protected AlertDialog(@NonNull Context context, @StyleRes int themeResId) {
super(context, resolveDialogTheme(context, themeResId));
//创建AlertController，是Dialog布局相关代码
mAlert = new AlertController(getContext(), this, getWindow());
}
@NonNull
public AlertDialog create() {
// We can't use Dialog's 3-arg constructor with the createThemeContextWrapper param,
// so we always have to re-set the theme
final AlertDialog dialog = new AlertDialog(P.mContext, mTheme);
P.apply(dialog.mAlert);
dialog.setCancelable(P.mCancelable);
if (P.mCancelable) {
dialog.setCanceledOnTouchOutside(true);
}
dialog.setOnCancelListener(P.mOnCancelListener);
dialog.setOnDismissListener(P.mOnDismissListener);
if (P.mOnKeyListener != null) {
dialog.setOnKeyListener(P.mOnKeyListener);
}
return dialog;
}
public void apply(AlertController dialog) {
if (mCustomTitleView != null) {
dialog.setCustomTitle(mCustomTitleView);
} else {
if (mTitle != null) {
dialog.setTitle(mTitle);
}
if (mIcon != null) {
dialog.setIcon(mIcon);
}
if (mIconId != 0) {
dialog.setIcon(mIconId);
}
..........
public AlertController(Context context, AppCompatDialog di, Window window) {
mContext = context;
mDialog = di;
mWindow = window;
mHandler = new ButtonHandler(di);
final TypedArray a = context.obtainStyledAttributes(null, R.styleable.AlertDialog,
R.attr.alertDialogStyle, 0);
mAlertDialogLayout = a.getResourceId(R.styleable.AlertDialog_android_layout, 0);
mButtonPanelSideLayout = a.getResourceId(R.styleable.AlertDialog_buttonPanelSideLayout, 0);
mListLayout = a.getResourceId(R.styleable.AlertDialog_listLayout, 0);
mMultiChoiceItemLayout = a.getResourceId(R.styleable.AlertDialog_multiChoiceItemLayout, 0);
mSingleChoiceItemLayout = a
.getResourceId(R.styleable.AlertDialog_singleChoiceItemLayout, 0);
mListItemLayout = a.getResourceId(R.styleable.AlertDialog_listItemLayout, 0);
mShowTitle = a.getBoolean(R.styleable.AlertDialog_showTitle, true);
mButtonIconDimen = a.getDimensionPixelSize(R.styleable.AlertDialog_buttonIconDimen, 0);
a.recycle();
/* We use a custom title so never request a window title */
di.supportRequestWindowFeature(Window.FEATURE_NO_TITLE);
}
R.attr.alertDialogStyle 是 对话框的默认样式，
<item name="alertDialogStyle">@style/AlertDialog.AppCompat</item>
<style name="AlertDialog.AppCompat" parent="Base.AlertDialog.AppCompat"/>
<style name="Base.AlertDialog.AppCompat" parent="android:Widget">
<item name="android:layout">@layout/abc_alert_dialog_material</item>
<item name="listLayout">@layout/abc_select_dialog_material</item>
<item name="listItemLayout">@layout/select_dialog_item_material</item>
<item name="multiChoiceItemLayout">@layout/select_dialog_multichoice_material</item>
<item name="singleChoiceItemLayout">@layout/select_dialog_singlechoice_material</item>
<item name="buttonIconDimen">@dimen/abc_alert_dialog_button_dimen</item>
</style>
上述代码可以看出，abc_alert_dialog_material 就是dialog的默认布局。
<androidx.appcompat.widget.AlertDialogLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/parentPanel"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="start|left|top"
android:orientation="vertical">
<include layout="@layout/abc_alert_dialog_title_material"/>
<FrameLayout
android:id="@+id/contentPanel"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:minHeight="48dp">
<View android:id="@+id/scrollIndicatorUp"
android:layout_width="match_parent"
android:layout_height="1dp"
android:layout_gravity="top"
android:background="?attr/colorControlHighlight"
android:visibility="gone"/>
<androidx.core.widget.NestedScrollView
android:id="@+id/scrollView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:clipToPadding="false">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<android.widget.Space
android:id="@+id/textSpacerNoTitle"
android:layout_width="match_parent"
android:layout_height="@dimen/abc_dialog_padding_top_material"
android:visibility="gone"/>
<TextView
android:id="@android:id/message"
style="@style/TextAppearance.AppCompat.Subhead"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingLeft="?attr/dialogPreferredPadding"
android:paddingRight="?attr/dialogPreferredPadding"/>
<android.widget.Space
android:id="@+id/textSpacerNoButtons"
android:layout_width="match_parent"
android:layout_height="@dimen/abc_dialog_padding_top_material"
android:visibility="gone"/>
</LinearLayout>
</androidx.core.widget.NestedScrollView>
<View android:id="@+id/scrollIndicatorDown"
android:layout_width="match_parent"
android:layout_height="1dp"
android:layout_gravity="bottom"
android:background="?attr/colorControlHighlight"
android:visibility="gone"/>
</FrameLayout>
<FrameLayout
android:id="@+id/customPanel"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:minHeight="48dp">
<FrameLayout
android:id="@+id/custom"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
</FrameLayout>
<include layout="@layout/abc_alert_dialog_button_bar_material"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
</androidx.appcompat.widget.AlertDialogLayout>
标题布局：
<!-- abc_alert_dialog_title_material: -->
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/topPanel"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<!-- If the client uses a customTitle, it will be added here. -->
<LinearLayout
android:id="@+id/title_template"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center_vertical|start|left"
android:orientation="horizontal"
android:paddingLeft="?attr/dialogPreferredPadding"
android:paddingRight="?attr/dialogPreferredPadding"
android:paddingTop="@dimen/abc_dialog_padding_top_material">
<ImageView
android:id="@android:id/icon"
android:layout_width="32dip"
android:layout_height="32dip"
android:layout_marginEnd="8dip"
android:layout_marginRight="8dip"
android:scaleType="fitCenter"
android:src="@null"/>
<androidx.appcompat.widget.DialogTitle
android:id="@+id/alertTitle"
style="?android:attr/windowTitleStyle"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="start"
android:ellipsize="end"
android:singleLine="true"
android:textAlignment="viewStart"/>
</LinearLayout>
<android.widget.Space
android:id="@+id/titleDividerNoCustom"
android:layout_width="match_parent"
android:layout_height="@dimen/abc_dialog_title_divider_material"
android:visibility="gone"/>
</LinearLayout>
按钮布局：
<!-- abc_alert_dialog_button_bar_material: -->
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/buttonPanel"
style="?attr/buttonBarStyle"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:fillViewport="true"
android:scrollIndicators="top|bottom">
<androidx.appcompat.widget.ButtonBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="bottom"
android:layoutDirection="locale"
android:orientation="horizontal"
android:paddingBottom="4dp"
android:paddingLeft="12dp"
android:paddingRight="12dp"
android:paddingTop="4dp">
<Button
android:id="@android:id/button3"
style="?attr/buttonBarNeutralButtonStyle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
<android.widget.Space
android:id="@+id/spacer"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_weight="1"
android:visibility="invisible"/>
<Button
android:id="@android:id/button2"
style="?attr/buttonBarNegativeButtonStyle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
<Button
android:id="@android:id/button1"
style="?attr/buttonBarPositiveButtonStyle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
</androidx.appcompat.widget.ButtonBarLayout>
</ScrollView>
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setMessage(msg);
builder.setPositiveButton(getString(R.string.yes), null);
AlertDialog dialog = builder.create();
dialog.show();
//直接通过id找到对应的控件
Button button = dialog.findViewById(android.R.id.button1);
//或者通过getButton方法也可以获取到
Button button2 = dialog.getButton(DialogInterface.BUTTON_POSITIVE);
这种修改方式必须在 show() 之后调用，否则会出现空指针异常。这个是因为，执行 show() 方法的时候，dialog才会初始化布局，具体源码可以查看 Dialog 的 onCreate 方法。
通过上面源码可以发现，Dialog三个按钮的样式如下：
<Button
android:id="@android:id/button3"
style="?attr/buttonBarNeutralButtonStyle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
<android.widget.Space
android:id="@+id/spacer"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_weight="1"
android:visibility="invisible"/>
<Button
android:id="@android:id/button2"
style="?attr/buttonBarNegativeButtonStyle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
<Button
android:id="@android:id/button1"
style="?attr/buttonBarPositiveButtonStyle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
自定义样式替换上述 style即可达到修改效果。
在style.xml添加如下代码：
<style name="accessPositiveBtnStyle" parent="Widget.AppCompat.Button.ButtonBar.AlertDialog">
<item name="android:textColor">@color/test1</item>
</style>
<style name="accessNegativeBtnStyle" parent="Widget.AppCompat.Button.ButtonBar.AlertDialog">
<item name="android:textColor">@color/test2</item>
</style>
<!-- 弹出框样式 -->
<style name="testDialogTheme" parent="Theme.AppCompat.Light.Dialog.Alert">
<item name="buttonBarPositiveButtonStyle">@style/accessPositiveBtnStyle</item>
<item name="buttonBarNegativeButtonStyle">@style/accessNegativeBtnStyle</item>
</style>
具体使用：
AlertDialog.Builder builder = new AlertDialog.Builder(this, R.style.testDialogTheme);
builder.setMessage("Test");
builder.setCancelable(false);
builder.setPositiveButton("确认", null);
builder.setNegativeButton("取消", null);
Dialog dialog = builder.create();
dialog.show();
