Android 软键盘不能弹出

记录一次软键盘不能调出来的问题

一、前提条件

设置其所在Activity，AndroidManifest.xml属性 android:windowSoftInputMode=“stateVisible|adjustResize”
EditText点击本身的话，据系统规则会调用起软键盘

二、操作表现

点击EditText，系统没有调用软键盘，不知为何原因？
故手动调用软键盘看能不能调用起来

InputMethodManager imm = (InputMethodManager) getSystemService(INPUT_METHOD_SERVICE);
imm.showSoftInput(mContentEditText, InputMethodManager.SHOW_FORCED);

发现仍然不能调用起软键盘，故Debug showSoftInput的源代码

三、追踪问题

1、只有Debug showSoftInput源代码，最终定位到

public boolean showSoftInput(View view, int flags, ResultReceiver resultReceiver) {checkFocus();synchronized (mH) {if (mServedView != view && (mServedView == null|| !mServedView.checkInputConnectionProxy(view))) {return false;}try {return mService.showSoftInput(mClient, flags, resultReceiver);} catch (RemoteException e) {throw e.rethrowFromSystemServer();}}}

发现传过来的view是EditView，没有任何问题，问题在mServedView != view返回为true，mServedView竟然为另外的view，故不能向下调用mService.showSoftInput(mClient, flags, resultReceiver)去启用软键盘

2、寻找mServedView的赋值位置，

private boolean checkFocusNoStartInput(boolean forceNewFocus) {// This is called a lot, so short-circuit before locking.if (mServedView == mNextServedView && !forceNewFocus) {return false;}final ControlledInputConnectionWrapper ic;synchronized (mH) {if (mServedView == mNextServedView && !forceNewFocus) {return false;}if (DEBUG) Log.v(TAG, "checkFocus: view=" + mServedView+ " next=" + mNextServedView+ " forceNewFocus=" + forceNewFocus+ " package="+ (mServedView != null ? mServedView.getContext().getPackageName() : "<none>"));if (mNextServedView == null) {finishInputLocked();// In this case, we used to have a focused view on the window,// but no longer do.  We should make sure the input method is// no longer shown, since it serves no purpose.closeCurrentInput();return false;}ic = mServedInputConnectionWrapper;mServedView = mNextServedView;mCurrentTextBoxAttribute = null;mCompletions = null;mServedConnecting = true;}if (ic != null) {ic.finishComposingText();}return true;}

最终定位于Activity中EditView的焦点失去，导致mServedView重新被赋值，mServedView = mNextServedView;
所以… …