Android 对话框 示例

书中这部分展示了4种Android对话框。

import android.app.Activity;
import android.app.AlertDialog;
import android.app.Dialog;
import android.app.ProgressDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class ActivityMain extends Activity {
    private static final int DIALOG1 = 1;
    private static final int DIALOG2 = 2;
    private static final int DIALOG4 = 4;
    private static final int DIALOG3 = 3;

    @Override
    protected Dialog onCreateDialog(int id) {
        switch (id) { //根据不同分支生成不同的对话框
        case DIALOG1:
            return buildDialog1(ActivityMain.this);

        case DIALOG2:
            return buildDialog2(ActivityMain.this);

        case DIALOG3:
            return buildDialog3(ActivityMain.this);
        case DIALOG4:
            return buildDialog4(ActivityMain.this);

        }
        return null;
    }
    //显示对话框之前调用的方法
    protected void onPrepareDialog(int id, Dialog dialog){
        if(id==DIALOG1){
            setTitle("测试");
        }
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.alert_dialog); //设置当前的显示

        Button button1 = (Button) findViewById(R.id.button1);
        button1.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                showDialog(DIALOG1); //设置单击后的事件
            }
        });

        Button buttons2 = (Button) findViewById(R.id.buttons2);
        buttons2.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                showDialog(DIALOG2);
            }
        });

        Button button3 = (Button) findViewById(R.id.button3);
        button3.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                showDialog(DIALOG3);
            }
        });
       
        Button button4 = (Button) findViewById(R.id.button4);
        button4.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                showDialog(DIALOG4);
            }
        });
    }

    private Dialog buildDialog1(Context context) {
        AlertDialog.Builder builder = new AlertDialog.Builder(context); //创建器
        builder.setIcon(R.drawable.alert_dialog_icon);
        builder.setTitle(R.string.alert_dialog_two_buttons_title);
        builder.setPositiveButton(R.string.alert_dialog_ok,
                new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int whichButton) {

                        setTitle("点击了对话框上的确定按钮");
                    }
                }); //确定按钮的定义和事件
        builder.setNegativeButton(R.string.alert_dialog_cancel,
                new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int whichButton) {

                        setTitle("点击了对话框上的取消按钮");
                    }
                });//取消按钮的定义和事件。
        return builder.create();

    }
    private Dialog buildDialog2(Context context) {
        AlertDialog.Builder builder = new AlertDialog.Builder(context); //下面都是从配置文件当中取出内容设置对话框属性。
        builder.setIcon(R.drawable.alert_dialog_icon);
        builder.setTitle(R.string.alert_dialog_two_buttons_msg);
        builder.setMessage(R.string.alert_dialog_two_buttons2_msg);
        builder.setPositiveButton(R.string.alert_dialog_ok,
                new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int whichButton) {

                        setTitle("点击了对话框上的确定按钮");
                    }
                });
        builder.setNeutralButton(R.string.alert_dialog_something,
                new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int whichButton) {

                        setTitle("点击了对话框上的进入详细按钮");
                    }
                });
        builder.setNegativeButton(R.string.alert_dialog_cancel,
                new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int whichButton) {

                        setTitle("点击了对话框上的取消按钮");
                    }
                });
        return builder.create();
    }

    private Dialog buildDialog3(Context context) {
        LayoutInflater inflater = LayoutInflater.from(this);
        final View textEntryView = inflater.inflate(
                R.layout.alert_dialog_text_entry, null); //还原配置文件到View对象
        AlertDialog.Builder builder = new AlertDialog.Builder(context);
        builder.setIcon(R.drawable.alert_dialog_icon);
        builder.setTitle(R.string.alert_dialog_text_entry);
        builder.setView(textEntryView); //设置显示样式
        builder.setPositiveButton(R.string.alert_dialog_ok,
                new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int whichButton) {
                        setTitle("点击了对话框上的确定按钮");
                    }
                });
        builder.setNegativeButton(R.string.alert_dialog_cancel,
                new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int whichButton) {
                        setTitle("点击了对话框上的取消按钮");
                    }
                });
        return builder.create();
    }
   
    //进度条对话框很简单
    private Dialog buildDialog4(Context context) {
        ProgressDialog dialog = new ProgressDialog(context);
        dialog.setTitle("正在下载歌曲");
        dialog.setMessage("请稍候……");
        return  dialog;
    }
}