LayoutParams崩溃应用程序

Question

我有一个奇怪的问题。

使用此代码，在“错误5”之前尝试制作新的LayoutParams时会崩溃。

    getScreenWidthAndHeight();
    Log.d("Error", "1");
    eField = (EditText)findViewById(R.id.emailField);
    Log.d("Error", "2");
    pField = (EditText)findViewById(R.id.passwordField);
    Log.d("Error", "3");
    signInButton = (Button)findViewById(R.id.singInButton); 
    Log.d("Error", "4");
    RelativeLayout.LayoutParams lParamsForEField = new RelativeLayout.LayoutParams(eField.getWidth(), eField.getHeight());
    Log.d("Error", "5");
    RelativeLayout.LayoutParams lParamsForPField = (LayoutParams) pField.getLayoutParams();
    Log.d("Error", "6");
    RelativeLayout.LayoutParams lParamsForSignInButton = (LayoutParams) signInButton.getLayoutParams();

CLOSED

引起：java.lang.NullPointerException

问题在于在为内容视图设置布局之前尝试查找元素。