AlertDialog使用实例

创建项目AlertDialogDemo如图:

 AlertDialogDemo.java文件代码如下：

 

package zerone.AlertDialogDemo;

  

import android.app.Activity;

  

public class AlertDialogDemo extends Activity {

    /** Called when the activity is first created. */

    final int DIALOG_WELCOME = 1;

    private Button btn_alert;

    @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);

        btn_alert=(Button)findViewById(R.id.btn_dialog);

        btn_alert.setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View v) {

                showDialog(DIALOG_WELCOME);//调用onCreateDialog

            }

        });

    }

      

    @Override

    protected Dialog onCreateDialog(int id, Bundle args) {

        switch (id) {

        case DIALOG_WELCOME:

            return new AlertDialog.Builder(AlertDialogDemo.this)

            .setTitle("欢迎").setMessage("欢迎使用本程序")

            .setIcon(android.R.drawable.ic_dialog_info)

            .setPositiveButton("确定", new OnClickListener() {

                @Override

                public void onClick(DialogInterface dialog, int which) {

                    Toast.makeText(AlertDialogDemo.this,"点击\"确定\"按钮后", Toast.LENGTH_SHORT).show();

                }

            }).create();

        default:

            return null;

        }

    }

      

}

main.xml代码如下：

<?xml version="1.0" encoding="utf-8"?>
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:orientation="vertical"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    > 
<TextView      
android:layout_width="fill_parent"     android:layout_height="wrap_content"     android:text="@string/app_title"    /> 
<Button   
android:id="@+id/btn_dialog"   
android:layout_width="fill_parent"   android:layout_height="wrap_content"   android:text="弹出"/> </LinearLayout>