Android開發入門（一）詳解活動 1.4 顯示普通對話框

有的時候，可能需要彈出一個對話框，以便從用戶的輸入來獲取某些確認信息。這種情況下，可以重寫 Activity基類中的受保護方法（protected）onCreateDialog()。

1. 創建一個工程：Dialog。

2. main.xml中的代碼。

<?xml version="1.0" encoding="utf-8"?>     
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 
  
    android:orientation="vertical" >     
             
<Button     
    android:id="@+id/btn_dialog" 
    android:layout_width="fill_parent"  
    android:layout_height="wrap_content" 
    android:text="Click to display a dialog" 
    android:onClick="onClick" />     
          
</LinearLayout>

3. DialogActivity.java中的代碼。

public class 

DialogActivity extends Activity {     
    CharSequence[] items = { "Google", "Apple", "Microsoft" };     
    boolean[] itemsChecked = new boolean[items.length];     
         
    /** Called when the activity is first created. */ 
    @Override 
    public void onCreate(Bundle savedInstanceState) {     
        super.onCreate(savedInstanceState);     
        setContentView(R.layout.main);     
    }     
         
    public void onClick(View v) {     
        showDialog(0);     
    }     
         
    @Override 
    protected Dialog onCreateDialog(int id) {     
        switch (id) {     
        case 0:     
            return new AlertDialog.Builder(this)     
                    .setIcon(R.drawable.ic_launcher)     
                    .setTitle("This is a dialog with some simple text...")     
                    .setPositiveButton("OK",     
                            new DialogInterface.OnClickListener() {     
                                public void onClick(DialogInterface dialog,     
                                        int whichButton) {     
                                    Toast.makeText(getBaseContext(),     
                                            "OK clicked!", Toast.LENGTH_SHORT)     
                                            .show();     
                                }     
                            })     
                    .setNegativeButton("Cancel",     
                            new DialogInterface.OnClickListener() {     
                                public void onClick(DialogInterface dialog,     
                                        int whichButton) {     
                                    Toast.makeText(getBaseContext(),     
                                            "Cancel clicked!",     
                                            Toast.LENGTH_SHORT).show();     
                                }     
                            })     
                    .setMultiChoiceItems(items, itemsChecked,     
                            new DialogInterface.OnMultiChoiceClickListener() {     
                                public void onClick(DialogInterface dialog,     
                                        int which, boolean isChecked) {     
                                    Toast.makeText(     
                                            getBaseContext(),     
                                            items[which]     
                                                    + (isChecked ? " checked!" 
                                                            : " unchecked!"),     
                                            Toast.LENGTH_SHORT).show();     
         
                                }     
                            }).create();     
        }     
        return null;     
    }     
}