的Android程序運行時錯誤

Question

我在做什麼錯在下面的代碼編譯的代碼，但在安裝時給出了一個錯誤

package com.app.newapp; 

    import android.app.Activity; 
    import android.os.Bundle; 
    import android.view.View; 
    import android.view.View.OnClickListener; 
    import android.widget.Button; 
    import android.widget.EditText; 
    import android.widget.ImageView; 
    import android.widget.TextView; 

    public class NewappActivity extends Activity { 
    /** Called when the activity is first created. */ 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 

     super.onCreate(savedInstanceState); 
     setContentView(R.layout.main); 
     ImageView.setVisibilty(View.INVISIBLE); 
     Button btn=(Button) findViewById(R.id.enter); 
     btn.setOnClickListener(new OnClickListener() { 

      @Override 
      public void onClick(View v) { 
       // TODO Auto-generated method stub 
       String pwd="pd"; 
       EditText et=(EditText) findViewById(R.id.pwd); 
       if(et.getText().toString().equalsIgnoreCase(pwd)) 
       { 
        ImageView iv=(ImageView) findViewById(R.id.im1); 
        ImageView.setVisibilty(View.VISIBLE); 
       } 

      } 
     }); 
    } 

Answer 1

請嘗試以下的事情

setContentView(R.layout.main); 
ImageView imagvw1=(ImageView) findViewById(R.id.Imageviewname); 
imagvw1.setVisibilty(View.INVISIBLE); 

Answer 2

是的，這是正常的得到一個錯誤。

super.onCreate(savedInstanceState); 
setContentView(R.layout.main); 
**ImageView.setVisibilty(View.INVISIBLE);**

怎麼樣的圖像視圖？你有這樣的例子嗎？或者是空引用？

Answer 3

你沒有兩個錯誤 1）初始化圖像視圖 2）設置能見度爲ImageView的唯一對象。

用下面的代碼

import android.app.Activity; 
    import android.os.Bundle; 
    import android.view.View; 
    import android.view.View.OnClickListener; 
    import android.widget.Button; 
    import android.widget.EditText; 
    import android.widget.ImageView; 
    import android.widget.TextView; 

    public class NewappActivity extends Activity { 
     ImageView iv= null; 

    /** Called when the activity is first created. */ 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 

     super.onCreate(savedInstanceState); 
     setContentView(R.layout.main); 
     iv=(ImageView) findViewById(R.id.im1); 
     iv.setVisibility(View.INVISIBLE); 
     Button btn=(Button) findViewById(R.id.enter); 
     btn.setOnClickListener(new OnClickListener() { 

      @Override 
      public void onClick(View v) { 
       // TODO Auto-generated method stub 
       String pwd="pd"; 
       EditText et=(EditText) findViewById(R.id.pwd); 
       if(et.getText().toString().equalsIgnoreCase(pwd)) 
       { 

        iv.setVisibility(View.VISIBLE); 
       } 

      } 
     }); 
    }