Android 程式开发：（1）详解Activity —— 1.4显示“普通”对话框_Android

Android 程式开发：（一）详解Activity —— 1.4显示“普通”对话框

? ? 有的时候，可能需要弹出一个对话框，以便从用户的输入来获取某些确认信息。这种情况下，可以重写Activity基类中的受保护方法（protected）onCreateDialog()。

??? 1.创建一个名为Dialog的工程。

??? 2.main.xml中的代码。

[java]?view plaincopy

<?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中的代码。

[java]?view plaincopy

package?net.horsttnann.Dialog;??
??
import?android.app.Activity;??
import?android.app.AlertDialog;??
import?android.app.Dialog;??
import?android.content.DialogInterface;??
import?android.os.Bundle;??
import?android.view.View;??
import?android.widget.Toast;??
??
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;??
????}??
}??

??? 4.调试。

??? 点击按钮弹出对话框，在CheckBox上面打勾，就会弹出一个Toast提示，显示选中物件的文本信息。点击“OK”或“Cancel”按钮会使对话框消失。

效果图：

更多信息请查看?java进阶网?http://www.javady.com