Question

我尝试使用自定义布局创建AlertDialog。当我尝试从内部按钮关闭对话框时出现问题，所以我之前将其声明为final。虽然正确引用了元素id，但它会抛出一个错误，说自定义的layoutelement为null。这是代码：

Context ctx = MyActivity.this;
AlertDialog.Builder builder = new AlertDialog.Builder(ctx);
LayoutInflater inflater = (LayoutInflater) ctx.getSystemService( ctx.LAYOUT_INFLATER_SERVICE );
View dialogView = inflater.inflate(R.layout.mkdialog_layout, null);
builder.setView(dialogView);
final AlertDialog myalertdialog = builder.create();
Button okbtt = (Button)myalertdialog.findViewById(R.id.mkdialog_okbtt);
Button cancelbtt = (Button)myalertdialog.findViewById(R.id.mkdialog_cancelbtt);
TextView title = (TextView)myalertdialog.findViewById(R.id.mkdialog_titletv);
title.setText("Are you sure you want to log out?");
okbtt.setOnClickListener(new View.OnClickListener(){
  public void onClick(View id) {
                        myalertdialog.dismiss();                        
                        Intent i = new Intent(getBaseContext(), LoginActivity.class);
                        i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
                        startActivity(i);
                        finish();
                }});
cancelbtt.setOnClickListener(new View.OnClickListener(){
                    public void onClick(View id) {
                        myalertdialog.dismiss();
                    }});
myalertdialog.show();

错误：

Process: com.mk.companionapp, PID: 22045 java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference
    at com.mk.companionapp.activities.ConfigurationActivity$2.onClick(ConfigurationActivity.java:185)
        at android.view.View.performClick(View.java:5204)
        at android.view.View$PerformClick.run(View.java:21153)
        at android.os.Handler.handleCallback(Handler.java:739)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:148)
        at android.app.ActivityThread.main(ActivityThread.java:5417)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

提前致谢

Answer 1

用此更新对话框代码。

Context ctx = getApplicationContext();
AlertDialog.Builder builder = new AlertDialog.Builder(ctx);
LayoutInflater inflater = (LayoutInflater) ctx.getSystemService( ctx.LAYOUT_INFLATER_SERVICE );
View dialogView = inflater.inflate(R.layout.mkdialog_layout, null);
builder.setView(dialogView);
final AlertDialog myalertdialog = builder.create();
Button okbtt = (Button)dialogView.findViewById(R.id.mkdialog_okbtt);
Button cancelbtt = (Button)dialogView.findViewById(R.id.mkdialog_cancelbtt);
TextView title = (TextView)dialogView.findViewById(R.id.mkdialog_titletv);
title.setText("Are you sure you want to log out?");
okbtt.setOnClickListener(new View.OnClickListener(){
  public void onClick(View id) {
                        myalertdialog.dismiss();                        
                        Intent i = new Intent(getBaseContext(), LoginActivity.class);
                        i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
                        startActivity(i);
                        finish();
                }});
cancelbtt.setOnClickListener(new View.OnClickListener(){
                    public void onClick(View id) {
                        myalertdialog.dismiss();
                    }});
myalertdialog.show();

您使用错误的视图初始化了view_items。

Answer 2

而不是myalertdialog，您应该使用dialogView。因此，要使代码正常工作，您必须替换

TextView title = (TextView)myalertdialog.findViewById(R.id.mkdialog_titletv);

以下

TextView title = (TextView) dialogView.findViewById(R.id.mkdialog_titletv);

Answer 3

正如其他人所说，使用dialogView来查找视图而不是myalertdialog，并且将活动上下文传递给Dialog而不是应用程序上下文。因此，请进行以下更改。

上下文ctx = YourActivity.this;

TextView title =（TextView）myalertdialog.findViewById（R.id.mkdialog_titletv）;

到

TextView title =（TextView）dialogView.findViewById（R.id.mkdialog_titletv）;

Answer 4

使用它。您必须使用Activity来创建AlertDialog。不要使用ApplicationContext

AlertDialog.Builder builder = new AlertDialog.Builder(this);

Answer 5

TextView title = (TextView)myalertdialog.findViewById(R.id.mkdialog_titletv);

到

TextView title = (TextView) dialogView.findViewById(R.id.mkdialog_titletv);

Answer 6

使用以下方法将阻止Alert在我们单击任何按钮后立即关闭，并根据我们的业务逻辑提供关闭选项。

以下示例提醒在EditText

中有文字和custom_dialog

        final AlertDialog.Builder dialog = new AlertDialog.Builder(this);
        LayoutInflater inflater = this.getLayoutInflater();
        final View dialogView = inflater.inflate(R.layout.custom_dialog, null);
        dialog.setView(dialogView);
        final EditText edt = (EditText)dialogView.findViewById(R.id.email_forgot);
        dialog.setView(dialogView);
        dialog.setPositiveButton("Ok",new DialogInterface.OnClickListener()
        {
            @Override
            public void onClick(DialogInterface dialog, int which)
            {
            }
        });
        dialog.setNegativeButton("Cancel",new DialogInterface.OnClickListener()
        {
            @Override
            public void onClick(DialogInterface dialog, int which)
            {
                dialog.dismiss();
            }
        });
        AlertDialog forgotAlertDialog = dialog.create();
        forgotAlertDialog.show();
        forgotAlertDialog.getButton(AlertDialog.BUTTON_POSITIVE).setOnClickListener(new View.OnClickListener()
        {
            @Override
            public void onClick(View v)
            {
                //your positive action
            }
        });

要关闭警报，请按照逻辑

执行以下操作

if (forgotAlertDialog.isShowing()) {
     forgotAlertDialog.dismiss();
}

AlertDialog的自定义布局问题

6 个答案: