David Hedlund发布的代码给了我错误:

无法添加窗口-空令牌无效

如果你得到同样的错误，请使用下面的代码。它的工作原理!

runOnUiThread(new Runnable() {
    @Override
    public void run() {

        if (!isFinishing()){
            new AlertDialog.Builder(YourActivity.this)
              .setTitle("Your Alert")
              .setMessage("Your Message")
              .setCancelable(false)
              .setPositiveButton("ok", new OnClickListener() {
                  @Override
                  public void onClick(DialogInterface dialog, int which) {
                      // Whatever...
                  }
              }).show();
        }
    }
});

使用AlertDialog。建造者:

AlertDialog alertDialog = new AlertDialog.Builder(this)
//set icon 
 .setIcon(android.R.drawable.ic_dialog_alert)
//set title
.setTitle("Are you sure to Exit")
//set message
.setMessage("Exiting will call finish() method")
//set positive button
.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
    @Override
    public void onClick(DialogInterface dialogInterface, int i) {
   //set what would happen when positive button is clicked    
        finish();
    }
})
//set negative button
.setNegativeButton("No", new DialogInterface.OnClickListener() {
    @Override
    public void onClick(DialogInterface dialogInterface, int i) {
   //set what should happen when negative button is clicked
        Toast.makeText(getApplicationContext(),"Nothing Happened",Toast.LENGTH_LONG).show();
    }
})
.show();

您将得到以下输出。

要查看警报对话框教程使用下面的链接。

Android警报对话框教程

David Hedlund发布的代码给了我错误:

无法添加窗口-空令牌无效

如果你得到同样的错误，请使用下面的代码。它的工作原理!

runOnUiThread(new Runnable() {
    @Override
    public void run() {

        if (!isFinishing()){
            new AlertDialog.Builder(YourActivity.this)
              .setTitle("Your Alert")
              .setMessage("Your Message")
              .setCancelable(false)
              .setPositiveButton("ok", new OnClickListener() {
                  @Override
                  public void onClick(DialogInterface dialog, int which) {
                      // Whatever...
                  }
              }).show();
        }
    }
});

你可以创建Activity并扩展AppCompatActivity。然后在清单中加入下一种风格

<activity android:name=".YourCustomDialog"
            android:theme="Theme.AppCompat.Light.Dialog">
</activity>

充气它的按钮和TextViews

然后把这个当做一个对话。

例如，在linearLayout中，我填充下一个参数:

android:layout_width="300dp"
android:layout_height="wrap_content"

带有编辑文本的警报对话框

AlertDialog.Builder builder = new AlertDialog.Builder(context);//Context is activity context
final EditText input = new EditText(context);
builder.setTitle(getString(R.string.remove_item_dialog_title));
        builder.setMessage(getString(R.string.dialog_message_remove_item));
 builder.setTitle(getString(R.string.update_qty));
            builder.setMessage("");
            LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(
                    LinearLayout.LayoutParams.MATCH_PARENT,
                    LinearLayout.LayoutParams.MATCH_PARENT);
            input.setLayoutParams(lp);
            input.setHint(getString(R.string.enter_qty));
            input.setTextColor(ContextCompat.getColor(context, R.color.textColor));
            input.setInputType(InputType.TYPE_CLASS_NUMBER);
            input.setText("String in edit text you want");
            builder.setView(input);
   builder.setPositiveButton(getString(android.R.string.ok),
                (dialog, which) -> {

//Positive button click event
  });

 builder.setNegativeButton(getString(android.R.string.cancel),
                (dialog, which) -> {
//Negative button click event
                });
        AlertDialog dialog = builder.create();
        dialog.show();

在过去的几天里，我的同事一直在问我如何在Xamarin中使用AlertDialog。Android和几乎所有人都把这个问题作为参考发给了我，他们在问我之前读了这个问题(没有找到答案)，所以这里是Xamarin。Android (c#)版本:

var alertDialog = new AlertDialog.Builder(this) // this: Activity
    .SetTitle("Hello!")
    .SetMessage("Are you sure?")
    .SetPositiveButton("Ok", (sender, e) => { /* ok things */ })
    .SetNegativeButton("Cancel", (sender, e) => { /* cancel things */ })
    .Create();

alertDialog.Show();

// you can customize your AlertDialog, like so
var tvMessage = alertDialog.FindViewById<TextView>(Android.Resource.Id.Message);
tvMessage.TextSize = 13;
// ...