摘要：在這個類中第一行就定義了如下變量的功能的具體實現(xiàn)都在這個內(nèi)部封裝修改按鈕顏色這里的參數(shù)有三種類型傳入對應(yīng)的參數(shù)即可得到對應(yīng)的這種方式只能設(shè)置按鈕的顏色而無法設(shè)置標題顏色需要注意的是這個方法必須在或者方法之后調(diào)用查看官方注釋的構(gòu)造函數(shù)如下這里

在這個類中第一行就定義了如下變量:

final AlertController mAlert;

AlertDialog的功能的具體實現(xiàn)都在這個AlertController內(nèi)部封裝.

public Button getButton(int whichButton) {
        return mAlert.getButton(whichButton);
    }

這里的參數(shù)whichButton有三種類型:

DialogInterface.BUTTON_POSITIVE

DialogInterface.BUTTON_NEGATIVE

DialogInterface.BUTTON_NEUTRAL

傳入對應(yīng)的參數(shù)即可得到對應(yīng)的Button

Button btnPositive = (Button)AlertDialog.getButton(DialogInterface.BUTTON_POSITIVE);
btnPositive.setTextColor(color);

這種方式只能設(shè)置按鈕的顏色,而無法設(shè)置標題顏色

需要注意的是這個方法必須在AlertDialog.show()或者AlertDialog.create()方法之后調(diào)用
查看官方注釋

/**
     * Gets one of the buttons used in the dialog. Returns null if the specified
     * button does not exist or the dialog has not yet been fully created (for
     * example, via {@link #show()} or {@link #create()}).
     *
     * @param whichButton The identifier of the button that should be returned.
     *                    For example, this can be
     *                    {@link DialogInterface#BUTTON_POSITIVE}.
     * @return The button from the dialog, or null if a button does not exist.
     */
    public Button getButton(int whichButton) {
        return mAlert.getButton(whichButton);
    }

AlertDialog的構(gòu)造函數(shù)如下:

protected AlertDialog(@NonNull Context context, @StyleRes int themeResId) {
        super(context, resolveDialogTheme(context, themeResId));
        mAlert = new AlertController(getContext(), this, getWindow());
    }

這里初始化了AlertController,并傳入了getWindow(),這個getWindow()是AlertDialog繼承自Dialog的方法.方法如下:

#Dialog.getWindow()
 public @Nullable Window getWindow() {
        return mWindow;
    }

將這個window對象傳入AlertController后,在AlertController源碼中可以看到對話框標題和按鈕的id,并通過Window.findViewById(id)獲取對應(yīng)的View.
所以這里可以這樣得到對話框的標題和按鈕:

//標題
TextView tvTitle = (TextView)AlertDialog.getWindow().findViewById(R.id.alertTitle);
//按鈕
Button btnPositive = (Button)AlertDialog.getWindow().findViewById(R.id.button1);

然后設(shè)置所需要的顏色就可以了.這種方法可以修改Dialog的所有設(shè)置了id的控件的字體顏色.

3.1 首先拿到AlertController對象

 Field mAlert = AlertDialog.class.getDeclaredField("mAlert");
 mAlert.setAccessible(true);
 Object controller =  mAlert.get(dialog);

在AlertController內(nèi)部查找到需要更改字體顏色的標題和按鈕

Button mButtonPositive;
Button mButtonNegative;
Button mButtonNeutral;
private TextView mTitleView;
private TextView mMessageView;
然后通過反射獲取對應(yīng)控件,修改控件顏色即可

  Field mTitleView = controller.getClass().getDeclaredField("mTitleView");
  mTitleView.setAccessible(true);
  TextView tvTitle = (TextView) mTitleView.get(controller);
  tvTitle.setTextColor(Color.GREEN);//更改標題的顏色

Window window = dialog.getWindow();
 WindowManager.LayoutParams lp = window.getAttributes();
lp.gravity = Gravity.BOTTOM;
lp.x = 100;
lp.y = 100;
window.setAttributes(lp);

這里要注意的是,WindowManager.LayoutParams的x和y坐標,看源碼注釋如下:

  /**
         * X position for this window.  With the default gravity it is ignored.
         * When using {@link Gravity#LEFT} or {@link Gravity#START} or {@link Gravity#RIGHT} or
         * {@link Gravity#END} it provides an offset from the given edge.
         */
        @ViewDebug.ExportedProperty
        public int x;

        /**
         * Y position for this window.  With the default gravity it is ignored.
         * When using {@link Gravity#TOP} or {@link Gravity#BOTTOM} it provides
         * an offset from the given edge.
         */
        @ViewDebug.ExportedProperty
        public int y;

如果lp.gravity是默認的,那么x和y即使設(shè)置了也是無效的.因此x和y需要和lp.gravity搭配使用才有效果.當然lp.gravity也可以多帶帶使用.