android alertdialog适配不同屏幕的方法

要使Android AlertDialog适应不同屏幕，可以采用以下方法：

1. 使用dp单位定义AlertDialog的尺寸和边距，以确保在不同屏幕密度上具有一致的外观。例如：

int dialogWidthInDp = 300;
int dialogHeightInDp = 200;
int dialogMarginInDp = 16;

Resources resources = getResources();
float scale = resources.getDisplayMetrics().density;
int dialogWidthInPixels = (int) (dialogWidthInDp * scale + 0.5f);
int dialogHeightInPixels = (int) (dialogHeightInDp * scale + 0.5f);
int dialogMarginInPixels = (int) (dialogMarginInDp * scale + 0.5f);

AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setView(view);
builder.setCancelable(true);

AlertDialog alertDialog = builder.create();
alertDialog.getWindow().setLayout(dialogWidthInPixels, dialogHeightInPixels);
alertDialog.getWindow().setMargins(dialogMarginInPixels, dialogMarginInPixels, dialogMarginInPixels, dialogMarginInPixels);

2. 使用Theme和Style来定义AlertDialog的外观，以便在不同屏幕密度上保持一致性。例如，可以在res/values/styles.xml中定义一个自定义样式：

<resources>
    <style name="CustomAlertDialogStyle" parent="Theme.AppCompat.Light.Dialog.Alert">
        <item name="colorAccent">@color/colorAccent</item>
        <item name="alertDialogTheme">@style/CustomAlertDialogTheme</item>
    </style>

    <style name="CustomAlertDialogTheme" parent="ThemeOverlay.AppCompat.Dialog.Alert">
        <item name="buttonBarNegativeButtonStyle">@style/NegativeButtonStyle</item>
        <item name="buttonBarPositiveButtonStyle">@style/PositiveButtonStyle</item>
        <item name="buttonBarNeutralButtonStyle">@style/NeutralButtonStyle</item>
    </style>

    <style name="NegativeButtonStyle" parent="Widget.AppCompat.Button.ButtonBar.AlertDialog">
        <item name="android:textColor">@color/negativeButtonText</item>
    </style>

    <style name="PositiveButtonStyle" parent="Widget.AppCompat.Button.ButtonBar.AlertDialog">
        <item name="android:textColor">@color/positiveButtonText</item>
    </style>

    <style name="NeutralButtonStyle" parent="Widget.AppCompat.Button.ButtonBar.AlertDialog">
        <item name="android:textColor">@color/neutralButtonText</item>
    </style>
</resources>

然后在创建AlertDialog.Builder时应用此样式：

AlertDialog.Builder builder = new AlertDialog.Builder(this, R.style.CustomAlertDialogStyle);

通过以上方法，可以确保AlertDialog在不同屏幕尺寸和密度上具有一致的外观和良好的用户体验。