吴裕雄--天生自然ANDROID开发学习：2.5.9 AlertDialog(对话框)详解

官方文档：AlertDialog:http://androiddoc.qiniudn.com/reference/android/app/AlertDialog.html

1.基本使用流程
Step 1：创建AlertDialog.Builder对象；
Step 2：调用setIcon()设置图标，setTitle()或setCustomTitle()设置标题；
Step 3：设置对话框的内容：setMessage()还有其他方法来指定显示的内容；
Step 4：调用setPositive/Negative/NeutralButton()设置：确定，取消，中立按钮；
Step 5：调用create()方法创建这个对象，再调用show()方法将对话框显示出来；

核心代码：

MainActivity.java：

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private Button btn_dialog_one;
    private Button btn_dialog_two;
    private Button btn_dialog_three;
    private Button btn_dialog_four;

    private Context mContext;
    private boolean[] checkItems;

    private AlertDialog alert = null;
    private AlertDialog.Builder builder = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mContext = MainActivity.this;
        bindView();


    }

    private void bindView() {
        btn_dialog_one = (Button) findViewById(R.id.btn_dialog_one);
        btn_dialog_two = (Button) findViewById(R.id.btn_dialog_two);
        btn_dialog_three = (Button) findViewById(R.id.btn_dialog_three);
        btn_dialog_four = (Button) findViewById(R.id.btn_dialog_four);
        btn_dialog_one.setOnClickListener(this);
        btn_dialog_two.setOnClickListener(this);
        btn_dialog_three.setOnClickListener(this);
        btn_dialog_four.setOnClickListener(this);
    }


    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            //普通对话框
            case R.id.btn_dialog_one:
                alert = null;
                builder = new AlertDialog.Builder(mContext);
                alert = builder.setIcon(R.mipmap.ic_icon_fish)
                        .setTitle("系统提示：")
                        .setMessage("这是一个最普通的AlertDialog,
带有三个按钮，分别是取消，中立和确定")
                        .setNegativeButton("取消", new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                                Toast.makeText(mContext, "你点击了取消按钮~", Toast.LENGTH_SHORT).show();
                            }
                        })
                        .setPositiveButton("确定", new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                                Toast.makeText(mContext, "你点击了确定按钮~", Toast.LENGTH_SHORT).show();
                            }
                        })
                        .setNeutralButton("中立", new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                                Toast.makeText(mContext, "你点击了中立按钮~", Toast.LENGTH_SHORT).show();
                            }
                        }).create();             //创建AlertDialog对象
                alert.show();                    //显示对话框
                break;
            //普通列表对话框
            case R.id.btn_dialog_two:
                final String[] lesson = new String[]{"语文", "数学", "英语", "化学", "生物", "物理", "体育"};
                alert = null;
                builder = new AlertDialog.Builder(mContext);
                alert = builder.setIcon(R.mipmap.ic_icon_fish)
                        .setTitle("选择你喜欢的课程")
                        .setItems(lesson, new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                                Toast.makeText(getApplicationContext(), "你选择了" + lesson[which], Toast.LENGTH_SHORT).show();
                            }
                        }).create();
                alert.show();
                break;
            //单选列表对话框
            case R.id.btn_dialog_three:
                final String[] fruits = new String[]{"苹果", "雪梨", "香蕉", "葡萄", "西瓜"};
                alert = null;
                builder = new AlertDialog.Builder(mContext);
                alert = builder.setIcon(R.mipmap.ic_icon_fish)
                        .setTitle("选择你喜欢的水果，只能选一个哦~")
                        .setSingleChoiceItems(fruits, 0, new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                                Toast.makeText(getApplicationContext(), "你选择了" + fruits[which], Toast.LENGTH_SHORT).show();
                            }
                        }).create();
                alert.show();
                break;
            //多选列表对话框
            case R.id.btn_dialog_four:
                final String[] menu = new String[]{"水煮豆腐", "萝卜牛腩", "酱油鸡", "胡椒猪肚鸡"};
                //定义一个用来记录个列表项状态的boolean数组
                checkItems = new boolean[]{false, false, false, false};
                alert = null;
                builder = new AlertDialog.Builder(mContext);
                alert = builder.setIcon(R.mipmap.ic_icon_fish)
                        .setMultiChoiceItems(menu, checkItems, new DialogInterface.OnMultiChoiceClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which, boolean isChecked) {
                                checkItems[which] = isChecked;
                            }
                        })
                        .setPositiveButton("确定", new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                                String result = "";
                                for (int i = 0; i < checkItems.length; i++) {
                                    if (checkItems[i])
                                        result += menu[i] + " ";
                                }
                                Toast.makeText(getApplicationContext(), "客官你点了:" + result, Toast.LENGTH_SHORT).show();
                            }
                        })
                        .create();
                alert.show();
                break;
        }
    }
}

3.通过Builder的setView()定制显示的AlertDialog

关键代码：

首先是两种不同按钮的selctor的drawable文件：

btn_selctor_exit.xml：

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_pressed="true" android:drawable="@mipmap/iv_icon_exit_pressed"/>
    <item android:drawable="@mipmap/iv_icon_exit_normal"/>
</selector>
btn_selctor_choose.xml：

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_pressed="true" android:drawable="@mipmap/bg_btn_pressed"/>
    <item android:drawable="@mipmap/bg_btn_normal"/>
</selector>
接着是自定义的Dialog布局：view_dialog_custom.xml：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/RelativeLayout1"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <RelativeLayout
        android:id="@+id/titlelayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:background="#53CC66"
        android:padding="5dp">

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_centerVertical="true"
            android:text="提示信息"
            android:textColor="#ffffff"
            android:textSize="18sp"
            android:textStyle="bold" />

        <Button
            android:id="@+id/btn_cancle"
            android:layout_width="30dp"
            android:layout_height="30dp"
            android:layout_alignParentRight="true"
            android:background="@drawable/btn_selctor_exit" />

    </RelativeLayout>


    <LinearLayout
        android:id="@+id/ly_detail"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/titlelayout"
        android:layout_centerInParent="true"
        android:orientation="vertical">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="10dp"
            android:layout_marginTop="20dp"
            android:text="通过setView()方法定制AlertDialog"
            android:textColor="#04AEDA"
            android:textSize="18sp" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="10dp"
            android:layout_marginTop="10dp"
            android:text="作者:Coder-pig"
            android:textColor="#04AEDA"
            android:textSize="18sp" />
    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/ly_detail"
        android:layout_marginTop="10dp"
        android:orientation="horizontal">

        <Button
            android:id="@+id/btn_blog"
            android:layout_width="match_parent"
            android:layout_height="40dp"
            android:layout_margin="5dp"
            android:layout_weight="1"
            android:background="@drawable/btn_selctor_choose"
            android:text="访问博客"
            android:textColor="#ffffff"
            android:textSize="20sp" />

        <Button
            android:id="@+id/btn_close"
            android:layout_width="match_parent"
            android:layout_height="40dp"
            android:layout_margin="5dp"
            android:layout_weight="1"
            android:background="@drawable/btn_selctor_choose"
            android:text="关闭"
            android:textColor="#ffffff"
            android:textSize="20sp" />

    </LinearLayout>

</RelativeLayout>  
最后是MainActivity.java：

public class MainActivity extends AppCompatActivity {

    private Button btn_show;
    private View view_custom;
    private Context mContext;
    private AlertDialog alert = null;
    private AlertDialog.Builder builder = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mContext = MainActivity.this;
        btn_show = (Button) findViewById(R.id.btn_show);

        //初始化Builder
        builder = new AlertDialog.Builder(mContext);

        //加载自定义的那个View,同时设置下
        final LayoutInflater inflater = MainActivity.this.getLayoutInflater();
        view_custom = inflater.inflate(R.layout.view_dialog_custom, null,false);
        builder.setView(view_custom);
        builder.setCancelable(false);
        alert = builder.create();

        view_custom.findViewById(R.id.btn_cancle).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                alert.dismiss();
            }
        });

        view_custom.findViewById(R.id.btn_blog).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(getApplicationContext(), "访问博客", Toast.LENGTH_SHORT).show();
                Uri uri = Uri.parse("http://blog.csdn.net/coder_pig");
                Intent intent = new Intent(Intent.ACTION_VIEW, uri);
                startActivity(intent);
                alert.dismiss();
            }
        });

        view_custom.findViewById(R.id.btn_close).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(getApplicationContext(), "对话框已关闭~", Toast.LENGTH_SHORT).show();
                alert.dismiss();
            }
        });

        btn_show.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                alert.show();
            }
        });
    }
}