java“必须调用setView”自定义类扩展按钮
所以我有一个12 x 9的“按钮”网格,称为“瓷砖”。 瓦片java扩展了小部件“按钮”
不过我现在遇到了一个问题,我试图让按钮显示一个吐司,让它回忆起按下按钮的ID
网格是动态添加的,我希望它保持这种状态
这是GameBoardActivity的代码。爪哇:
这使12x9网格成为“分片”,并为每个分片添加一个侦听器
public void gridRowButtons(int iterations){
final Tile[] gridSpaces = new Tile[12];
LinearLayout.LayoutParams buttonParams = new LinearLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT, 1.0f);
for (int i = 0; i < 12; i++) {
String idString = String.valueOf(aToI[iterations]) + String.valueOf(i + 1);
final int id = getResources().getIdentifier(idString, "id", getPackageName());
gridSpaces[i] = new Tile(getApplicationContext());
gridSpaces[i].setText("");
gridSpaces[i].setHeight(40);
gridSpaces[i].setWidth(40);
gridSpaces[i].setLayoutParams(buttonParams);
gridSpaces[i].setId(id);
OnClickListener showID = new OnClickListener(){
public void onClick(View view){
TextView text = (TextView) findViewById(R.id.tileIDText);
String tileID = getApplicationContext().getResources().getResourceEntryName(id);
text.setText(tileID);
Tile clickedTile = (Tile) findViewById(id);
clickedTile.tileClick(0, tileID);
}
};
gridSpaces[i].setOnClickListener(showID);
}
LinearLayout buttonRow = new LinearLayout(getApplicationContext());
buttonRow.setOrientation(LinearLayout.HORIZONTAL);
buttonRow.setLayoutParams(buttonParams);
LinearLayout boardSpace = (LinearLayout) this.findViewById(R.id.boardLayout);
for (int i = 0; i < gridSpaces.length; i++) {
buttonRow.addView(gridSpaces[i]);
}
boardSpace.addView(buttonRow);
}
这是上面提到的tileClick方法:
public void tileClick(int action, String tileID) {
switch(action) {
case 1 :
//action 1
case 2 :
//action 2
default :
Context context = getContext();
Toast toast = new Toast(context);
Toast.makeText(context, tileID, Toast.LENGTH_SHORT);
toast.show();
}
}
LogCat显示以下内容:
02-22 20:45:14.623: E/AndroidRuntime(7868): FATAL EXCEPTION: main
02-22 20:45:14.623: E/AndroidRuntime(7868): java.lang.RuntimeException: setView must have been called
02-22 20:45:14.623: E/AndroidRuntime(7868): at 安卓.widget.Toast.show(Toast.java:103)
02-22 20:45:14.623: E/AndroidRuntime(7868): at com.jneal.ecquire.Tile.tileClick(Tile.java:51)
02-22 20:45:14.623: E/AndroidRuntime(7868): at com.jneal.ecquire.GameBoardActivity$1.onClick(GameBoardActivity.java:55)
02-22 20:45:14.623: E/AndroidRuntime(7868): at 安卓.view.View.performClick(View.java:3627)
02-22 20:45:14.623: E/AndroidRuntime(7868): at 安卓.view.View$PerformClick.run(View.java:14329)
02-22 20:45:14.623: E/AndroidRuntime(7868): at 安卓.os.Handler.handleCallback(Handler.java:605)
02-22 20:45:14.623: E/AndroidRuntime(7868): at 安卓.os.Handler.dispatchMessage(Handler.java:92)
02-22 20:45:14.623: E/AndroidRuntime(7868): at 安卓.os.Looper.loop(Looper.java:137)
02-22 20:45:14.623: E/AndroidRuntime(7868): at 安卓.app.ActivityThread.main(ActivityThread.java:4511)
02-22 20:45:14.623: E/AndroidRuntime(7868): at java.lang.reflect.Method.invokeNative(Native Method)
02-22 20:45:14.623: E/AndroidRuntime(7868): at java.lang.reflect.Method.invoke(Method.java:511)
02-22 20:45:14.623: E/AndroidRuntime(7868): at com.安卓.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:976)
02-22 20:45:14.623: E/AndroidRuntime(7868): at com.安卓.internal.os.ZygoteInit.main(ZygoteInit.java:743)
02-22 20:45:14.623: E/AndroidRuntime(7868): at dalvik.system.NativeStart.main(Native Method)
发生什么事了?我的main活动中显示祝酒词的代码几乎完全相同。java,它执行起来没有问题。 是因为我扩展了按钮,但它不知道视图已经是什么了吗? 此外,出于某种原因,Eclipse不允许我添加setView()。我肯定这里有封装问题,但我不清楚它们是什么。 提前谢谢你的帮助。 JRad
# 1 楼答案
将下面的代码行更改为下面的代码行:
更改为:
从源代码中可以看到,只有当mNextView为null时才会引发该异常。 函数“makeText”应该设置它,它确实设置了,但是您的原始代码没有捕获对它构建的Toast的引用。相反,您的原始代码创建两个祝酒词,并尝试“显示”尚未设置其视图的祝酒词