dialog中hide、dismiss、cancel方法的区别

dialog中hide、dismiss、cancel方法的区别

主要我之前用的时候不知道dismiss和cancel有啥区别。。。然后今天想起来了就去查了一下，顺便记下来备忘。

dismiss:大概就是删除视图，调用Onstop回调，并把mShowing置为false。

    void dismissDialog() {if (mDecor == null || !mShowing) {return;}if (mWindow.isDestroyed()) {Log.e(TAG, "Tried to dismissDialog() but the Dialog's window was already destroyed!");return;}try {veViewImmediate(mDecor);} finally {if (mActionMode != null) {mActionMode.finish();}mDecor = null;mWindow.closeAllPanels();onStop();mShowing = false;sendDismissMessage();}}

cancel：也调用了dismiss，只不过先判断了mCancelMessage是否为空

    @Overridepublic void cancel() {if (!mCanceled && mCancelMessage != null) {mCanceled = true;Message.obtain(mCancelMessage).sendToTarget();}dismiss();}

mCancelMessage实际上是把listener封装成obj的Message

    public void setOnCancelListener(@Nullable OnCancelListener listener) {if (mCancelAndDismissTaken != null) {throw new IllegalStateException("OnCancelListener is already taken by "+ mCancelAndDismissTaken + " and can not be replaced.");}if (listener != null) {mCancelMessage = mListenersHandler.obtainMessage(CANCEL, listener);} else {mCancelMessage = null;}}

hide：这是干嘛的。。。隐藏起来又不销毁，有啥用？万一后面忘了呢，销毁Activity的时候就会报错：android.view.WindowLeaked: Activity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorViewthat was originally added here，所以建议不用。

    public void hide() {if (mDecor != null) {mDecor.setVisibility(View.GONE);}}

 总结：

建议用dismiss，这个比cancel少一个判断，一般来说是够用了，当然如果你有CancelListener的话就用cancel。。。