Android dialog使用

翻译自：开发->API 指南->User Interface & Navigation->Dialogs

注意：

dialog是一个基类，但是我们应该尽可能避免直接使用dialog，而是应该使用其子类，比如AlertDialog，DatePickerDialog或者TimePickerDialog等。

使用DialogFragment去管理dialog，这会让你的app在用户点击返回键和旋转屏幕时，正确的控制dialog的生命周期。DialogFragment与传统的Fragment基本一致。

Creating a Dialog Fragment

使用DialogFragment创建一个基本的AlertDialog

public class FireMissilesDialogFragment extends DialogFragment {
    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        // Use the Builder class for convenient dialog construction
        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
        builder.setMessage(R.string.dialog_fire_missiles)
               .setPositiveButton(R.string.fire, new DialogInterface.OnClickListener() {
                   public void onClick(DialogInterface dialog, int id) {
                       // FIRE ZE MISSILES!
                   }
               })
               .setNegativeButton(R.string.cancel, new DialogInterface.OnClickListener() {
                   public void onClick(DialogInterface dialog, int id) {
                       // User cancelled the dialog
                   }
               });
        // Create the AlertDialog object and return it
        return builder.create();
    }
}

如果你创建了以上的dialog，并且调用了show()方法，那你会看到如下所示的dialog。

Building an Alert Dialog

Alert Dialog包括三部分，标题，内容和按钮，如下图所示

创建一个Alert Dialog

// 1. Instantiate an AlertDialog.Builder with its constructor
AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());

// 2. Chain together various setter methods to set the dialog characteristics
builder.setMessage(R.string.dialog_message)
       .setTitle(R.string.dialog_title);

// 3. Get the AlertDialog from create()
AlertDialog dialog = builder.create();

添加按钮

AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
// Add the buttons
builder.setPositiveButton(R.string.ok, new DialogInterface.OnClickListener() {
           public void onClick(DialogInterface dialog, int id) {
               // User clicked OK button
           }
       });
builder.setNegativeButton(R.string.cancel, new DialogInterface.OnClickListener() {
           public void onClick(DialogInterface dialog, int id) {
               // User cancelled the dialog
           }
       });
// Set other dialog properties
...

// Create the AlertDialog
AlertDialog dialog = builder.create();

dialog里也可以添加list，具体的可以查看官方文档。

Creating a Custom Layout

If you want a custom layout in a dialog, create a layout and add it to an AlertDialog by calling setView() on your AlertDialog.Builder object.

如果想使用自定义布局，可以在AlertDialog.Builder中调用setView()方法，将自定义布局添加到AlertDialog中。

@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
    AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
    // Get the layout inflater
    LayoutInflater inflater = getActivity().getLayoutInflater();

    // Inflate and set the layout for the dialog
    // Pass null as the parent view because its going in the dialog layout
    builder.setView(inflater.inflate(R.layout.dialog_signin, null))
    // Add action buttons
           .setPositiveButton(R.string.signin, new DialogInterface.OnClickListener() {
               @Override
               public void onClick(DialogInterface dialog, int id) {
                   // sign in the user ...
               }
           })
           .setNegativeButton(R.string.cancel, new DialogInterface.OnClickListener() {
               public void onClick(DialogInterface dialog, int id) {
                   LoginDialogFragment.this.getDialog().cancel();
               }
           });
    return builder.create();
}

小提示：如果你想创建一个自定义dialog，你可以显示一个Activity去代替dialog，只需要在

<activity android:theme="@android:style/Theme.Holo.Dialog" >

搞定，这样activity就会显示成 一个dialog，而不是全屏显示啦。