Question

我想通过android源来了解错误原因。我的安卓设备version 4.4.4与API 19相同。我下载了API级别19（通过sdk管理器）的源代码，并希望找到导致错误的代码在logcat中我有错误：

12-16 16:51:03.790: E/AndroidRuntime(10349): java.lang.NullPointerException
12-16 16:51:03.790: E/AndroidRuntime(10349):    at android.widget.TextView.checkForRelayout(TextView.java:6596)
12-16 16:51:03.790: E/AndroidRuntime(10349):    at android.widget.TextView.onRtlPropertiesChanged(TextView.java:8716)
12-16 16:51:03.790: E/AndroidRuntime(10349):    at android.view.View.resolvePadding(View.java:12538)

但问题是TextView类的第6596行是：

} else {

第8716行是评论。所以cources不对应错误。如何找到正确的来源？

此外，如果检入设备Build.VERSION.SDK_INT is 19。设备 - Sony Xperia tablet。

完整的logcat 12-16 17:30:43

.401: E/AndroidRuntime(19327): java.lang.NullPointerException
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.widget.TextView.checkForRelayout(TextView.java:6596)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.widget.TextView.onRtlPropertiesChanged(TextView.java:8716)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.view.View.resolvePadding(View.java:12538)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.view.View.resolveRtlPropertiesIfNeeded(View.java:12289)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.view.View.measure(View.java:16639)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at com.cooperok.gui.views.tablefixheader.TableFixHeaders.makeView(TableFixHeaders.java:741)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at com.cooperok.gui.views.tablefixheader.TableFixHeaders.makeAndSetup(TableFixHeaders.java:698)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at com.cooperok.gui.views.tablefixheader.TableFixHeaders.onLayout(TableFixHeaders.java:601)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.view.View.layout(View.java:14965)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.view.ViewGroup.layout(ViewGroup.java:4631)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1671)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1525)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.widget.LinearLayout.onLayout(LinearLayout.java:1434)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.view.View.layout(View.java:14965)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.view.ViewGroup.layout(ViewGroup.java:4631)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.widget.FrameLayout.layoutChildren(FrameLayout.java:453)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.widget.FrameLayout.onLayout(FrameLayout.java:388)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.view.View.layout(View.java:14965)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.view.ViewGroup.layout(ViewGroup.java:4631)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.widget.FrameLayout.layoutChildren(FrameLayout.java:453)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.widget.FrameLayout.onLayout(FrameLayout.java:388)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.view.View.layout(View.java:14965)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.view.ViewGroup.layout(ViewGroup.java:4631)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1671)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1525)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.widget.LinearLayout.onLayout(LinearLayout.java:1434)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.view.View.layout(View.java:14965)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.view.ViewGroup.layout(ViewGroup.java:4631)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.widget.FrameLayout.layoutChildren(FrameLayout.java:453)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.widget.FrameLayout.onLayout(FrameLayout.java:388)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.view.View.layout(View.java:14965)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.view.ViewGroup.layout(ViewGroup.java:4631)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1671)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1525)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.widget.LinearLayout.onLayout(LinearLayout.java:1434)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.view.View.layout(View.java:14965)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.view.ViewGroup.layout(ViewGroup.java:4631)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.widget.FrameLayout.layoutChildren(FrameLayout.java:453)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.widget.FrameLayout.onLayout(FrameLayout.java:388)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.view.View.layout(View.java:14965)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.view.ViewGroup.layout(ViewGroup.java:4631)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:1987)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1744)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1000)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5622)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.view.Choreographer$CallbackRecord.run(Choreographer.java:761)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.view.Choreographer.doCallbacks(Choreographer.java:574)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.view.Choreographer.doFrame(Choreographer.java:544)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:747)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.os.Handler.handleCallback(Handler.java:733)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.os.Handler.dispatchMessage(Handler.java:95)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.os.Looper.loop(Looper.java:212)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at android.app.ActivityThread.main(ActivityThread.java:5135)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at java.lang.reflect.Method.invokeNative(Native Method)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at java.lang.reflect.Method.invoke(Method.java:515)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:878)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
12-16 17:30:43.401: E/AndroidRuntime(19327):    at dalvik.system.NativeStart.main(Native Method)

Answer 1

要找到合适的来源，您应该拥有一台Google Nexus设备 - 纯Android设备。

制造商为其设备更改了Android的来源。它会导致logcat上出现错误的行号。

Answer 2

为了解决我的问题，我查看了原始android源代码并发现NullPointerException只有两个可能的变体，所以很容易猜到问题出在哪里

/**
 * Check whether entirely new text requires a new view layout
 * or merely a new text layout.
 */
private void checkForRelayout() {
    // If we have a fixed width, we can just swap in a new text layout
    // if the text height stays the same or if the view height is fixed.

    if ((mLayoutParams.width != LayoutParams.WRAP_CONTENT ||
            (mMaxWidthMode == mMinWidthMode && mMaxWidth == mMinWidth)) &&
            (mHint == null || mHintLayout != null) &&
            (mRight - mLeft - getCompoundPaddingLeft() - getCompoundPaddingRight() > 0)) {
        // Static width, so try making a new text layout.

        int oldht = mLayout.getHeight();
        int want = mLayout.getWidth();
        int hintWant = mHintLayout == null ? 0 : mHintLayout.getWidth();

        /*
         * No need to bring the text into view, since the size is not
         * changing (unless we do the requestLayout(), in which case it
         * will happen at measure).
         */
        makeNewLayout(want, hintWant, UNKNOWN_BORING, UNKNOWN_BORING,
                      mRight - mLeft - getCompoundPaddingLeft() - getCompoundPaddingRight(),
                      false);

        if (mEllipsize != TextUtils.TruncateAt.MARQUEE) {
            // In a fixed-height view, so use our new text layout.
            if (mLayoutParams.height != LayoutParams.WRAP_CONTENT &&
                mLayoutParams.height != LayoutParams.MATCH_PARENT) {
                invalidate();
                return;
            }

            // Dynamic height, but height has stayed the same,
            // so use our new text layout.
            if (mLayout.getHeight() == oldht &&
                (mHintLayout == null || mHintLayout.getHeight() == oldht)) {
                invalidate();
                return;
            }
        }

        // We lose: the height has changed and we have a dynamic height.
        // Request a new view layout using our new text layout.
        requestLayout();
        invalidate();
    } else {
        // Dynamic width, so we have no choice but to request a new
        // view layout with a new text layout.
        nullLayouts();
        requestLayout();
        invalidate();
    }
}

在我的情况下，TextView是以编程方式创建的，并且mLayoutParams为null，因此通过设置LayoutParams来查看问题。
但这很糟糕，供应商可以更改Android源代码并且不显示这些更改（实际上我没有找到有关索尼的任何信息）。我以为他们只改变内核。

如何为Android设备找到正确的来源？

2 个答案: