Android中Dialog系统样式讲解

     今天在维护公司的一个APP的时候,有如下场景。

弹出一个AlertDialog的时候，在系统语言是中文的时候，如下所示：

弹出一个AlertDialog的时候，在系统语言是English的时候，如下所示：

 

可以发现在系统语言为英语的时候，对话框中的白色文字已经完全看不清楚，对话框的背景颜色也变成了白色。因此需要修改对话框的主题。

 

修改之前代码如下：

 AlertDialog commedialog = new AlertDialog.Builder(
                     WalkieTalkieActivity.this)
                     .setTitle(title)
                     .setView(vi_nolong)
                     .setPositiveButton(
                             WalkieTalkieActivity.this.getResources().getString(R.string.ok),
                             new DialogInterface.OnClickListener() {
                                 public void onClick(DialogInterface dialog, int arg1) {

                                     int j = mSelectedGroupNum + 1;
                                     int power_last = mIntercomSharePrefs.getInt("CurrentPower_"+j,0);
                                     Log.i("wxj", "btn_power CurrentPower_"+j+" :" + power_last);
                                     if (power_last == 1) {
                                         mEditor.putInt("CurrentPower_"+j,0).commit();
                                         mIntercom.setPowerLevel(0);
                                         btn_power.setBackgroundResource(R.drawable.power_high);

                                     } else if (power_last == 0) {
                                         mEditor.putInt("CurrentPower_"+j,1).commit();
                                         mIntercom.setPowerLevel(1);
                                         btn_power.setBackgroundResource(R.drawable.power_low);
                                     }
                                     dialog.dismiss();
                                     ((ViewGroup) vi_nolong.getParent()).removeView(vi_nolong);
                                 }
                             })
                     .setNegativeButton(
                             WalkieTalkieActivity.this.getResources().getString(R.string.cancel),
                             new DialogInterface.OnClickListener() {
                                 public void onClick(DialogInterface dialog,
                                         int whichButton) {

                                     dialog.dismiss();
                                     ((ViewGroup) vi_nolong.getParent()).removeView(vi_nolong);
                                 }
                             }).create();
             commedialog.setCanceledOnTouchOutside(false);
             commedialog.show();

 

可以发现，new AlertDialog.Builder的时候没有指定主题，

 AlertDialog commedialog = new AlertDialog.Builder(WalkieTalkieActivity.this)

我们可以在new AlertDialog.Builder的时候指定一个主题，如下所示：

 

 AlertDialog commedialog = new AlertDialog.Builder(
                     WalkieTalkieActivity.this,AlertDialog.THEME_HOLO_DARK)

 

完整代码如下：

 AlertDialog commedialog = new AlertDialog.Builder(
                     WalkieTalkieActivity.this,AlertDialog.THEME_HOLO_DARK)
                     .setTitle(title)
                     .setView(vi_nolong)
                     .setPositiveButton(
                             WalkieTalkieActivity.this.getResources().getString(R.string.ok),
                             new DialogInterface.OnClickListener() {
                                 public void onClick(DialogInterface dialog, int arg1) {

                                     int j = mSelectedGroupNum + 1;
                                     int power_last = mIntercomSharePrefs.getInt("CurrentPower_"+j,0);
                                     Log.i("wxj", "btn_power CurrentPower_"+j+" :" + power_last);
                                     if (power_last == 1) {
                                         mEditor.putInt("CurrentPower_"+j,0).commit();
                                         mIntercom.setPowerLevel(0);
                                         btn_power.setBackgroundResource(R.drawable.power_high);

                                     } else if (power_last == 0) {
                                         mEditor.putInt("CurrentPower_"+j,1).commit();
                                         mIntercom.setPowerLevel(1);
                                         btn_power.setBackgroundResource(R.drawable.power_low);
                                     }
                                     dialog.dismiss();
                                     ((ViewGroup) vi_nolong.getParent()).removeView(vi_nolong);
                                 }
                             })
                     .setNegativeButton(
                             WalkieTalkieActivity.this.getResources().getString(R.string.cancel),
                             new DialogInterface.OnClickListener() {
                                 public void onClick(DialogInterface dialog,
                                         int whichButton) {

                                     dialog.dismiss();
                                     ((ViewGroup) vi_nolong.getParent()).removeView(vi_nolong);
                                 }
                             }).create();
             commedialog.setCanceledOnTouchOutside(false);
             commedialog.show();

 

这样的话就指定了一个黑色背景的主题，这样在系统语言为英语的时候，背景也是黑色的，如下所示：

在系统语言为中文的时候，背景也是黑色的，如下所示：

 

====================================================================================================================================

下面从源码角度来看看到底是怎么回事，查看AlertDialog.Build代码如下：

 /**
   * Constructor using a context for this builder and the {@link AlertDialog} it creates.
   */
  public Builder(Context context) {
      this(context, resolveDialogTheme(context, 0));
  }

  /**
   * Constructor using a context and theme for this builder and
   * the {@link AlertDialog} it creates.  The actual theme
   * that an AlertDialog uses is a private implementation, however you can
   * here supply either the name of an attribute in the theme from which
   * to get the dialog's style (such as {@link android.R.attr#alertDialogTheme}
   * or one of the constants
   * {@link AlertDialog#THEME_TRADITIONAL AlertDialog.THEME_TRADITIONAL},
   * {@link AlertDialog#THEME_HOLO_DARK AlertDialog.THEME_HOLO_DARK}, or
   * {@link AlertDialog#THEME_HOLO_LIGHT AlertDialog.THEME_HOLO_LIGHT}.
   */
  public Builder(Context context, int theme) {
      P = new AlertController.AlertParams(new ContextThemeWrapper(
              context, resolveDialogTheme(context, theme)));
      mTheme = theme;
  }

resolveDialogTheme(Context context, int resid) 代码如下：

 

 static int resolveDialogTheme(Context context, int resid) {
     if (resid == THEME_TRADITIONAL) {
         return com.android.internal.R.style.Theme_Dialog_Alert;
     } else if (resid == THEME_HOLO_DARK) {
         return com.android.internal.R.style.Theme_Holo_Dialog_Alert;
     } else if (resid == THEME_HOLO_LIGHT) {
         return com.android.internal.R.style.Theme_Holo_Light_Dialog_Alert;
     } else if (resid == THEME_DEVICE_DEFAULT_DARK) {
         return com.android.internal.R.style.Theme_DeviceDefault_Dialog_Alert;
     } else if (resid == THEME_DEVICE_DEFAULT_LIGHT) {
         return com.android.internal.R.style.Theme_DeviceDefault_Light_Dialog_Alert;
     } else if (resid >= 0x01000000) {   // start of real resource IDs.
         return resid;
     } else {
         TypedValue outValue = new TypedValue();
         context.getTheme().resolveAttribute(com.android.internal.R.attr.alertDialogTheme,
                 outValue, true);
         return outValue.resourceId;
     }
 }

几个主题的值为：

 /**
     * Special theme constant for {@link #AlertDialog(Context, int)}: use
     * the traditional (pre-Holo) alert dialog theme.
     */
    public static final int THEME_TRADITIONAL = 1;

    /**
     * Special theme constant for {@link #AlertDialog(Context, int)}: use
     * the holographic alert theme with a dark background.
     */
    public static final int THEME_HOLO_DARK = 2;

    /**
     * Special theme constant for {@link #AlertDialog(Context, int)}: use
     * the holographic alert theme with a light background.
     */
    public static final int THEME_HOLO_LIGHT = 3;

    /**
     * Special theme constant for {@link #AlertDialog(Context, int)}: use
     * the device's default alert theme with a dark background.
     */
    public static final int THEME_DEVICE_DEFAULT_DARK = 4;

    /**
     * Special theme constant for {@link #AlertDialog(Context, int)}: use
     * the device's default alert theme with a dark background.
     */
    public static final int THEME_DEVICE_DEFAULT_LIGHT = 5;

由此可见，当我们不指定主题的时候，

 AlertDialog commedialog = new AlertDialog.Builder(WalkieTalkieActivity.this)

系统给我们的主题是：

 TypedValue outValue = new TypedValue();
            context.getTheme().resolveAttribute(com.android.internal.R.attr.alertDialogTheme,
                    outValue, true);
            return outValue.resourceId;

 

====================================================================================================================================

下面分别来测试一下这几个主题

主题为：AlertDialog.THEME_HOLO_LIGHT

 AlertDialog commedialog = new AlertDialog.Builder(
                     WalkieTalkieActivity.this,AlertDialog.THEME_HOLO_LIGHT)

 

主题为：AlertDialog.THEME_TRADITIONAL

 AlertDialog commedialog = new AlertDialog.Builder(
                     WalkieTalkieActivity.this,AlertDialog.THEME_TRADITIONAL)

 

主题为：AlertDialog.THEME_DEVICE_DEFAULT_DARK

 AlertDialog commedialog = new AlertDialog.Builder(
                     WalkieTalkieActivity.this,AlertDialog.THEME_DEVICE_DEFAULT_DARK)

 

主题为：AlertDialog.THEME_DEVICE_DEFAULT_LIGHT

 AlertDialog commedialog = new AlertDialog.Builder(
                     WalkieTalkieActivity.this,AlertDialog.THEME_DEVICE_DEFAULT_LIGHT)