Android EditText被軟鍵盤遮擋問題(問題記錄)

前言：這個問題在目前的開發生涯中，令我比較深刻，以至于過去快1年了，我還記憶猶新，在此記錄一下，

場景：大約在1年前，當時負責的一個WMS倉儲管理APP(Kotlin專案)，線上突然反饋了“輸入框被軟鍵盤遮擋的問題”，接手問題后，使用線下物聯網定制手持機除錯復現中，系統版本為Android 8.0，

問題現象：目前暫時沒有設備，因而無法復現，故暫時不上gif圖，這邊口頭描述一下：在頁面中間部分有一個輸入框，點擊輸入框喚出軟鍵盤時，輸入框被軟鍵盤遮擋了一部分，這一部分就看不到了，遮擋程度取決于輸入框位置，可能被遮擋部分或被全遮擋；位于頁面上方的，比如搜索框之類的，不受影響；對于軟體盤輸入事件不影響，輸入的資料還是能拿到的，

解決：當時遇到這個問題，比較懵逼，且也找不到相關資料，只能不斷試錯，通過猜測進行嘗試，中間也橫向對比了其他專案，在該手持機上跑；轉折點在“部分遮擋”情況下，部分遮擋的時候，輸入的文字、游標都展示了一半，就感覺是可能是渲染問題，于是開啟了專案全域硬體加速進行嘗試，最終解決了問題，

<application>
    ...
    android:hardwareAccelerated="true"
</application>

總結：一般沒有沖突或其它連帶問題情況下，硬體加速優先還是開啟比較好，如果遇到專案不得不開啟硬體加速，而其他地方開啟硬體加速會出現問題的情況，則可以結合Application、Activity、Window、View這四個層面對硬體加速打開或關閉，

View開啟硬體加速方法view.setLayerType()，原始碼如下：

/**
     * <p>Specifies the type of layer backing this view. The layer can be
     * {@link #LAYER_TYPE_NONE}, {@link #LAYER_TYPE_SOFTWARE} or
     * {@link #LAYER_TYPE_HARDWARE}.</p>
     *
     * <p>A layer is associated with an optional {@link android.graphics.Paint}
     * instance that controls how the layer is composed on screen. The following
     * properties of the paint are taken into account when composing the layer:</p>
     * <ul>
     * <li>{@link android.graphics.Paint#getAlpha() Translucency (alpha)}</li>
     * <li>{@link android.graphics.Paint#getXfermode() Blending mode}</li>
     * <li>{@link android.graphics.Paint#getColorFilter() Color filter}</li>
     * </ul>
     *
     * <p>If this view has an alpha value set to < 1.0 by calling
     * {@link #setAlpha(float)}, the alpha value of the layer's paint is superseded
     * by this view's alpha value.</p>
     *
     * <p>Refer to the documentation of {@link #LAYER_TYPE_NONE},
     * {@link #LAYER_TYPE_SOFTWARE} and {@link #LAYER_TYPE_HARDWARE}
     * for more information on when and how to use layers.</p>
     *
     * @param layerType The type of layer to use with this view, must be one of
     *        {@link #LAYER_TYPE_NONE}, {@link #LAYER_TYPE_SOFTWARE} or
     *        {@link #LAYER_TYPE_HARDWARE}
     * @param paint The paint used to compose the layer. This argument is optional
     *        and can be null. It is ignored when the layer type is
     *        {@link #LAYER_TYPE_NONE}
     *
     * @see #getLayerType()
     * @see #LAYER_TYPE_NONE
     * @see #LAYER_TYPE_SOFTWARE
     * @see #LAYER_TYPE_HARDWARE
     * @see #setAlpha(float)
     *
     * @attr ref android.R.styleable#View_layerType
     */
    public void setLayerType(int layerType, @Nullable Paint paint) {
        if (layerType < LAYER_TYPE_NONE || layerType > LAYER_TYPE_HARDWARE) {
            throw new IllegalArgumentException("Layer type can only be one of: LAYER_TYPE_NONE, "
                    + "LAYER_TYPE_SOFTWARE or LAYER_TYPE_HARDWARE");
        }

        boolean typeChanged = mRenderNode.setLayerType(layerType);

        if (!typeChanged) {
            setLayerPaint(paint);
            return;
        }

        if (layerType != LAYER_TYPE_SOFTWARE) {
            // Destroy any previous software drawing cache if present
            // NOTE: even if previous layer type is HW, we do this to ensure we've cleaned up
            // drawing cache created in View#draw when drawing to a SW canvas.
            destroyDrawingCache();
        }

        mLayerType = layerType;
        mLayerPaint = mLayerType == LAYER_TYPE_NONE ? null : paint;
        mRenderNode.setLayerPaint(mLayerPaint);

        // draw() behaves differently if we are on a layer, so we need to
        // invalidate() here
        invalidateParentCaches();
        invalidate(true);
    }

Window開啟硬體加速：

window.setFlags(
                WindowManager.LayoutParams.FLAG_HARDWARE_ACCELERATED,
                WindowManager.LayoutParams.FLAG_HARDWARE_ACCELERATED)

引數解釋如下：

/**
         * <p>Indicates whether this window should be hardware accelerated.
         * Requesting hardware acceleration does not guarantee it will happen.</p>
         *
         * <p>This flag can be controlled programmatically <em>only</em> to enable
         * hardware acceleration. To enable hardware acceleration for a given
         * window programmatically, do the following:</p>
         *
         * <pre>
         * Window w = activity.getWindow(); // in Activity's onCreate() for instance
         * w.setFlags(WindowManager.LayoutParams.FLAG_HARDWARE_ACCELERATED,
         *         WindowManager.LayoutParams.FLAG_HARDWARE_ACCELERATED);
         * </pre>
         *
         * <p>It is important to remember that this flag <strong>must</strong>
         * be set before setting the content view of your activity or dialog.</p>
         *
         * <p>This flag cannot be used to disable hardware acceleration after it
         * was enabled in your manifest using
         * {@link android.R.attr#hardwareAccelerated}. If you need to selectively
         * and programmatically disable hardware acceleration (for automated testing
         * for instance), make sure it is turned off in your manifest and enable it
         * on your activity or dialog when you need it instead, using the method
         * described above.</p>
         *
         * <p>This flag is automatically set by the system if the
         * {@link android.R.attr#hardwareAccelerated android:hardwareAccelerated}
         * XML attribute is set to true on an activity or on the application.</p>
         */
        public static final int FLAG_HARDWARE_ACCELERATED = 0x01000000;