我正在EditText上的AlertDialog上添加空字段验证。但即使字段为空，也不会显示错误消息，而是AlertDialog正在关闭。但是如果条件运行良好，因为如果任何一个字段为空，我就无法进行后期操作。
这是我的Java示例代码：
public class TourActivity extends AppCompatActivity {
private LayoutInflater inflater;
private FloatingActionButton fab;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_tour);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
inflater = TourActivity.this.getLayoutInflater();
View content = inflater.inflate(R.layout.activity_add_new_trip, null);
final EditText editEvent = (EditText) content.findViewById(R.id.edTxt_EventName);
final EditText editStartDate = (EditText) content.findViewById(R.id.edTxt_EventSDate);
AlertDialog.Builder builder = new AlertDialog.Builder(TourActivity.this);
builder.setView(content)
.setTitle("Add Event")
.setPositiveButton(android.R.string.ok,
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
editEvent.setError(null);
editStartDate.setError(null);
boolean cancel = false;
View focusView = null;
if (TextUtils.isEmpty(editEvent.getText().toString()))) {
editEvent.setError("Please Enter Event Name.");
return;
}
if (TextUtils.isEmpty(editStartDate.getText().toString())) {
editStartDate.setError("Please Enter Event Start Date.");
focusView = editStartDate;
cancel = true;
}
if (cancel == true) {
Snackbar.make(findViewById(android.R.id.content),
"Event Unsuccessful.", Snackbar.LENGTH_LONG)
.setActionTextColor(Color.RED)
.show();
focusView.requestFocus();
} else {
// Some action here
}
}
})
.setNegativeButton(cancel, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
});
AlertDialog dialog = builder.create();
dialog.show();
}
});
}
}
答案 0 :(得分：4)
此答案来自Android Dialog, keep dialog open when button is pressed。
正如Dismissing Dialog API Guide所述，
当用户触摸使用创建的任何操作按钮时 AlertDialog.Builder，系统为你解开对话框。
因此，您需要创建一个自定义单击侦听器，以防止对话框被关闭。
<强> First Way
您可以阻止正面按钮关闭对话框。你基本上需要：
onClickListener 所以，创建一个监听器类：
class CustomListener implements View.OnClickListener {
private final Dialog dialog;
public CustomListener(Dialog dialog) {
this.dialog = dialog;
}
@Override
public void onClick(View v) {
// Do whatever you want here
// If you want to close the dialog, uncomment the line below
//dialog.dismiss();
}
}
然后在显示对话框时使用：
AlertDialog dialog = dialogBuilder.create();
dialog.show();
Button theButton = dialog.getButton(DialogInterface.BUTTON_POSITIVE);
theButton.setOnClickListener(new CustomListener(dialog));
请记住，您需要显示对话框，否则将无法找到该按钮。此外，请务必将 DialogInterface.BUTTON_POSITIVE 更改为用于添加按钮的任何值。另请注意，在DialogBuilder中添加按钮时，您需要提供onClickListeners - 您无法在其中添加自定义侦听器 - 如果您在之后未覆盖侦听器，则对话框仍会被忽略show()被称为。{/ p>
<强> Second Way
以下是使用匿名类的相同方法的示例，因此它只在一个代码流中：
AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
builder.setMessage("Test for preventing dialog close");
AlertDialog dialog = builder.create();
dialog.show();
//Overriding the handler immediately after show is probably a better approach than OnShowListener as described below
dialog.getButton(AlertDialog.BUTTON_POSITIVE).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
boolean wantToCloseDialog = false;
//Do stuff, possibly set wantToCloseDialog to true then...
if(wantToCloseDialog)
dismiss();
//else dialog stays open. Make sure you have an obvious way to close the dialog especially if you set cancellable to false.
}
});
答案 1 :(得分：0)
这是在AlertDialog中验证输入密码的方法。
请确保您为密码创建了一个单独的xml布局文件，该文件只有一个组件/视图为EditText，可以从用户那里获取密码。
为输入密码创建布局后，我们将使用Dialog扩展该布局，以将自定义视图设置为AlertDialog。
Inflater inflater = new Inflater(this);
View myPasswordView = inflater.inflate(R.xml.my_custom_password_layout);
AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(this);
alertDialogBuilder.setTitle("Password");
//alertDialogBuilder.setMessage("Enter password to open Application.");
alertDialogBuilder.setView(myPasswordView);
alertDialogBuilder.setPositiveButton("Ok", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which)
{
// Do not use this place as we are overriding this button later in the cade.
}
}); alertDialogBuilder.setPositiveButton("Cancel",
new DialogInterface.OnClickListener({
@Override
public void onClick(DialogInterface dialog, int which)
{
// Dismiss dialog and close activity if appropriated, do not use this (cancel) button at all.
dialog.dismiss();
}
});
final AlertDialog alertDialog = alertDialogBuilder.create();
alertDialog.show();
// Overriding the that button here immediatly handle the user's activity.
alertDialog.getButton(AlertDialog.BUTTON_POSITIVE).setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v)
{
Boolean isError = false;
//Do your job here. For example we are checking the input password.
final EditText txtPassword = myPasswordView.findViewById(R.id.txtPassword);
String password = txtPassword.getText().toString().trim();
Boolean isError = true;
// Check password if not empty. You can add another IF statement to do your logic for password validation.
if(password.isEmpty()) {
isError = true;
txtPassword.setError("Password cannot be empty");
}
if(password.equals("1234") {
// You password is correct.
isError = false;
txtPassword.setError(null);
}
if(!isError)
dialog.dismiss();
// Otherwise the dialog will stay open.
}
});
答案 2 :(得分：-1)
试试这样：
if (TextUtils.isEmpty(edEvent)) {
editEvent.setError("Please Enter Event Name.");
editEvent.requestFocus();
return;
}