一个按钮
import android.support.v7.app.AlertDialog;
public class MainActivity extends AppCompatActivity {
public void showAlertDialogButtonClicked(View view) {
// setup the alert builder
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("My title");
builder.setMessage("This is my message.");
// add a button
builder.setPositiveButton("OK", null);
// create and show the alert dialog
AlertDialog dialog = builder.create();
dialog.show();
}
}
两个按钮
public class MainActivity extends AppCompatActivity {
public void showAlertDialogButtonClicked(View view) {
// setup the alert builder
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("AlertDialog");
builder.setMessage("Would you like to continue learning how to use Android alerts?");
// add the buttons
builder.setPositiveButton("Continue", null);
builder.setNegativeButton("Cancel", null);
// create and show the alert dialog
AlertDialog dialog = builder.create();
dialog.show();
}
}
三个按钮
public class MainActivity extends AppCompatActivity {
public void showAlertDialogButtonClicked(View view) {
// setup the alert builder
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("Notice");
builder.setMessage("Launching this missile will destroy the entire universe. Is this what you intended to do?");
// add the buttons
builder.setPositiveButton("Launch missile", null);
builder.setNeutralButton("Remind me later", null);
builder.setNegativeButton("Cancel", null);
// create and show the alert dialog
AlertDialog dialog = builder.create();
dialog.show();
}
}
如果按钮文本太长而无法水平放置,那么它将自动排列在三个按钮的垂直列中。
处理按钮点击
在上述示例中,OnClickListener 是 null。您可以将null 替换为侦听器以在用户点击按钮时执行某些操作。例如:
builder.setPositiveButton("Launch missile", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
// do something like...
launchMissile();
}
});
继续
您可以制作更多种类的对话框。请参阅documentation 获取相关帮助。
由于AlertDialog 中仅支持三个按钮,因此这里是一个带有列表的对话框示例。
public class MainActivity extends AppCompatActivity {
public void showAlertDialogButtonClicked(View view) {
// setup the alert builder
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("Choose an animal");
// add a list
String[] animals = {"horse", "cow", "camel", "sheep", "goat"};
builder.setItems(animals, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
switch (which) {
case 0: // horse
case 1: // cow
case 2: // camel
case 3: // sheep
case 4: // goat
}
}
});
// create and show the alert dialog
AlertDialog dialog = builder.create();
dialog.show();
}
}
有关单选按钮列表和复选框列表的类似示例,请参阅this answer。
注意事项
- 使用字符串资源而不是硬编码字符串。
- 您可以将所有内容包装在一个扩展
DialogFragment 的类中,以便轻松重用对话框。 (请参阅this 寻求帮助。)
-
这些示例使用支持库来支持 API 11 之前的版本。所以导入应该是
import android.support.v7.app.AlertDialog;
为简洁起见,我在上面的示例中省略了 onCreate 方法。那里没有什么特别的。
另见