Alert Dialog
16lz
2021-01-23
介绍
The AlertDialog class allows you to build a variety of dialog designs and is often the only dialog class you’ll need. there are three regions of an alert dialog:
1.Title
This is optional and should be used only when the content area is occupied by a detailed message, a list, or custom layout. If you need to state a simple message or question (such as the dialog in figure 1), you don’t need a title.2.Content area
This can display a message, a list, or other custom layout.3.Action buttons
There should be no more than three action buttons in a dialog.一般的AlertDialog分为2个部分，头部，内容和Action Button，头部包含图标和文字，内容部分可以自定义，也可以使用一些常见的列表，单选项，多选项等内容，Action Button就是常见的OK啊， Cancel啊等等。
类结构
AlertDialog
重点关注一下Builder类的结构
关于这些方法的使用说明，这里不做一一介绍，后面通过实例可以看出端倪，不过可以通过查阅API文档熟悉一下，AlertDialog.Builder
实际使用
Simple AlertDialog
代码使用
private void showSimpleAlertDialog() { //创建alertdialog builder AlertDialog.Builder builder = new AlertDialog.Builder(mContext); //设置图标，标题，消息内容 builder.setIcon(getResources().getDrawable(R.drawable.ic_adb_black_24dp)) .setTitle(R.string.title) .setMessage(R.string.content); //设置Acton Buttons builder.setNegativeButton(R.string.cancel, new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialogInterface, int i) { Toast.makeText(mContext, "Cancal is clicked", Toast.LENGTH_SHORT).show(); } }); builder.setPositiveButton(R.string.ok, new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialogInterface, int i) { Toast.makeText(mContext, "OK is clicked", Toast.LENGTH_SHORT).show(); } }); builder.setNeutralButton(R.string.reminder, new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialogInterface, int i) { Toast.makeText(mContext, "Remind me later is clicked", Toast.LENGTH_SHORT).show(); } }); //显示alert dialog 这个是AlertDialog的show()方法是等价的 builder.show(); }效果
备注
| Action Button | 意义 |
|---|---|
| setNegativeButton | 做取消、返回等操作，如Cancel |
| setPositiveButton | 做确认、提交等操作，如OK |
| setNeutralButton | 做中性操作，如Update Later |
AlertDialog.Builder中的show()方法和AlertDialog的show()方法是等价的
AlertDialog With Array
代码使用
public void showAlertDialogWithArray() { AlertDialog.Builder builder = new AlertDialog.Builder(mContext); builder.setIcon(getResources().getDrawable(R.drawable.ic_assessment_black_24dp)) .setTitle(R.string.title) .setItems(R.array.dialoglist, new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialogInterface, int i) { switch (i) { case 0: showTwo.setBackgroundResource(R.color.pink); break; case 1: showTwo.setBackgroundResource(R.color.stone); break; case 2: showTwo.setBackgroundResource(R.color.yellow); break; } } }); builder.create().show(); }效果
备注
| 方法 | |
|---|---|
| setItems | 通过array来设置dialog的内容 |
| setAdapter | 通过ListAdapter来设置dialog的内容 |
ListAdapter可以显示的内容应该比Array要丰富，但是现在开源库很多，针对Dialog的美观的开源库也不少，一般开发过程中会使用现成的。
AlertDialog With MultiChoice
代码使用
public void showAlertDialogWithMutiChoice() { final ArrayList<String> selecteditems = new ArrayList<>(); AlertDialog.Builder builder = new AlertDialog.Builder(mContext); builder.setIcon(R.drawable.ic_event_seat_black_24dp) .setTitle(R.string.title) .setMultiChoiceItems(R.array.fruits, null, new DialogInterface.OnMultiChoiceClickListener() { @Override public void onClick(DialogInterface dialogInterface, int which, boolean isChecked) { if (isChecked) { selecteditems.add(getResources() .getStringArray(R.array.fruits)[which]); Toast.makeText(mContext, selecteditems.toString(), Toast.LENGTH_SHORT).show(); } else { selecteditems.remove(getResources() .getStringArray(R.array.fruits)[which]); Toast.makeText(mContext, selecteditems.toString(), Toast.LENGTH_SHORT).show(); } } }); builder.create().show(); }效果
AlertDialog With Single Choice
代码使用
public void showAlertDialogWithSingleChoice() { AlertDialog.Builder builder = new AlertDialog.Builder(mContext); builder.setIcon(R.drawable.ic_build_black_24dp) .setTitle(R.string.title); builder.setSingleChoiceItems(R.array.places, -1, new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialogInterface, int i) { Toast.makeText(mContext, getResources().getStringArray(R.array.places)[i] + " is selected", Toast.LENGTH_SHORT).show(); } }); builder.create().show(); }效果
Custom Alert Dialog
代码使用
public void showCustomAlertDialog() { AlertDialog.Builder builder = new AlertDialog.Builder(mContext); builder.setIcon(R.drawable.ic_assessment_black_24dp).setTitle(R.string.login); builder.setView(R.layout.custom_alert); builder.setCustomTitle(LayoutInflater.from(mContext).inflate(R.layout.custom_title , null )); builder.create().show(); }自定义布局文件
Title自定义
<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="60dp" android:background="@drawable/shape_title" android:orientation="horizontal"> <ImageView android:layout_width="60dp" android:layout_height="60dp" android:paddingLeft="20dp" android:src="@drawable/ic_adb_black_24dp" /> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center_vertical" android:layout_marginLeft="40dp" android:text="Custom Title" android:textSize="15pt" android:textStyle="bold" /></LinearLayout>Content Area自定义
<?xml version="1.0" encoding="utf-8"?><LinearLayout 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:layout_margin="@dimen/activity_horizontal_margin" android:orientation="vertical"> <android.support.design.widget.TextInputLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="10dp"> <EditText android:layout_width="match_parent" android:layout_height="wrap_content" android:hint="UserName" /> </android.support.design.widget.TextInputLayout> <android.support.design.widget.TextInputLayout android:layout_width="match_parent" android:layout_height="wrap_content" app:counterEnabled="true" app:counterMaxLength="40"> <EditText android:layout_width="match_parent" android:layout_height="wrap_content" android:fontFamily="sans-serif" android:hint="Password" android:inputType="textPassword" /> </android.support.design.widget.TextInputLayout> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_margin="@dimen/activity_vertical_margin" android:orientation="horizontal"> <Button android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_weight="1" android:background="@drawable/shaperect" android:text="Submit" /> <Button android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_weight="1" android:background="@drawable/shape_two" android:text="Reset" /> </LinearLayout></LinearLayout>效果
备注
自定义标题栏和显示的内容，Action Button可以通过在Content中添加Button的方式来实现，丰富了Alert Dialog的显示内容，Alert Dialog中应该还有很多东西待挖掘，锄头需要挥起来~
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