AlertDialog的构造方法全部是Protected的，所以不能直接通过new一个AlertDialog来创建出一个AlertDialog。
要创建一个AlertDialog，就要用到AlertDialog.Builder中的create()方法。
使用AlertDialog.Builder创建对话框需要了解以下几个方法：
setTitle ：为对话框设置标题
setIcon ：为对话框设置图标
setMessage：为对话框设置内容
setView ： 给对话框设置自定义样式
setItems ：设置对话框要显示的一个list，一般用于显示几个命令时
setMultiChoiceItems ：用来设置对话框显示一系列的复选框
setNeutralButton ：普通按钮
setPositiveButton ：给对话框添加"Yes"按钮
setNegativeButton ：对话框添加"No"按钮
create ： 创建对话框
show ：显示对话框
一、简单的AlertDialog
下面，创建一个简单的ALertDialog并显示它：
public class Dialog_AlertDialogDemoActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Dialog alertDialog = new AlertDialog.Builder(this).
setTitle("对话框的标题").
setMessage("对话框的内容").
setIcon(R.drawable.ic_launcher).
create();
alertDialog.show();
}
}
二、带按钮的AlertDialog
上面的例子很简单，下面我们在这个AlertDialog上面加几个Button，实现删除操作的提示对话框
public class Dialog_AlertDialogDemoActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Dialog alertDialog = new AlertDialog.Builder(this).
setTitle("确定删除？").
setMessage("您确定删除该条信息吗？").
setIcon(R.drawable.ic_launcher).
setPositiveButton("确定", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
}
}).
setNegativeButton("取消", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
}
}).
setNeutralButton("查看详情", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
}
}).
create();
alertDialog.show();
}
}
public class Dialog_AlertDialogDemoActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Dialog alertDialog = new AlertDialog.Builder(this).
setTitle("确定删除？").
setMessage("您确定删除该条信息吗？").
setIcon(R.drawable.ic_launcher).
setPositiveButton("确定", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
}
}).
setNegativeButton("取消", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
}
}).
setNeutralButton("查看详情", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
}
}).
create();
alertDialog.show();
}
}在这个例子中，我们定义了三个按钮，分别是"Yes"按钮，"No"按钮以及一个普通按钮，每个按钮都有onClick事件，TODO的地方可以放点了按钮之后想要做的一些处理
看一下运行结果：
可以看到三个按钮添加到了AlertDialog上，三个没有添加事件处理的按钮，点了只是关闭对话框，没有任何其他操作。
三、类似ListView的AlertDialog
用setItems(CharSequence[] items, final OnClickListener listener)方法来实现类似ListView的AlertDialog
第一个参数是要显示的数据的数组，第二个参数是点击某个item的触发事件
public class Dialog_AlertDialogDemoActivity extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); final String[] arrayFruit = new String[] { "苹果", "橘子", "草莓", "香蕉" }; Dialog alertDialog = new AlertDialog.Builder(this). setTitle("你喜欢吃哪种水果？"). setIcon(R.drawable.ic_launcher) .setItems(arrayFruit, new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { Toast.makeText(Dialog_AlertDialogDemoActivity.this, arrayFruit[which], Toast.LENGTH_SHORT).show(); } }). setNegativeButton("取消", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { } }). create(); alertDialog.show(); } } public class Dialog_AlertDialogDemoActivity extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); final String[] arrayFruit = new String[] { "苹果", "橘子", "草莓", "香蕉" }; Dialog alertDialog = new AlertDialog.Builder(this). setTitle("你喜欢吃哪种水果？"). setIcon(R.drawable.ic_launcher) .setItems(arrayFruit, new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { Toast.makeText(Dialog_AlertDialogDemoActivity.this, arrayFruit[which], Toast.LENGTH_SHORT).show(); } }). setNegativeButton("取消", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { // TODO Auto-generated method stub } }). create(); alertDialog.show(); }
}运行结果如下：
四、类似RadioButton的AlertDialog
用setSingleChoiceItems(CharSequence[] items, int checkedItem, final OnClickListener listener)方法来实现类似RadioButton的AlertDialog
第一个参数是要显示的数据的数组，第二个参数是初始值（初始被选中的item），第三个参数是点击某个item的触发事件
在这个例子里面我们设了一个selectedFruitIndex用来记住选中的item的index
public class Dialog_AlertDialogDemoActivity extends Activity { private int selectedFruitIndex = 0; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); final String[] arrayFruit = new String[] { "苹果", "橘子", "草莓", "香蕉" }; Dialog alertDialog = new AlertDialog.Builder(this). setTitle("你喜欢吃哪种水果？"). setIcon(R.drawable.ic_launcher) .setSingleChoiceItems(arrayFruit, 0, new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { selectedFruitIndex = which; } }). setPositiveButton("确认", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { Toast.makeText(Dialog_AlertDialogDemoActivity.this, arrayFruit[selectedFruitIndex], Toast.LENGTH_SHORT).show(); } }). setNegativeButton("取消", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { } }). create(); alertDialog.show(); } } public class Dialog_AlertDialogDemoActivity extends Activity { private int selectedFruitIndex = 0; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); final String[] arrayFruit = new String[] { "苹果", "橘子", "草莓", "香蕉" }; Dialog alertDialog = new AlertDialog.Builder(this). setTitle("你喜欢吃哪种水果？"). setIcon(R.drawable.ic_launcher) .setSingleChoiceItems(arrayFruit, 0, new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { selectedFruitIndex = which; } }). setPositiveButton("确认", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { Toast.makeText(Dialog_AlertDialogDemoActivity.this, arrayFruit[selectedFruitIndex], Toast.LENGTH_SHORT).show(); } }). setNegativeButton("取消", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { } }). create(); alertDialog.show(); } }
运行结果如下：
五、类似CheckBox的AlertDialog
用setMultiChoiceItems(CharSequence[] items, boolean[] checkedItems, final OnMultiChoiceClickListener listener)方法来实现类似CheckBox的AlertDialog
第一个参数是要显示的数据的数组，第二个参数是选中状态的数组，第三个参数是点击某个item的触发事件
public class Dialog_AlertDialogDemoActivity extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); final String[] arrayFruit = new String[] { "苹果", "橘子", "草莓", "香蕉" }; final boolean[] arrayFruitSelected = new boolean[] {true, true, false, false}; Dialog alertDialog = new AlertDialog.Builder(this). setTitle("你喜欢吃哪种水果？"). setIcon(R.drawable.ic_launcher) .setMultiChoiceItems(arrayFruit, arrayFruitSelected, new DialogInterface.OnMultiChoiceClickListener() { @Override public void onClick(DialogInterface dialog, int which, boolean isChecked) { arrayFruitSelected[which] = isChecked; } }). setPositiveButton("确认", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { StringBuilder stringBuilder = new StringBuilder(); for (int i = 0; i < arrayFruitSelected.length; i++) { if (arrayFruitSelected == true) { stringBuilder.append(arrayFruit + "、"); } } Toast.makeText(Dialog_AlertDialogDemoActivity.this, stringBuilder.toString(), Toast.LENGTH_SHORT).show(); } }). setNegativeButton("取消", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { } }). create(); alertDialog.show(); } } public class Dialog_AlertDialogDemoActivity extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); final String[] arrayFruit = new String[] { "苹果", "橘子", "草莓", "香蕉" }; final boolean[] arrayFruitSelected = new boolean[] {true, true, false, false}; Dialog alertDialog = new AlertDialog.Builder(this). setTitle("你喜欢吃哪种水果？"). setIcon(R.drawable.ic_launcher) .setMultiChoiceItems(arrayFruit, arrayFruitSelected, new DialogInterface.OnMultiChoiceClickListener() { @Override public void onClick(DialogInterface dialog, int which, boolean isChecked) { arrayFruitSelected[which] = isChecked; } }). setPositiveButton("确认", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { StringBuilder stringBuilder = new StringBuilder(); for (int i = 0; i < arrayFruitSelected.length; i++) { if (arrayFruitSelected == true) { stringBuilder.append(arrayFruit + "、"); } } Toast.makeText(Dialog_AlertDialogDemoActivity.this, stringBuilder.toString(), Toast.LENGTH_SHORT).show(); } }). setNegativeButton("取消", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { } }). create(); alertDialog.show(); }
}运行结果如下：
六、自定义View的AlertDialog
有时候我们不能满足系统自带的AlertDialog风格，就比如说我们要实现一个Login画面，有用户名和密码，这时我们就要用到自定义View的AlertDialog
先创建Login画面的布局文件
[html]
<?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" > <LinearLayout android:layout_width="fill_parent" android:layout_height="wrap_content" android:gravity="center" > <TextView android:layout_width="0dip" android:layout_height="wrap_content" android:layout_weight="1" android:text="@string/user" /> <EditText android:layout_width="0dip" android:layout_height="wrap_content" android:layout_weight="1" /> </LinearLayout> <LinearLayout android:layout_width="fill_parent" android:layout_height="wrap_content" android:gravity="center" > <TextView android:layout_width="0dip" android:layout_height="wrap_content" android:layout_weight="1" android:text="@string/passward" /> <EditText android:layout_width="0dip" android:layout_height="wrap_content" android:layout_weight="1" /> </LinearLayout> </LinearLayout> <?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" > <LinearLayout android:layout_width="fill_parent" android:layout_height="wrap_content" android:gravity="center" > <TextView android:layout_width="0dip" android:layout_height="wrap_content" android:layout_weight="1" android:text="@string/user" /> <EditText android:layout_width="0dip" android:layout_height="wrap_content" android:layout_weight="1" /> </LinearLayout> <LinearLayout android:layout_width="fill_parent" android:layout_height="wrap_content" android:gravity="center" > <TextView android:layout_width="0dip" android:layout_height="wrap_content" android:layout_weight="1" android:text="@string/passward" /> <EditText android:layout_width="0dip" android:layout_height="wrap_content" android:layout_weight="1" /> </LinearLayout> </LinearLayout>
然后在Activity里面把Login画面的布局文件添加到AlertDialog上
public class Dialog_AlertDialogDemoActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// 取得自定义View
LayoutInflater layoutInflater = LayoutInflater.from(this);
View myLoginView = layoutInflater.inflate(R.layout.login, null);
Dialog alertDialog = new AlertDialog.Builder(this).
setTitle("用户登录").
setIcon(R.drawable.ic_launcher).
setView(myLoginView).
setPositiveButton("登录", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
}
}).
setNegativeButton("取消", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
}
}).
create();
alertDialog.show();
}
}
public class Dialog_AlertDialogDemoActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// 取得自定义View
LayoutInflater layoutInflater = LayoutInflater.from(this);
View myLoginView = layoutInflater.inflate(R.layout.login, null);
Dialog alertDialog = new AlertDialog.Builder(this).
setTitle("用户登录").
setIcon(R.drawable.ic_launcher).
setView(myLoginView).
setPositiveButton("登录", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
}
}).
setNegativeButton("取消", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
}
}).
create();
alertDialog.show();
}
}运行结果如下：
