Android修改Dialog样式的方法

一、Dialog源码解析

1.1 new AlertDialog.Builder(this).create()

    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);
                }
            ..........

• AlertDialog 构造函数中会创建 AlertController，用来控制对话框的布局
• P.apply(dialog.mAlert); 将用户自定义的配置赋值给 AlertController

1.2 AlertController

    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>

二、修改Dialog样式

2.1 通过findViewById

      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。

2.2 自定义style

通过上面源码可以发现，Dialog三个按钮的样式如下：

• buttonBarNeutralButtonStyle
• buttonBarNegativeButtonStyle
• buttonBarPositiveButtonStyle

        <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();

以上就是Android修改Dialog样式的方法的详细内容，更多关于Android修改Dialog样式的资料请关注我们其它相关文章！