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都在這個內部封裝修改按鈕顏色這里的參數有三種類型傳入對應的參數即可得到對應的這種方式只能設置按鈕的顏色而無法設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用查看官方注釋的構造函數如下這里

在這個類中第一行就定義了如下變量:

final AlertController mAlert;

AlertDialog的功能的具體實現都在這個AlertController內部封裝.

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

這里的參數whichButton有三種類型:

DialogInterface.BUTTON_POSITIVE

DialogInterface.BUTTON_NEGATIVE

DialogInterface.BUTTON_NEUTRAL

傳入對應的參數即可得到對應的Button

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

這種方式只能設置按鈕的顏色,而無法設置標題顏色

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的構造函數如下:

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);

然后設置所需要的顏色就可以了.這種方法可以修改Dialog的所有設置了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.