Question

pbutton.setOnClickListener(new OnClickListener()
    {   private AlertDialog show;
        public void onClick(View arg0)
        {   
            if ((input1.getText().length() == 0) || (input1.getText().toString().equals(" ")) || (input2.getText().length() == 0) || (input2.getText().toString().equals(" "))|| (input1.getText().toString().equals(""))||(input2.getText().toString().equals("")))
            {

            show = new AlertDialog.Builder(MainActivity.this).setTitle("Error").setMessage("Some inputs are empty").setPositiveButton("OK", null).show();
            }
            double result = new Double(input1.getText().toString())+ new Double(input2.getText().toString());
            output.setText(Double.toString(result));

        }

我也试过传递也不起作用的上下文

Answer 1

以这种方式使用： -

   b.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
              if ((input1.getText().length() == 0) || (input1.getText().toString().equals(" ")) || (input2.getText().length() == 0) || (input2.getText().toString().equals(" "))|| (input1.getText().toString().equals(""))||(input2.getText().toString().equals("")))
                {
            showAlert();
                }
        }
    });
}
private void showAlert() {
    AlertDialog.Builder alertbox = new AlertDialog.Builder(this);
            alertbox.setMessage("Some Inputs are Empty");
            alertbox.setTitle("error"); 
    alertbox.setNeutralButton("Ok", new DialogInterface.OnClickListener() {
       public void onClick(DialogInterface arg0, int arg1) {

        }
    });

     alertbox.show();

  }

Answer 2

我认为你需要先调用create()，如：

show = new AlertDialog.Builder(MainActivity.this).setTitle("Error").setMessage("Some inputs are empty").setPositiveButton("OK", null).create();

show.show();

修改：

AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(context); alertDialogBuilder.setTitle("Error"); alertDialogBuilder.setMessage("Some inputs are empty"); alertDialogBuilder.setPositiveButton("Yes",new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog,int id) { // if this button is clicked, .... } }); AlertDialog alertDialog = alertDialogBuilder.create(); alertDialog.show();

Answer 3

我按原样使用了您的代码并且工作正常。请确保您不是导入

导入android.content.DialogInterface.OnClickListener;

如果您导入上面的侦听器，那么它将无效你必须在下面导入，

导入android.view.View.OnClickListener;

然后肯定会有效。

我的对话框不起作用，请更正

3 个答案: