我的Android進階之旅------)Android中Dialog系統樣式講解

今天在維護公司的一個APP的時候,有如下場景。

彈出一個AlertDialog的時候，在系統語言是中文的時候，如下所示：

彈出一個AlertDialog的時候，在系統語言是English的時候，如下所示：

可以發現在系統語言為英語的時候，對話框中的白色文字已經完全看不清楚，對話框的背景顏色也變成了白色。因此需要修改對話框的主題。

 

修改之前代碼如下：

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();

 

 

可以發現，new AlertDialog.Builder的時候沒有指定主題，

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

我們可以在new AlertDialog.Builder的時候指定一個主題，如下所示：

 

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

 

完整代碼如下：

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();

 

這樣的話就指定了一個黑色背景的主題，這樣在系統語言為英語的時候，背景也是黑色的，如下所示：

在系統語言為中文的時候，背景也是黑色的，如下所示：

 

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

下面從源碼角度來看看到底是怎麼回事，查看AlertDialog.Build代碼如下：

       /**
         * 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) 代碼如下：

 

    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;
        }
    }

幾個主題的值為：

 /**
     * 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;

由此可見，當我們不指定主題的時候，

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

系統給我們的主題是：

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

 

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

下面分別來測試一下這幾個主題

主題為：AlertDialog.THEME_HOLO_LIGHT

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

 

主題為：AlertDialog.THEME_TRADITIONAL

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

 

主題為：AlertDialog.THEME_DEVICE_DEFAULT_DARK

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

 

主題為：AlertDialog.THEME_DEVICE_DEFAULT_LIGHT

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