Android Getting Started Tutorial | Use of DialogFragment

Pop-up windows are a common way of prompting.

DialogFragment was introduced in 3.0. It is a special Fragment used to display a modal dialog box on Activity.

DialogFragment example

Determine UI style

First we have to know what to make. Generally speaking, a simple pop-up window has a title and text content at one end. Or with a button or two.

Here we make a simple pop-up window with a title and text.

layout

After determining the style, write the layout first.

dialog_simple.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="12dp">

    <TextView
        android:id="@+id/title_tv"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:textColor="#111111"
        android:textSize="16sp"
        android:textStyle="bold"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:id="@+id/content_tv"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:gravity="center"
        android:textColor="#111111"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@id/title_tv" />

</androidx.constraintlayout.widget.ConstraintLayout>

Create a new pop-up window class

Create a new SimpleDialogclass inheritance DialogFragment.

existonCreate方法中接收传入的数据。传递数据使用了Bundle。import android.os.Bundle; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.TextView; import androidx.annotation.NonNull; import androidx.annotation.Nullable; import androidx.fragment.app.DialogFragment; public class SimpleDialog extends DialogFragment { public static final String K_TITLE = “k_title”; // 传输数据时用到的key public static final String K_CONTENT = “k_content”; private String title; private String content; @Override public void onCreate(@Nullable Bundle savedInstanceState) { super.onCreate(savedInstanceState); Bundle in = getArguments(); if (in != null) { title = in.getString(K_TITLE); content = in.getString(K_CONTENT); } } @Nullable @Override public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) { return inflater.inflate(R.layout.dialog_simple, container, false); } @Override public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) { super.onViewCreated(view, savedInstanceState); TextView titleTv = view.findViewById(R.id.title_tv); TextView contentTv = view.findViewById(R.id.content_tv); titleTv.setText(title); contentTv.setText(content); } }
In onCreateViewthe method, use the layout created above.
onViewCreatedPerform ui operations in methods .

use

Pop this window up. We use DialogFragment.show(@NonNull FragmentManager manager, @Nullable String tag)methods.

private void popSimpleDialog1(String title, String content) {
    
    
        SimpleDialog dialog = new SimpleDialog();
        Bundle bundle = new Bundle();
        bundle.putString(SimpleDialog.K_TITLE, title);
        bundle.putString(SimpleDialog.K_CONTENT, content);
        dialog.setArguments(bundle);
        dialog.show(getSupportFragmentManager(), "one-tag");
    }

    // 调用
    popSimpleDialog1("欢迎访问");

Run it on the machine and you can see the effect.

Summary :

Use DialogFragment to implement pop-up windows. You need to determine the ui style, create a layout, create a new class that inherits DialogFragment, and pass in data.

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