dialog的setCancelable与setCanceledOnTouchOutside的区别、dismiss与cancel和hide区别、异常等

看源码：

/**
 * Sets whether this dialog is cancelable with the
 * {@link KeyEvent#KEYCODE_BACK BACK} key. //点击物理返回键是否可取消dialog
 */
public void setCancelable(boolean flag) {
    mCancelable = flag;
}

/**
 * Sets whether this dialog is canceled when touched outside the window's
 * bounds. If setting to true, the dialog is set to be cancelable if not
 * already set.
 * 
 * @param cancel Whether the dialog should be canceled when touched outside
 *            the window.   //点击dialog之外 是否可取消
 */
public void setCanceledOnTouchOutside(boolean cancel) {
    if (cancel && !mCancelable) {
        mCancelable = true;
    }

    mWindow.setCloseOnTouchOutside(cancel);
}

/**
 * Cancel the dialog.  This is essentially the same as calling {@link #dismiss()}, but it will
 * also call your {@link DialogInterface.OnCancelListener} (if registered).
 *  // 取消dialog ，和dismiss相同，但cancel会回调DialogInterface.OnCancelListener
 */
@Override
public void cancel() {
    if (!mCanceled && mCancelMessage != null) {
        mCanceled = true;
        // Obtain a new message so this dialog can be re-used
        Message.obtain(mCancelMessage).sendToTarget();
    }
    dismiss();
}

/**
 * Set a listener to be invoked when the dialog is canceled.    //设置监听取消dialog
 *
 * <p>This will only be invoked when the dialog is canceled.
 * Cancel events alone will not capture all ways that
 * the dialog might be dismissed. If the creator needs
 * to know when a dialog is dismissed in general, use
 * {@link #setOnDismissListener}.</p>
 * 
 * @param listener The {@link DialogInterface.OnCancelListener} to use.
 */
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 the dialog, but do not dismiss it.  //隐藏dialog（设置为Gone），但是不dismiss
 *      //hide只是把对话框里的DecorView设置为不可见，并没有从Window移除掉这个DecorView。
 */
public void hide() {
    if (mDecor != null) {
        mDecor.setVisibility(View.GONE);
    }
}

/**
 * Dismiss this dialog, removing it from the screen. This method can be
 * invoked safely from any thread.  Note that you should not override this
 * method to do cleanup when the dialog is dismissed, instead implement
 * that in {@link #onStop}. //从屏幕移除，可以任意线程使用，在onstop中移除
 *      //dismiss可以在任何线程调用，但是最好不要覆写dismiss方法，实在需要就在onStop里去dismiss。
 */
@Override
public void dismiss() {
    if (Looper.myLooper() == mHandler.getLooper()) {
        dismissDialog();
    } else {
        mHandler.post(mDismissAction);
    }
}

dismiss、cancel和hide区别

dismiss、cancel两者效果都是一样的，其实看下源码就知道cancel肯定会去调dismiss的，如果调用的cancel的话就可以监听DialogInterface.OnCancelListener。

hide只是隐藏了对话框并没有销毁，如果打算用这方法来灭掉对话框就会出现问题，在Activity销毁的时候就会出现崩溃日志了，因为Activity销毁时是需要把对话框都关闭掉的。

setCancelable与setCanceledOnTouchOutside的区别

setCancelable : 点击物理返回键是否可关闭弹框

setCanceledOnTouchOutside： 点击弹框外 是否可关闭弹框

异常：

not attached to window manager

解决：

ondestroy中要关闭dialog：

  @Override
    protected void onDestroy() {
        if (progressDialog != null && progressDialog.isShowing()) {
            progressDialog.dismiss();
            progressDialog = null;
        }
        super.onDestroy();
    }

示例如下：

public class TestActivity extends AppCompatActivity {

    private Dialog progressDialog;

    @Override
    protected void onPause() {
        super.onPause();

        if (progressDialog != null && progressDialog.isShowing()) {
            progressDialog.dismiss();
        }
    }

    @Override
    protected void onDestroy() {
        if (progressDialog != null && progressDialog.isShowing()) {
            progressDialog.dismiss();
        }
        progressDialog = null;

        super.onDestroy();
    }

    protected void showLoading() {
        if (progressDialog == null) {
            progressDialog = new Dialog(this, R.style.progress_dialog);
        }

        if (progressDialog.isShowing()) {
            progressDialog.dismiss();
        }
        progressDialog.setContentView(R.layout.logindialog);
        progressDialog.setCancelable(true);
        progressDialog.setCanceledOnTouchOutside(false);
        Window window = progressDialog.getWindow();
        if (window != null) {
            window.setBackgroundDrawableResource(android.R.color.transparent);
        }
        progressDialog.show();
    }

    protected void dismissLoading() {
        if (progressDialog != null && progressDialog.isShowing()) {
            progressDialog.dismiss();
        }
    }

}