dimen name="activity_vertical_margin">16dp</dimen>

</resources>

</pre><pre name="code" class="html"><span style="white-space:pre">	</span>strings.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="app_name">SayHello</string>
    <string name="action_settings">Settings</string>
    <string name="tvNamePrompt">请输入你的姓名</string>
    <string name="btnClick">请点击我</string>

</resources>