更改组件的属性

Question

我想改变一个组件的某些属性，比如旋转。

我这样试试：

package com.dev.moritz.colora;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;
import android.view.WindowManager;
import android.widget.ImageView;
import android.widget.RelativeLayout;
import android.widget.TextView;
import android.widget.Toast;

public class gameActivity extends AppCompatActivity{

    public ImageView square;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);

        square = (ImageView) findViewById(R.id.game_square);
        setContentView(R.layout.activity_game);

        square.setRotation(square.getRotation() + 90);
    }

    public void layout_click(View v) {

    }

}

但是当我开始这个应用程序崩溃时。没有旋转一切都有效，所以存在问题。 我该怎么办？

Moritz的

Answer 1

尝试在视图

之前绑定setContentView()

    setContentView(R.layout.activity_game);
    square = (ImageView) findViewById(R.id.game_square);
    square.setRotation(square.getRotation() + 90);

<强>代替

    square = (ImageView) findViewById(R.id.game_square);
    setContentView(R.layout.activity_game);
    square.setRotation(square.getRotation() + 90);